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Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
/* Inferior iterators and ranges for GDB, the GNU debugger.
Update copyright year range in all GDB files. gdb/ChangeLog: Update copyright year range in all GDB files.
2020-01-01 07:20:01 +01:00
Copyright (C) 2018-2020 Free Software Foundation, Inc.
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef INFERIOR_ITER_H
#define INFERIOR_ITER_H
Rename common to gdbsupport This is the next patch in the ongoing series to move gdbsever to the top level. This patch just renames the "common" directory. The idea is to do this move in two parts: first rename the directory (this patch), then move the directory to the top. This approach makes the patches a bit more tractable. I chose the name "gdbsupport" for the directory. However, as this patch was largely written by sed, we could pick a new name without too much difficulty. Tested by the buildbot. gdb/ChangeLog 2019-07-09 Tom Tromey <tom@tromey.com> * contrib/ari/gdb_ari.sh: Change common to gdbsupport. * configure: Rebuild. * configure.ac: Change common to gdbsupport. * gdbsupport: Rename from common. * acinclude.m4: Change common to gdbsupport. * Makefile.in (CONFIG_SRC_SUBDIR, COMMON_SFILES) (HFILES_NO_SRCDIR, stamp-version, ALLDEPFILES): Change common to gdbsupport. * aarch64-tdep.c, ada-lang.c, ada-lang.h, agent.c, alloc.c, amd64-darwin-tdep.c, amd64-dicos-tdep.c, amd64-fbsd-nat.c, amd64-fbsd-tdep.c, amd64-linux-nat.c, amd64-linux-tdep.c, amd64-nbsd-tdep.c, amd64-obsd-tdep.c, amd64-sol2-tdep.c, amd64-tdep.c, amd64-windows-tdep.c, arch-utils.c, arch/aarch64-insn.c, arch/aarch64.c, arch/aarch64.h, arch/amd64.c, arch/amd64.h, arch/arm-get-next-pcs.c, arch/arm-linux.c, arch/arm.c, arch/i386.c, arch/i386.h, arch/ppc-linux-common.c, arch/riscv.c, arch/riscv.h, arch/tic6x.c, arm-tdep.c, auto-load.c, auxv.c, ax-gdb.c, ax-general.c, ax.h, breakpoint.c, breakpoint.h, btrace.c, btrace.h, build-id.c, build-id.h, c-lang.h, charset.c, charset.h, cli/cli-cmds.c, cli/cli-cmds.h, cli/cli-decode.c, cli/cli-dump.c, cli/cli-option.h, cli/cli-script.c, coff-pe-read.c, command.h, compile/compile-c-support.c, compile/compile-c.h, compile/compile-cplus-symbols.c, compile/compile-cplus-types.c, compile/compile-cplus.h, compile/compile-loc2c.c, compile/compile.c, completer.c, completer.h, contrib/ari/gdb_ari.sh, corefile.c, corelow.c, cp-support.c, cp-support.h, cp-valprint.c, csky-tdep.c, ctf.c, darwin-nat.c, debug.c, defs.h, disasm-selftests.c, disasm.c, disasm.h, dtrace-probe.c, dwarf-index-cache.c, dwarf-index-cache.h, dwarf-index-write.c, dwarf2-frame.c, dwarf2expr.c, dwarf2loc.c, dwarf2read.c, event-loop.c, event-top.c, exceptions.c, exec.c, extension.h, fbsd-nat.c, features/aarch64-core.c, features/aarch64-fpu.c, features/aarch64-pauth.c, features/aarch64-sve.c, features/i386/32bit-avx.c, features/i386/32bit-avx512.c, features/i386/32bit-core.c, features/i386/32bit-linux.c, features/i386/32bit-mpx.c, features/i386/32bit-pkeys.c, features/i386/32bit-segments.c, features/i386/32bit-sse.c, features/i386/64bit-avx.c, features/i386/64bit-avx512.c, features/i386/64bit-core.c, features/i386/64bit-linux.c, features/i386/64bit-mpx.c, features/i386/64bit-pkeys.c, features/i386/64bit-segments.c, features/i386/64bit-sse.c, features/i386/x32-core.c, features/riscv/32bit-cpu.c, features/riscv/32bit-csr.c, features/riscv/32bit-fpu.c, features/riscv/64bit-cpu.c, features/riscv/64bit-csr.c, features/riscv/64bit-fpu.c, features/tic6x-c6xp.c, features/tic6x-core.c, features/tic6x-gp.c, filename-seen-cache.h, findcmd.c, findvar.c, fork-child.c, gcore.c, gdb_bfd.c, gdb_bfd.h, gdb_proc_service.h, gdb_regex.c, gdb_select.h, gdb_usleep.c, gdbarch-selftests.c, gdbthread.h, gdbtypes.h, gnu-nat.c, go32-nat.c, guile/guile.c, guile/scm-ports.c, guile/scm-safe-call.c, guile/scm-type.c, i386-fbsd-nat.c, i386-fbsd-tdep.c, i386-go32-tdep.c, i386-linux-nat.c, i386-linux-tdep.c, i386-tdep.c, i387-tdep.c, ia64-libunwind-tdep.c, ia64-linux-nat.c, inf-child.c, inf-ptrace.c, infcall.c, infcall.h, infcmd.c, inferior-iter.h, inferior.c, inferior.h, inflow.c, inflow.h, infrun.c, infrun.h, inline-frame.c, language.h, linespec.c, linux-fork.c, linux-nat.c, linux-tdep.c, linux-thread-db.c, location.c, machoread.c, macrotab.h, main.c, maint.c, maint.h, memattr.c, memrange.h, mi/mi-cmd-break.h, mi/mi-cmd-env.c, mi/mi-cmd-stack.c, mi/mi-cmd-var.c, mi/mi-interp.c, mi/mi-main.c, mi/mi-parse.h, minsyms.c, mips-linux-tdep.c, namespace.h, nat/aarch64-linux-hw-point.c, nat/aarch64-linux-hw-point.h, nat/aarch64-linux.c, nat/aarch64-sve-linux-ptrace.c, nat/amd64-linux-siginfo.c, nat/fork-inferior.c, nat/linux-btrace.c, nat/linux-btrace.h, nat/linux-namespaces.c, nat/linux-nat.h, nat/linux-osdata.c, nat/linux-personality.c, nat/linux-procfs.c, nat/linux-ptrace.c, nat/linux-ptrace.h, nat/linux-waitpid.c, nat/mips-linux-watch.c, nat/mips-linux-watch.h, nat/ppc-linux.c, nat/x86-dregs.c, nat/x86-dregs.h, nat/x86-linux-dregs.c, nat/x86-linux.c, nto-procfs.c, nto-tdep.c, objfile-flags.h, objfiles.c, objfiles.h, obsd-nat.c, observable.h, osdata.c, p-valprint.c, parse.c, parser-defs.h, ppc-linux-nat.c, printcmd.c, probe.c, proc-api.c, procfs.c, producer.c, progspace.h, psymtab.h, python/py-framefilter.c, python/py-inferior.c, python/py-ref.h, python/py-type.c, python/python.c, record-btrace.c, record-full.c, record.c, record.h, regcache-dump.c, regcache.c, regcache.h, remote-fileio.c, remote-fileio.h, remote-sim.c, remote.c, riscv-tdep.c, rs6000-aix-tdep.c, rust-exp.y, s12z-tdep.c, selftest-arch.c, ser-base.c, ser-event.c, ser-pipe.c, ser-tcp.c, ser-unix.c, skip.c, solib-aix.c, solib-target.c, solib.c, source-cache.c, source.c, source.h, sparc-nat.c, spu-linux-nat.c, stack.c, stap-probe.c, symfile-add-flags.h, symfile.c, symfile.h, symtab.c, symtab.h, target-descriptions.c, target-descriptions.h, target-memory.c, target.c, target.h, target/waitstatus.c, target/waitstatus.h, thread-iter.h, thread.c, tilegx-tdep.c, top.c, top.h, tracefile-tfile.c, tracefile.c, tracepoint.c, tracepoint.h, tui/tui-io.c, ui-file.c, ui-out.h, unittests/array-view-selftests.c, unittests/child-path-selftests.c, unittests/cli-utils-selftests.c, unittests/common-utils-selftests.c, unittests/copy_bitwise-selftests.c, unittests/environ-selftests.c, unittests/format_pieces-selftests.c, unittests/function-view-selftests.c, unittests/lookup_name_info-selftests.c, unittests/memory-map-selftests.c, unittests/memrange-selftests.c, unittests/mkdir-recursive-selftests.c, unittests/observable-selftests.c, unittests/offset-type-selftests.c, unittests/optional-selftests.c, unittests/parse-connection-spec-selftests.c, unittests/ptid-selftests.c, unittests/rsp-low-selftests.c, unittests/scoped_fd-selftests.c, unittests/scoped_mmap-selftests.c, unittests/scoped_restore-selftests.c, unittests/string_view-selftests.c, unittests/style-selftests.c, unittests/tracepoint-selftests.c, unittests/unpack-selftests.c, unittests/utils-selftests.c, unittests/xml-utils-selftests.c, utils.c, utils.h, valarith.c, valops.c, valprint.c, value.c, value.h, varobj.c, varobj.h, windows-nat.c, x86-linux-nat.c, xml-support.c, xml-support.h, xml-tdesc.h, xstormy16-tdep.c, xtensa-linux-nat.c, dwarf2read.h: Change common to gdbsupport. gdb/gdbserver/ChangeLog 2019-07-09 Tom Tromey <tom@tromey.com> * configure: Rebuild. * configure.ac: Change common to gdbsupport. * acinclude.m4: Change common to gdbsupport. * Makefile.in (SFILES, OBS, GDBREPLAY_OBS, IPA_OBJS) (version-generated.c, gdbsupport/%-ipa.o, gdbsupport/%.o): Change common to gdbsupport. * ax.c, event-loop.c, fork-child.c, gdb_proc_service.h, gdbreplay.c, gdbthread.h, hostio-errno.c, hostio.c, i387-fp.c, inferiors.c, inferiors.h, linux-aarch64-tdesc-selftest.c, linux-amd64-ipa.c, linux-i386-ipa.c, linux-low.c, linux-tic6x-low.c, linux-x86-low.c, linux-x86-tdesc-selftest.c, linux-x86-tdesc.c, lynx-i386-low.c, lynx-low.c, mem-break.h, nto-x86-low.c, regcache.c, regcache.h, remote-utils.c, server.c, server.h, spu-low.c, symbol.c, target.h, tdesc.c, tdesc.h, thread-db.c, tracepoint.c, win32-i386-low.c, win32-low.c: Change common to gdbsupport.
2019-05-06 04:29:24 +02:00
#include "gdbsupport/filtered-iterator.h"
#include "gdbsupport/safe-iterator.h"
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
/* A forward iterator that iterates over all inferiors. */
class all_inferiors_iterator
{
public:
typedef all_inferiors_iterator self_type;
typedef struct inferior *value_type;
typedef struct inferior *&reference;
typedef struct inferior **pointer;
typedef std::forward_iterator_tag iterator_category;
typedef int difference_type;
/* Create an iterator pointing at HEAD. */
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
all_inferiors_iterator (process_stratum_target *proc_target, inferior *head)
: m_proc_target (proc_target)
{
/* Advance M_INF to the first inferior's position. */
for (m_inf = head; m_inf != NULL; m_inf = m_inf->next)
if (m_inf_matches ())
return;
}
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
/* Create a one-past-end iterator. */
all_inferiors_iterator ()
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
: m_proc_target (nullptr), m_inf (nullptr)
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
{}
all_inferiors_iterator &operator++ ()
{
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
advance ();
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
return *this;
}
inferior *operator* () const
{ return m_inf; }
bool operator!= (const all_inferiors_iterator &other) const
{ return m_inf != other.m_inf; }
private:
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
/* Advance to next inferior, skipping filtered inferiors. */
void advance ()
{
/* The loop below is written in the natural way as-if we'd always
start at the beginning of the inferior list. This
fast-forwards the algorithm to the actual current position. */
goto start;
while (m_inf != NULL)
{
if (m_inf_matches ())
return;
start:
m_inf = m_inf->next;
}
}
bool m_inf_matches ()
{
return (m_proc_target == nullptr
|| m_proc_target == m_inf->process_target ());
}
process_stratum_target *m_proc_target;
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
inferior *m_inf;
};
/* Filter for filtered_iterator. Filters out exited inferiors. */
struct exited_inferior_filter
{
bool operator() (inferior *inf)
{
return inf->pid != 0;
}
};
/* Iterate over all non-exited inferiors. */
using all_non_exited_inferiors_iterator
= filtered_iterator<all_inferiors_iterator, exited_inferior_filter>;
/* A range adapter that makes it possible to iterate over all
inferiors with range-for. */
struct all_inferiors_range
{
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
all_inferiors_range (process_stratum_target *proc_target = nullptr)
: m_filter_target (proc_target)
{}
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
all_inferiors_iterator begin () const
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
{ return all_inferiors_iterator (m_filter_target, inferior_list); }
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
all_inferiors_iterator end () const
{ return all_inferiors_iterator (); }
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
private:
process_stratum_target *m_filter_target;
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
};
/* Iterate over all inferiors, safely. */
using all_inferiors_safe_iterator
= basic_safe_iterator<all_inferiors_iterator>;
/* A range adapter that makes it possible to iterate over all
inferiors with range-for "safely". I.e., it is safe to delete the
currently-iterated inferior. */
struct all_inferiors_safe_range
{
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
explicit all_inferiors_safe_range (process_stratum_target *filter_target)
: m_filter_target (filter_target)
{}
all_inferiors_safe_range ()
: m_filter_target (nullptr)
{}
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
all_inferiors_safe_iterator begin () const
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
{
return (all_inferiors_safe_iterator
(all_inferiors_iterator (m_filter_target, inferior_list)));
}
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
all_inferiors_safe_iterator end () const
{ return all_inferiors_safe_iterator (); }
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
private:
/* The filter. */
process_stratum_target *m_filter_target;
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
};
/* A range adapter that makes it possible to iterate over all
non-exited inferiors with range-for. */
struct all_non_exited_inferiors_range
{
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
explicit all_non_exited_inferiors_range (process_stratum_target *filter_target)
: m_filter_target (filter_target)
{}
all_non_exited_inferiors_range ()
: m_filter_target (nullptr)
{}
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
all_non_exited_inferiors_iterator begin () const
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
{ return all_non_exited_inferiors_iterator (m_filter_target, inferior_list); }
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
all_non_exited_inferiors_iterator end () const
{ return all_non_exited_inferiors_iterator (); }
Multi-target support This commit adds multi-target support to GDB. What this means is that with this commit, GDB can now be connected to different targets at the same time. E.g., you can debug a live native process and a core dump at the same time, connect to multiple gdbservers, etc. Actually, the word "target" is overloaded in gdb. We already have a target stack, with pushes several target_ops instances on top of one another. We also have "info target" already, which means something completely different to what this patch does. So from here on, I'll be using the "target connections" term, to mean an open process_stratum target, pushed on a target stack. This patch makes gdb have multiple target stacks, and multiple process_stratum targets open simultaneously. The user-visible changes / commands will also use this terminology, but of course it's all open to debate. User-interface-wise, not that much changes. The main difference is that each inferior may have its own target connection. A target connection (e.g., a target extended-remote connection) may support debugging multiple processes, just as before. Say you're debugging against gdbserver in extended-remote mode, and you do "add-inferior" to prepare to spawn a new process, like: (gdb) target extended-remote :9999 ... (gdb) start ... (gdb) add-inferior Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) file a.out ... (gdb) start ... At this point, you have two inferiors connected to the same gdbserver. With this commit, GDB will maintain a target stack per inferior, instead of a global target stack. To preserve the behavior above, by default, "add-inferior" makes the new inferior inherit a copy of the target stack of the current inferior. Same across a fork - the child inherits a copy of the target stack of the parent. While the target stacks are copied, the targets themselves are not. Instead, target_ops is made a refcounted_object, which means that target_ops instances are refcounted, which each inferior counting for a reference. What if you want to create an inferior and connect it to some _other_ target? For that, this commit introduces a new "add-inferior -no-connection" option that makes the new inferior not share the current inferior's target. So you could do: (gdb) target extended-remote :9999 Remote debugging using :9999 ... (gdb) add-inferior -no-connection [New inferior 2] Added inferior 2 (gdb) inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 <null> (gdb) tar extended-remote :10000 Remote debugging using :10000 ... (gdb) info inferiors Num Description Executable 1 process 18401 target:/home/pedro/tmp/main * 2 process 18450 target:/home/pedro/tmp/main (gdb) A following patch will extended "info inferiors" to include a column indicating which connection an inferior is bound to, along with a couple other UI tweaks. Other than that, debugging is the same as before. Users interact with inferiors and threads as before. The only difference is that inferiors may be bound to processes running in different machines. That's pretty much all there is to it in terms of noticeable UI changes. On to implementation. Since we can be connected to different systems at the same time, a ptid_t is no longer a unique identifier. Instead a thread can be identified by a pair of ptid_t and 'process_stratum_target *', the later being the instance of the process_stratum target that owns the process/thread. Note that process_stratum_target inherits from target_ops, and all process_stratum targets inherit from process_stratum_target. In earlier patches, many places in gdb were converted to refer to threads by thread_info pointer instead of ptid_t, but there are still places in gdb where we start with a pid/tid and need to find the corresponding inferior or thread_info objects. So you'll see in the patch many places adding a process_stratum_target parameter to functions that used to take only a ptid_t. Since each inferior has its own target stack now, we can always find the process_stratum target for an inferior. That is done via a inf->process_target() convenience method. Since each inferior has its own target stack, we need to handle the "beneath" calls when servicing target calls. The solution I settled with is just to make sure to switch the current inferior to the inferior you want before making a target call. Not relying on global context is just not feasible in current GDB. Fortunately, there aren't that many places that need to do that, because generally most code that calls target methods already has the current context pointing to the right inferior/thread. Note, to emphasize -- there's no method to "switch to this target stack". Instead, you switch the current inferior, and that implicitly switches the target stack. In some spots, we need to iterate over all inferiors so that we reach all target stacks. Native targets are still singletons. There's always only a single instance of such targets. Remote targets however, we'll have one instance per remote connection. The exec target is still a singleton. There's only one instance. I did not see the point of instanciating more than one exec_target object. After vfork, we need to make sure to push the exec target on the new inferior. See exec_on_vfork. For type safety, functions that need a {target, ptid} pair to identify a thread, take a process_stratum_target pointer for target parameter instead of target_ops *. Some shared code in gdb/nat/ also need to gain a target pointer parameter. This poses an issue, since gdbserver doesn't have process_stratum_target, only target_ops. To fix this, this commit renames gdbserver's target_ops to process_stratum_target. I think this makes sense. There's no concept of target stack in gdbserver, and gdbserver's target_ops really implements a process_stratum-like target. The thread and inferior iterator functions also gain process_stratum_target parameters. These are used to be able to iterate over threads and inferiors of a given target. Following usual conventions, if the target pointer is null, then we iterate over threads and inferiors of all targets. I tried converting "add-inferior" to the gdb::option framework, as a preparatory patch, but that stumbled on the fact that gdb::option does not support file options yet, for "add-inferior -exec". I have a WIP patchset that adds that, but it's not a trivial patch, mainly due to need to integrate readline's filename completion, so I deferred that to some other time. In infrun.c/infcmd.c, the main change is that we need to poll events out of all targets. See do_target_wait. Right after collecting an event, we switch the current inferior to an inferior bound to the target that reported the event, so that target methods can be used while handling the event. This makes most of the code transparent to multi-targets. See fetch_inferior_event. infrun.c:stop_all_threads is interesting -- in this function we need to stop all threads of all targets. What the function does is send an asynchronous stop request to all threads, and then synchronously waits for events, with target_wait, rinse repeat, until all it finds are stopped threads. Now that we have multiple targets, it's not efficient to synchronously block in target_wait waiting for events out of one target. Instead, we implement a mini event loop, with interruptible_select, select'ing on one file descriptor per target. For this to work, we need to be able to ask the target for a waitable file descriptor. Such file descriptors already exist, they are the descriptors registered in the main event loop with add_file_handler, inside the target_async implementations. This commit adds a new target_async_wait_fd target method that just returns the file descriptor in question. See wait_one / stop_all_threads in infrun.c. The 'threads_executing' global is made a per-target variable. Since it is only relevant to process_stratum_target targets, this is where it is put, instead of in target_ops. You'll notice that remote.c includes some FIXME notes. These refer to the fact that the global arrays that hold data for the remote packets supported are still globals. For example, if we connect to two different servers/stubs, then each might support different remote protocol features. They might even be different architectures, like e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a host/controller scenario as a single program. That isn't going to work correctly today, because of said globals. I'm leaving fixing that for another pass, since it does not appear to be trivial, and I'd rather land the base work first. It's already useful to be able to debug multiple instances of the same server (e.g., a distributed cluster, where you have full control over the servers installed), so I think as is it's already reasonable incremental progress. Current limitations: - You can only resume more that one target at the same time if all targets support asynchronous debugging, and support non-stop mode. It should be possible to support mixed all-stop + non-stop backends, but that is left for another time. This means that currently in order to do multi-target with gdbserver you need to issue "maint set target-non-stop on". I would like to make that mode be the default, but we're not there yet. Note that I'm talking about how the target backend works, only. User-visible all-stop mode works just fine. - As explained above, connecting to different remote servers at the same time is likely to produce bad results if they don't support the exact set of RSP features. FreeBSD updates courtesy of John Baldwin. gdb/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> John Baldwin <jhb@FreeBSD.org> * aarch64-linux-nat.c (aarch64_linux_nat_target::thread_architecture): Adjust. * ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call. (task_command_1): Likewise. * aix-thread.c (sync_threadlists, aix_thread_target::resume) (aix_thread_target::wait, aix_thread_target::fetch_registers) (aix_thread_target::store_registers) (aix_thread_target::thread_alive): Adjust. * amd64-fbsd-tdep.c: Include "inferior.h". (amd64fbsd_get_thread_local_address): Pass down target. * amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle thread's gdbarch instead of target_gdbarch. * break-catch-sig.c (signal_catchpoint_print_it): Adjust call to get_last_target_status. * break-catch-syscall.c (print_it_catch_syscall): Likewise. * breakpoint.c (breakpoints_should_be_inserted_now): Consider all inferiors. (update_inserted_breakpoint_locations): Skip if inferiors with no execution. (update_global_location_list): When handling moribund locations, find representative inferior for location's pspace, and use thread count of its process_stratum target. * bsd-kvm.c (bsd_kvm_target_open): Pass target down. * bsd-uthread.c (bsd_uthread_target::wait): Use as_process_stratum_target and adjust thread_change_ptid and add_thread calls. (bsd_uthread_target::update_thread_list): Use as_process_stratum_target and adjust find_thread_ptid, thread_change_ptid and add_thread calls. * btrace.c (maint_btrace_packet_history_cmd): Adjust find_thread_ptid call. * corelow.c (add_to_thread_list): Adjust add_thread call. (core_target_open): Adjust add_thread_silent and thread_count calls. (core_target::pid_to_str): Adjust find_inferior_ptid call. * ctf.c (ctf_target_open): Adjust add_thread_silent call. * event-top.c (async_disconnect): Pop targets from all inferiors. * exec.c (add_target_sections): Push exec target on all inferiors sharing the program space. (remove_target_sections): Remove the exec target from all inferiors sharing the program space. (exec_on_vfork): New. * exec.h (exec_on_vfork): Declare. * fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::update_thread_list): Adjust. (fbsd_nat_target::resume): Adjust. (fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it down. (fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust. * fbsd-tdep.c (fbsd_corefile_thread): Adjust get_thread_arch_regcache call. * fork-child.c (gdb_startup_inferior): Pass target down to startup_inferior and set_executing. * gdbthread.h (struct process_stratum_target): Forward declare. (add_thread, add_thread_silent, add_thread_with_info) (in_thread_list): Add process_stratum_target parameter. (find_thread_ptid(inferior*, ptid_t)): New overload. (find_thread_ptid, thread_change_ptid): Add process_stratum_target parameter. (all_threads()): Delete overload. (all_threads, all_non_exited_threads): Add process_stratum_target parameter. (all_threads_safe): Use brace initialization. (thread_count): Add process_stratum_target parameter. (set_resumed, set_running, set_stop_requested, set_executing) (threads_are_executing, finish_thread_state): Add process_stratum_target parameter. (switch_to_thread): Use is_current_thread. * i386-fbsd-tdep.c: Include "inferior.h". (i386fbsd_get_thread_local_address): Pass down target. * i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust. * inf-child.c (inf_child_target::maybe_unpush_target): Remove have_inferiors check. * inf-ptrace.c (inf_ptrace_target::create_inferior) (inf_ptrace_target::attach): Adjust. * infcall.c (run_inferior_call): Adjust. * infcmd.c (run_command_1): Pass target to scoped_finish_thread_state. (proceed_thread_callback): Skip inferiors with no execution. (continue_command): Rename 'all_threads' local to avoid hiding 'all_threads' function. Adjust get_last_target_status call. (prepare_one_step): Adjust set_running call. (signal_command): Use user_visible_resume_target. Compare thread pointers instead of inferior_ptid. (info_program_command): Adjust to pass down target. (attach_command): Mark target's 'thread_executing' flag. (stop_current_target_threads_ns): New, factored out from ... (interrupt_target_1): ... this. Switch inferior before making target calls. * inferior-iter.h (struct all_inferiors_iterator, struct all_inferiors_range) (struct all_inferiors_safe_range) (struct all_non_exited_inferiors_range): Filter on process_stratum_target too. Remove explicit. * inferior.c (inferior::inferior): Push dummy target on target stack. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors): Add process_stratum_target parameter, and pass it down. (have_live_inferiors): Adjust. (switch_to_inferior_and_push_target): New. (add_inferior_command, clone_inferior_command): Handle "-no-connection" parameter. Use switch_to_inferior_and_push_target. (_initialize_inferior): Mention "-no-connection" option in the help of "add-inferior" and "clone-inferior" commands. * inferior.h: Include "process-stratum-target.h". (interrupt_target_1): Use bool. (struct inferior) <push_target, unpush_target, target_is_pushed, find_target_beneath, top_target, process_target, target_at, m_stack>: New. (discard_all_inferiors): Delete. (find_inferior_pid, find_inferior_ptid, number_of_live_inferiors) (all_inferiors, all_non_exited_inferiors): Add process_stratum_target parameter. * infrun.c: Include "gdb_select.h" and <unordered_map>. (target_last_proc_target): New global. (follow_fork_inferior): Push target on new inferior. Pass target to add_thread_silent. Call exec_on_vfork. Handle target's reference count. (follow_fork): Adjust get_last_target_status call. Also consider target. (follow_exec): Push target on new inferior. (struct execution_control_state) <target>: New field. (user_visible_resume_target): New. (do_target_resume): Call target_async. (resume_1): Set target's threads_executing flag. Consider resume target. (commit_resume_all_targets): New. (proceed): Also consider resume target. Skip threads of inferiors with no execution. Commit resumtion in all targets. (start_remote): Pass current inferior to wait_for_inferior. (infrun_thread_stop_requested): Consider target as well. Pass thread_info pointer to clear_inline_frame_state instead of ptid. (infrun_thread_thread_exit): Consider target as well. (random_pending_event_thread): New inferior parameter. Use it. (do_target_wait): Rename to ... (do_target_wait_1): ... this. Add inferior parameter, and pass it down. (threads_are_resumed_pending_p, do_target_wait): New. (prepare_for_detach): Adjust calls. (wait_for_inferior): New inferior parameter. Handle it. Use do_target_wait_1 instead of do_target_wait. (fetch_inferior_event): Adjust. Switch to representative inferior. Pass target down. (set_last_target_status): Add process_stratum_target parameter. Save target in global. (get_last_target_status): Add process_stratum_target parameter and handle it. (nullify_last_target_wait_ptid): Clear 'target_last_proc_target'. (context_switch): Check inferior_ptid == null_ptid before calling inferior_thread(). (get_inferior_stop_soon): Pass down target. (wait_one): Rename to ... (poll_one_curr_target): ... this. (struct wait_one_event): New. (wait_one): New. (stop_all_threads): Adjust. (handle_no_resumed, handle_inferior_event): Adjust to consider the event's target. (switch_back_to_stepped_thread): Also consider target. (print_stop_event): Update. (normal_stop): Update. Also consider the resume target. * infrun.h (wait_for_inferior): Remove declaration. (user_visible_resume_target): New declaration. (get_last_target_status, set_last_target_status): New process_stratum_target parameter. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter, and use it. (clear_inline_frame_state (thread_info*)): New. * inline-frame.c (clear_inline_frame_state(ptid_t)): Add process_stratum_target parameter. (clear_inline_frame_state (thread_info*)): Declare. * linux-fork.c (delete_checkpoint_command): Pass target down to find_thread_ptid. (checkpoint_command): Adjust. * linux-nat.c (linux_nat_target::follow_fork): Switch to thread instead of just tweaking inferior_ptid. (linux_nat_switch_fork): Pass target down to thread_change_ptid. (exit_lwp): Pass target down to find_thread_ptid. (attach_proc_task_lwp_callback): Pass target down to add_thread/set_running/set_executing. (linux_nat_target::attach): Pass target down to thread_change_ptid. (get_detach_signal): Pass target down to find_thread_ptid. Consider last target status's target. (linux_resume_one_lwp_throw, resume_lwp) (linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp) (stop_wait_callback, save_stop_reason, linux_nat_filter_event) (linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down. (linux_nat_target::async_wait_fd): New. (linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass target down. * linux-nat.h (linux_nat_target::async_wait_fd): Declare. * linux-tdep.c (get_thread_arch_regcache): Pass target down. * linux-thread-db.c (struct thread_db_info::process_target): New field. (add_thread_db_info): Save target. (get_thread_db_info): New process_stratum_target parameter. Also match target. (delete_thread_db_info): New process_stratum_target parameter. Also match target. (thread_from_lwp): Adjust to pass down target. (thread_db_notice_clone): Pass down target. (check_thread_db_callback): Pass down target. (try_thread_db_load_1): Always push the thread_db target. (try_thread_db_load, record_thread): Pass target down. (thread_db_target::detach): Pass target down. Always unpush the thread_db target. (thread_db_target::wait, thread_db_target::mourn_inferior): Pass target down. Always unpush the thread_db target. (find_new_threads_callback, thread_db_find_new_threads_2) (thread_db_target::update_thread_list): Pass target down. (thread_db_target::pid_to_str): Pass current inferior down. (thread_db_target::get_thread_local_address): Pass target down. (thread_db_target::resume, maintenance_check_libthread_db): Pass target down. * nto-procfs.c (nto_procfs_target::update_thread_list): Adjust. * procfs.c (procfs_target::procfs_init_inferior): Declare. (proc_set_current_signal, do_attach, procfs_target::wait): Adjust. (procfs_init_inferior): Rename to ... (procfs_target::procfs_init_inferior): ... this and adjust. (procfs_target::create_inferior, procfs_notice_thread) (procfs_do_thread_registers): Adjust. * ppc-fbsd-tdep.c: Include "inferior.h". (ppcfbsd_get_thread_local_address): Pass down target. * proc-service.c (ps_xfer_memory): Switch current inferior and program space as well. (get_ps_regcache): Pass target down. * process-stratum-target.c (process_stratum_target::thread_address_space) (process_stratum_target::thread_architecture): Pass target down. * process-stratum-target.h (process_stratum_target::threads_executing): New field. (as_process_stratum_target): New. * ravenscar-thread.c (ravenscar_thread_target::update_inferior_ptid): Pass target down. (ravenscar_thread_target::wait, ravenscar_add_thread): Pass target down. * record-btrace.c (record_btrace_target::info_record): Adjust. (record_btrace_target::record_method) (record_btrace_target::record_is_replaying) (record_btrace_target::fetch_registers) (get_thread_current_frame_id, record_btrace_target::resume) (record_btrace_target::wait, record_btrace_target::stop): Pass target down. * record-full.c (record_full_wait_1): Switch to event thread. Pass target down. * regcache.c (regcache::regcache) (get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add process_stratum_target parameter and handle it. (current_thread_target): New global. (get_thread_regcache): Add process_stratum_target parameter and handle it. Switch inferior before calling target method. (get_thread_regcache): Pass target down. (get_thread_regcache_for_ptid): Pass target down. (registers_changed_ptid): Add process_stratum_target parameter and handle it. (registers_changed_thread, registers_changed): Pass target down. (test_get_thread_arch_aspace_regcache): New. (current_regcache_test): Define a couple local test_target_ops instances and use them for testing. (readwrite_regcache): Pass process_stratum_target parameter. (cooked_read_test, cooked_write_test): Pass mock_target down. * regcache.h (get_thread_regcache, get_thread_arch_regcache) (get_thread_arch_aspace_regcache): Add process_stratum_target parameter. (regcache::target): New method. (regcache::regcache, regcache::get_thread_arch_aspace_regcache) (regcache::registers_changed_ptid): Add process_stratum_target parameter. (regcache::m_target): New field. (registers_changed_ptid): Add process_stratum_target parameter. * remote.c (remote_state::supports_vCont_probed): New field. (remote_target::async_wait_fd): New method. (remote_unpush_and_throw): Add remote_target parameter. (get_current_remote_target): Adjust. (remote_target::remote_add_inferior): Push target. (remote_target::remote_add_thread) (remote_target::remote_notice_new_inferior) (get_remote_thread_info): Pass target down. (remote_target::update_thread_list): Skip threads of inferiors bound to other targets. (remote_target::close): Don't discard inferiors. (remote_target::add_current_inferior_and_thread) (remote_target::process_initial_stop_replies) (remote_target::start_remote) (remote_target::remote_serial_quit_handler): Pass down target. (remote_target::remote_unpush_target): New remote_target parameter. Unpush the target from all inferiors. (remote_target::remote_unpush_and_throw): New remote_target parameter. Pass it down. (remote_target::open_1): Check whether the current inferior has execution instead of checking whether any inferior is live. Pass target down. (remote_target::remote_detach_1): Pass down target. Use remote_unpush_target. (extended_remote_target::attach): Pass down target. (remote_target::remote_vcont_probe): Set supports_vCont_probed. (remote_target::append_resumption): Pass down target. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc, remote_target::resume) (remote_target::commit_resume): Pass down target. (remote_target::remote_stop_ns): Check supports_vCont_probed. (remote_target::interrupt_query) (remote_target::remove_new_fork_children) (remote_target::check_pending_events_prevent_wildcard_vcont) (remote_target::remote_parse_stop_reply) (remote_target::process_stop_reply): Pass down target. (first_remote_resumed_thread): New remote_target parameter. Pass it down. (remote_target::wait_as): Pass down target. (unpush_and_perror): New remote_target parameter. Pass it down. (remote_target::readchar, remote_target::remote_serial_write) (remote_target::getpkt_or_notif_sane_1) (remote_target::kill_new_fork_children, remote_target::kill): Pass down target. (remote_target::mourn_inferior): Pass down target. Use remote_unpush_target. (remote_target::core_of_thread) (remote_target::remote_btrace_maybe_reopen): Pass down target. (remote_target::pid_to_exec_file) (remote_target::thread_handle_to_thread_info): Pass down target. (remote_target::async_wait_fd): New. * riscv-fbsd-tdep.c: Include "inferior.h". (riscv_fbsd_get_thread_local_address): Pass down target. * sol2-tdep.c (sol2_core_pid_to_str): Pass down target. * sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs) (ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback): Adjust. * solib-spu.c (spu_skip_standalone_loader): Pass down target. * solib-svr4.c (enable_break): Pass down target. * spu-multiarch.c (parse_spufs_run): Pass down target. * spu-tdep.c (spu2ppu_sniffer): Pass down target. * target-delegates.c: Regenerate. * target.c (g_target_stack): Delete. (current_top_target): Return the current inferior's top target. (target_has_execution_1): Refer to the passed-in inferior's top target. (target_supports_terminal_ours): Check whether the initial inferior was already created. (decref_target): New. (target_stack::push): Incref/decref the target. (push_target, push_target, unpush_target): Adjust. (target_stack::unpush): Defref target. (target_is_pushed): Return bool. Adjust to refer to the current inferior's target stack. (dispose_inferior): Delete, and inline parts ... (target_preopen): ... here. Only dispose of the current inferior. (target_detach): Hold strong target reference while detaching. Pass target down. (target_thread_name): Add assertion. (target_resume): Pass down target. (target_ops::beneath, find_target_at): Adjust to refer to the current inferior's target stack. (get_dummy_target): New. (target_pass_ctrlc): Pass the Ctrl-C to the first inferior that has a thread running. (initialize_targets): Rename to ... (_initialize_target): ... this. * target.h: Include "gdbsupport/refcounted-object.h". (struct target_ops): Inherit refcounted_object. (target_ops::shortname, target_ops::longname): Make const. (target_ops::async_wait_fd): New method. (decref_target): Declare. (struct target_ops_ref_policy): New. (target_ops_ref): New typedef. (get_dummy_target): Declare function. (target_is_pushed): Return bool. * thread-iter.c (all_matching_threads_iterator::m_inf_matches) (all_matching_threads_iterator::all_matching_threads_iterator): Handle filter target. * thread-iter.h (struct all_matching_threads_iterator, struct all_matching_threads_range, class all_non_exited_threads_range): Filter by target too. Remove explicit. * thread.c (threads_executing): Delete. (inferior_thread): Pass down current inferior. (clear_thread_inferior_resources): Pass down thread pointer instead of ptid_t. (add_thread_silent, add_thread_with_info, add_thread): Add process_stratum_target parameter. Use it for thread and inferior searches. (is_current_thread): New. (thread_info::deletable): Use it. (find_thread_ptid, thread_count, in_thread_list) (thread_change_ptid, set_resumed, set_running): New process_stratum_target parameter. Pass it down. (set_executing): New process_stratum_target parameter. Pass it down. Adjust reference to 'threads_executing'. (threads_are_executing): New process_stratum_target parameter. Adjust reference to 'threads_executing'. (set_stop_requested, finish_thread_state): New process_stratum_target parameter. Pass it down. (switch_to_thread): Also match inferior. (switch_to_thread): New process_stratum_target parameter. Pass it down. (update_threads_executing): Reimplement. * top.c (quit_force): Pop targets from all inferior. (gdb_init): Don't call initialize_targets. * windows-nat.c (windows_nat_target) <get_windows_debug_event>: Declare. (windows_add_thread, windows_delete_thread): Adjust. (get_windows_debug_event): Rename to ... (windows_nat_target::get_windows_debug_event): ... this. Adjust. * tracefile-tfile.c (tfile_target_open): Pass down target. * gdbsupport/common-gdbthread.h (struct process_stratum_target): Forward declare. (switch_to_thread): Add process_stratum_target parameter. * mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target parameter. Use it. (mi_on_resume): Pass target down. * nat/fork-inferior.c (startup_inferior): Add process_stratum_target parameter. Pass it down. * nat/fork-inferior.h (startup_inferior): Add process_stratum_target parameter. * python/py-threadevent.c (py_get_event_thread): Pass target down. gdb/gdbserver/ChangeLog: 2020-01-10 Pedro Alves <palves@redhat.com> * fork-child.c (post_fork_inferior): Pass target down to startup_inferior. * inferiors.c (switch_to_thread): Add process_stratum_target parameter. * lynx-low.c (lynx_target_ops): Now a process_stratum_target. * nto-low.c (nto_target_ops): Now a process_stratum_target. * linux-low.c (linux_target_ops): Now a process_stratum_target. * remote-utils.c (prepare_resume_reply): Pass the target to switch_to_thread. * target.c (the_target): Now a process_stratum_target. (done_accessing_memory): Pass the target to switch_to_thread. (set_target_ops): Ajust to use process_stratum_target. * target.h (struct target_ops): Rename to ... (struct process_stratum_target): ... this. (the_target, set_target_ops): Adjust. (prepare_to_access_memory): Adjust comment. * win32-low.c (child_xfer_memory): Adjust to use process_stratum_target. (win32_target_ops): Now a process_stratum_target.
2020-01-10 21:06:08 +01:00
private:
/* The filter. */
process_stratum_target *m_filter_target;
Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc. As preparation for multi-target, this patch makes each inferior have its own thread list. This isn't absolutely necessary for multi-target, but simplifies things. It originally stemmed from the desire to eliminate the init_thread_list calls sprinkled around, plus it makes it more efficient to iterate over threads of a given inferior (no need to always iterate over threads of all inferiors). We still need to iterate over threads of all inferiors in a number of places, which means we'd need adjust the ALL_THREADS / ALL_NON_EXITED_THREADS macros. However, naively tweaking those macros to have an extra for loop, like: #define ALL_THREADS (thr, inf) \ for (inf = inferior_list; inf; inf = inf->next) \ for (thr = inf->thread_list; thr; thr = thr->next) causes problems with code that does "break" or "continue" within the ALL_THREADS loop body. Plus, we need to declare the extra "inf" local variable in order to pass it as temporary variable to ALL_THREADS (etc.) It gets even trickier when we consider extending the macros to filter out threads matching a ptid_t and a target. The macros become tricker to read/write. Been there. An alternative (which was my next attempt), is to replace the ALL_THREADS etc. iteration style with for_each_all_threads, for_each_non_exited_threads, etc. functions which would take a callback as parameter, which would usually be passed a lambda. However, I did not find that satisfactory at all, because the resulting code ends up a little less natural / more noisy to read, write and debug/step-through (due to use of lambdas), and in many places where we use "continue;" to skip to the next thread now need to use "return;". (I ran into hard to debug bugs caused by a continue/return confusion.) I.e., before: ALL_NON_EXITED_THREADS (tp) { if (tp->not_what_I_want) continue; // do something } would turn into: for_each_non_exited_thread ([&] (thread_info *tp) { if (tp->not_what_I_want) return; // do something }); Lastly, the solution I settled with was to replace the ALL_THREADS / ALL_NON_EXITED_THREADS / ALL_INFERIORS macros with (C++20-like) ranges and iterators, such that you can instead naturaly iterate over threads/inferiors using range-for, like e.g,.: // all threads, including THREAD_EXITED threads. for (thread_info *tp : all_threads ()) { .... } // all non-exited threads. for (thread_info *tp : all_non_exited_threads ()) { .... } // all non-exited threads of INF inferior. for (thread_info *tp : inf->non_exited_threads ()) { .... } The all_non_exited_threads() function takes an optional filter ptid_t as parameter, which is quite convenient when we need to iterate over threads matching that filter. See e.g., how the set_executing/set_stop_requested/finish_thread_state etc. functions in thread.c end up being simplified. Most of the patch thus is about adding the infrustructure for allowing the above. Later on when we get to actual multi-target, these functions/ranges/iterators will gain a "target_ops *" parameter so that e.g., we can iterate over all threads of a given target that match a given filter ptid_t. The only entry points users needs to be aware of are the all_threads/all_non_exited_threads etc. functions seen above. Thus, those functions are declared in gdbthread.h/inferior.h. The actual iterators/ranges are mainly "internals" and thus are put out of view in the new thread-iter.h/thread-iter.c/inferior-iter.h files. That keeps the gdbthread.h/inferior.h headers quite a bit more readable. A common/safe-iterator.h header is added which adds a template that can be used to build "safe" iterators, which are forward iterators that can be used to replace the ALL_THREADS_SAFE macro and other instances of the same idiom in future. There's a little bit of shuffling of code between gdbthread.h/thread.c/inferior.h in the patch. That is necessary in order to avoid circular dependencies between the gdbthread.h/inferior.h headers. As for the init_thread_list calls sprinkled around, they're all eliminated by this patch, and a new, central call is added to inferior_appeared. Note how also related to that, there's a call to init_wait_for_inferior in remote.c that is eliminated. init_wait_for_inferior is currently responsible for discarding skipped inline frames, which had to be moved elsewhere. Given that nowadays we always have a thread even for single-threaded processes, the natural place is to delete a frame's inline frame info when we delete the thread. I.e., from clear_thread_inferior_resources. gdb/ChangeLog: 2018-11-22 Pedro Alves <palves@redhat.com> * Makefile.in (COMMON_SFILES): Add thread-iter.c. * breakpoint.c (breakpoints_should_be_inserted_now): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (print_one_breakpoint_location): Replace ALL_INFERIORS with all_inferiors. * bsd-kvm.c: Include inferior.h. * btrace.c (btrace_free_objfile): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * common/filtered-iterator.h: New. * common/safe-iterator.h: New. * corelow.c (core_target_open): Don't call init_thread_list here. * darwin-nat.c (thread_info_from_private_thread_info): Replace ALL_THREADS with all_threads. * fbsd-nat.c (fbsd_nat_target::resume): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fbsd-tdep.c (fbsd_make_corefile_notes): Replace ALL_NON_EXITED_THREADS with inf->non_exited_threads. * fork-child.c (postfork_hook): Don't call init_thread_list here. * gdbarch-selftests.c (register_to_value_test): Adjust. * gdbthread.h: Don't include "inferior.h" here. (struct inferior): Forward declare. (enum step_over_calls_kind): Moved here from inferior.h. (thread_info::deletable): Definition moved to thread.c. (find_thread_ptid (inferior *, ptid_t)): Declare. (ALL_THREADS, ALL_THREADS_BY_INFERIOR, ALL_THREADS_SAFE): Delete. Include "thread-iter.h". (all_threads, all_non_exited_threads, all_threads_safe): New. (any_thread_p): Declare. (thread_list): Delete. * infcmd.c (signal_command): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. (proceed_after_attach_callback): Delete. (proceed_after_attach): Take an inferior pointer instead of an integer PID. Adjust to use range-for. (attach_post_wait): Pass down inferior pointer instead of pid. Use range-for instead of ALL_NON_EXITED_THREADS. (detach_command): Remove init_thread_list call. * inferior-iter.h: New. * inferior.c (struct delete_thread_of_inferior_arg): Delete. (delete_thread_of_inferior): Delete. (delete_inferior, exit_inferior_1): Use range-for with inf->threads_safe() instead of iterate_over_threads. (inferior_appeared): Call init_thread_list here. (discard_all_inferiors): Use all_non_exited_inferiors. (find_inferior_id, find_inferior_pid): Use all_inferiors. (iterate_over_inferiors): Use all_inferiors_safe. (have_inferiors, number_of_live_inferiors): Use all_non_exited_inferiors. (number_of_inferiors): Use all_inferiors and std::distance. (print_inferior): Use all_inferiors. * inferior.h: Include gdbthread.h. (enum step_over_calls_kind): Moved to gdbthread.h. (struct inferior) <thread_list>: New field. <threads, non_exited_threads, threads_safe>: New methods. (ALL_INFERIORS): Delete. Include "inferior-iter.h". (ALL_NON_EXITED_INFERIORS): Delete. (all_inferiors_safe, all_inferiors, all_non_exited_inferiors): New functions. * inflow.c (child_interrupt, child_pass_ctrlc): Replace ALL_NON_EXITED_THREADS with all_non_exited_threads. * infrun.c (follow_exec): Use all_threads_safe. (clear_proceed_status, proceed): Use all_non_exited_threads. (init_wait_for_inferior): Don't clear inline frame state here. (infrun_thread_stop_requested, for_each_just_stopped_thread): Use all_threads instead of ALL_NON_EXITED_THREADS. (random_pending_event_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use a lambda for repeated code. (clean_up_just_stopped_threads_fsms): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (handle_no_resumed): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Use all_inferiors instead of ALL_INFERIORS. (restart_threads, switch_back_to_stepped_thread): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-nat.c (check_zombie_leaders): Replace ALL_INFERIORS with all_inferiors. (kill_unfollowed_fork_children): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-tdep.c (linux_make_corefile_notes): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * linux-thread-db.c (thread_db_target::update_thread_list): Replace ALL_INFERIORS with all_inferiors. (thread_db_target::thread_handle_to_thread_info): Use inf->non_exited_threads instead of ALL_NON_EXITED_THREADS. * mi/mi-interp.c (multiple_inferiors_p): New. (mi_on_resume_1): Simplify using all_non_exited_threads and multiple_inferiors_p. * mi/mi-main.c (mi_cmd_thread_list_ids): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * nto-procfs.c (nto_procfs_target::open): Don't call init_thread_list here. * record-btrace.c (record_btrace_target_open) (record_btrace_target::stop_recording) (record_btrace_target::close) (record_btrace_target::record_is_replaying) (record_btrace_target::resume, record_btrace_target::wait) (record_btrace_target::record_stop_replaying): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * record-full.c (record_full_wait_1): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * regcache.c (cooked_read_test): Remove reference to global thread_list. * remote-sim.c (gdbsim_target::create_inferior): Don't call init_thread_list here. * remote.c (remote_target::update_thread_list): Use all_threads_safe instead of ALL_NON_EXITED_THREADS. (remote_target::process_initial_stop_replies): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::open_1): Don't call init_thread_list here. (remote_target::append_pending_thread_resumptions) (remote_target::remote_resume_with_hc): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::commit_resume) (remote_target::remove_new_fork_children): Replace ALL_INFERIORS with all_non_exited_inferiors and use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. (remote_target::kill_new_fork_children): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. Remove init_thread_list and init_wait_for_inferior calls. (remote_target::remote_btrace_maybe_reopen) (remote_target::thread_handle_to_thread_info): Use all_non_exited_threads instead of ALL_NON_EXITED_THREADS. * target.c (target_terminal::restore_inferior) (target_terminal_is_ours_kind): Replace ALL_INFERIORS with all_non_exited_inferiors. * thread-iter.c: New file. * thread-iter.h: New file. * thread.c: Include "inline-frame.h". (thread_list): Delete. (clear_thread_inferior_resources): Call clear_inline_frame_state. (init_thread_list): Use all_threads_safe instead of ALL_THREADS_SAFE. Adjust to per-inferior thread lists. (new_thread): Adjust to per-inferior thread lists. (add_thread_silent): Pass inferior to find_thread_ptid. (thread_info::deletable): New, moved from the header. (delete_thread_1): Adjust to per-inferior thread lists. (find_thread_global_id): Use inf->threads(). (find_thread_ptid): Use find_inferior_ptid and pass inferior to find_thread_ptid. (find_thread_ptid(inferior*, ptid_t)): New overload. (iterate_over_threads): Use all_threads_safe. (any_thread_p): New. (thread_count): Use all_threads and std::distance. (live_threads_count): Use all_non_exited_threads and std::distance. (valid_global_thread_id): Use all_threads. (in_thread_list): Use find_thread_ptid. (first_thread_of_inferior): Adjust to per-inferior thread lists. (any_thread_of_inferior, any_live_thread_of_inferior): Use inf->non_exited_threads(). (prune_threads, delete_exited_threads): Use all_threads_safe. (thread_change_ptid): Pass inferior pointer to find_thread_ptid. (set_resumed, set_running): Use all_non_exited_threads. (is_thread_state, is_stopped, is_exited, is_running) (is_executing): Delete. (set_executing, set_stop_requested, finish_thread_state): Use all_non_exited_threads. (print_thread_info_1): Use all_inferiors and all_threads. (thread_apply_all_command): Use all_non_exited_threads. (thread_find_command): Use all_threads. (update_threads_executing): Use all_non_exited_threads. * tid-parse.c (parse_thread_id): Use inf->threads. * x86-bsd-nat.c (x86bsd_dr_set): Use inf->non_exited_threads ().
2018-11-22 17:09:14 +01:00
};
#endif /* !defined (INFERIOR_ITER_H) */