2008-06-28  Pedro Alves  <pedro@codesourcery.com>

	* linux-nat.c (enum sigchld_state): New.
	(linux_nat_async_events_state): Renamed from
	linux_nat_async_events_enabled.
	(linux_nat_event_pipe_push, my_waitpid): Adjust.
	(sigchld_default_action): New.
	(lin_lwp_attach_lwp): Adjust.  Call linux_nat_async_events
	unconditionally.
	(linux_nat_create_inferior): Set events state to sigchld_default
	state.
	(linux_nat_resume): Adjust.
	(linux_nat_wait): Call linux_nat_async_events unconditionally.
	(sigchld_handler): Adjust.
	(linux_nat_async_mask): Don't set SIGCHLD actions here.
	(get_pending_events): Adjust.
	(linux_nat_async_events): Rewrite to handle enum sigchld_state
	instead of a boolean.
	(linux_nat_async): Adjust.
	(_initialize_linux_nat): Capture default SIGCHLD action into
	sigchld_default_action.

gdb/testsuite/
2008-06-28  Pedro Alves  <pedro@codesourcery.com>

	* gdb.base/sigchld.c, gdb.base/sigchld.exp: New test.
This commit is contained in:
Pedro Alves 2008-06-28 11:15:34 +00:00
parent 0f8d4a2f6e
commit 84e46146f7
5 changed files with 209 additions and 57 deletions

View File

@ -1,3 +1,25 @@
2008-06-28 Pedro Alves <pedro@codesourcery.com>
* linux-nat.c (enum sigchld_state): New.
(linux_nat_async_events_state): Renamed from
linux_nat_async_events_enabled.
(linux_nat_event_pipe_push, my_waitpid): Adjust.
(sigchld_default_action): New.
(lin_lwp_attach_lwp): Adjust. Call linux_nat_async_events
unconditionally.
(linux_nat_create_inferior): Set events state to sigchld_default
state.
(linux_nat_resume): Adjust.
(linux_nat_wait): Call linux_nat_async_events unconditionally.
(sigchld_handler): Adjust.
(linux_nat_async_mask): Don't set SIGCHLD actions here.
(get_pending_events): Adjust.
(linux_nat_async_events): Rewrite to handle enum sigchld_state
instead of a boolean.
(linux_nat_async): Adjust.
(_initialize_linux_nat): Capture default SIGCHLD action into
sigchld_default_action.
2008-06-28 Vladimir Prus <vladimir@codesourcery.com>
* breakpoint.c (moribund_locations): New.

View File

@ -256,11 +256,24 @@ static int linux_nat_event_pipe[2] = { -1, -1 };
/* Number of queued events in the pipe. */
static volatile int linux_nat_num_queued_events;
/* If async mode is on, true if we're listening for events; false if
target events are blocked. */
static int linux_nat_async_events_enabled;
/* The possible SIGCHLD handling states. */
static int linux_nat_async_events (int enable);
enum sigchld_state
{
/* SIGCHLD disabled, with action set to sigchld_handler, for the
sigsuspend in linux_nat_wait. */
sigchld_sync,
/* SIGCHLD enabled, with action set to async_sigchld_handler. */
sigchld_async,
/* Set SIGCHLD to default action. Used while creating an
inferior. */
sigchld_default
};
/* The current SIGCHLD handling state. */
static enum sigchld_state linux_nat_async_events_state;
static enum sigchld_state linux_nat_async_events (enum sigchld_state enable);
static void pipe_to_local_event_queue (void);
static void local_event_queue_to_pipe (void);
static void linux_nat_event_pipe_push (int pid, int status, int options);
@ -294,8 +307,8 @@ queued_waitpid (int pid, int *status, int flags)
if (debug_linux_nat_async)
fprintf_unfiltered (gdb_stdlog,
"\
QWPID: linux_nat_async_events_enabled(%d), linux_nat_num_queued_events(%d)\n",
linux_nat_async_events_enabled,
QWPID: linux_nat_async_events_state(%d), linux_nat_num_queued_events(%d)\n",
linux_nat_async_events_state,
linux_nat_num_queued_events);
if (flags & __WALL)
@ -441,7 +454,7 @@ my_waitpid (int pid, int *status, int flags)
int ret;
/* There should be no concurrent calls to waitpid. */
gdb_assert (!linux_nat_async_events_enabled);
gdb_assert (linux_nat_async_events_state == sigchld_sync);
ret = queued_waitpid (pid, status, flags);
if (ret != -1)
@ -862,6 +875,9 @@ struct sigaction sync_sigchld_action;
/* SIGCHLD action for asynchronous mode. */
static struct sigaction async_sigchld_action;
/* SIGCHLD default action, to pass to new inferiors. */
static struct sigaction sigchld_default_action;
/* Prototypes for local functions. */
@ -1185,12 +1201,11 @@ int
lin_lwp_attach_lwp (ptid_t ptid)
{
struct lwp_info *lp;
int async_events_were_enabled = 0;
enum sigchld_state async_events_original_state;
gdb_assert (is_lwp (ptid));
if (target_can_async_p ())
async_events_were_enabled = linux_nat_async_events (0);
async_events_original_state = linux_nat_async_events (sigchld_sync);
lp = find_lwp_pid (ptid);
@ -1255,9 +1270,7 @@ lin_lwp_attach_lwp (ptid_t ptid)
lp->stopped = 1;
}
if (async_events_were_enabled)
linux_nat_async_events (1);
linux_nat_async_events (async_events_original_state);
return 0;
}
@ -1271,6 +1284,8 @@ linux_nat_create_inferior (char *exec_file, char *allargs, char **env,
we have to mask the async mode. */
if (target_can_async_p ())
/* Mask async mode. Creating a child requires a loop calling
wait_for_inferior currently. */
saved_async = linux_nat_async_mask (0);
else
{
@ -1281,6 +1296,12 @@ linux_nat_create_inferior (char *exec_file, char *allargs, char **env,
sigdelset (&suspend_mask, SIGCHLD);
}
/* Set SIGCHLD to the default action, until after execing the child,
since the inferior inherits the superior's signal mask. It will
be blocked again in linux_nat_wait, which is only reached after
the inferior execing. */
linux_nat_async_events (sigchld_default);
linux_ops->to_create_inferior (exec_file, allargs, env, from_tty);
if (saved_async)
@ -1512,7 +1533,7 @@ linux_nat_resume (ptid_t ptid, int step, enum target_signal signo)
if (target_can_async_p ())
/* Block events while we're here. */
linux_nat_async_events (0);
linux_nat_async_events (sigchld_sync);
/* A specific PTID means `step only this process id'. */
resume_all = (PIDGET (ptid) == -1);
@ -2574,9 +2595,8 @@ linux_nat_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
sigemptyset (&flush_mask);
if (target_can_async_p ())
/* Block events while we're here. */
target_async (NULL, 0);
linux_nat_async_events (sigchld_sync);
retry:
@ -3035,7 +3055,7 @@ static void
sigchld_handler (int signo)
{
if (linux_nat_async_enabled
&& linux_nat_async_events_enabled
&& linux_nat_async_events_state != sigchld_sync
&& signo == SIGCHLD)
/* It is *always* a bug to hit this. */
internal_error (__FILE__, __LINE__,
@ -3894,15 +3914,9 @@ linux_nat_async_mask (int mask)
{
linux_nat_async (NULL, 0);
linux_nat_async_mask_value = mask;
/* We're in sync mode. Make sure SIGCHLD isn't handled by
async_sigchld_handler when we come out of sigsuspend in
linux_nat_wait. */
sigaction (SIGCHLD, &sync_sigchld_action, NULL);
}
else
{
/* Restore the async handler. */
sigaction (SIGCHLD, &async_sigchld_action, NULL);
linux_nat_async_mask_value = mask;
linux_nat_async (inferior_event_handler, 0);
}
@ -3960,7 +3974,8 @@ get_pending_events (void)
{
int status, options, pid;
if (!linux_nat_async_enabled || !linux_nat_async_events_enabled)
if (!linux_nat_async_enabled
|| linux_nat_async_events_state != sigchld_async)
internal_error (__FILE__, __LINE__,
"get_pending_events called with async masked");
@ -4014,45 +4029,76 @@ async_sigchld_handler (int signo)
get_pending_events ();
}
/* Enable or disable async SIGCHLD handling. */
/* Set SIGCHLD handling state to STATE. Returns previous state. */
static int
linux_nat_async_events (int enable)
static enum sigchld_state
linux_nat_async_events (enum sigchld_state state)
{
int current_state = linux_nat_async_events_enabled;
enum sigchld_state current_state = linux_nat_async_events_state;
if (debug_linux_nat_async)
fprintf_unfiltered (gdb_stdlog,
"LNAE: enable(%d): linux_nat_async_events_enabled(%d), "
"LNAE: state(%d): linux_nat_async_events_state(%d), "
"linux_nat_num_queued_events(%d)\n",
enable, linux_nat_async_events_enabled,
state, linux_nat_async_events_state,
linux_nat_num_queued_events);
if (current_state != enable)
if (current_state != state)
{
sigset_t mask;
sigemptyset (&mask);
sigaddset (&mask, SIGCHLD);
if (enable)
{
/* Unblock target events. */
linux_nat_async_events_enabled = 1;
local_event_queue_to_pipe ();
/* While in masked async, we may have not collected all the
pending events. Get them out now. */
get_pending_events ();
sigprocmask (SIG_UNBLOCK, &mask, NULL);
}
else
/* Always block before changing state. */
sigprocmask (SIG_BLOCK, &mask, NULL);
/* Set new state. */
linux_nat_async_events_state = state;
switch (state)
{
case sigchld_sync:
{
/* Block target events. */
sigprocmask (SIG_BLOCK, &mask, NULL);
linux_nat_async_events_enabled = 0;
sigaction (SIGCHLD, &sync_sigchld_action, NULL);
/* Get events out of queue, and make them available to
queued_waitpid / my_waitpid. */
pipe_to_local_event_queue ();
}
break;
case sigchld_async:
{
/* Unblock target events for async mode. */
sigprocmask (SIG_BLOCK, &mask, NULL);
/* Put events we already waited on, in the pipe first, so
events are FIFO. */
local_event_queue_to_pipe ();
/* While in masked async, we may have not collected all
the pending events. Get them out now. */
get_pending_events ();
/* Let'em come. */
sigaction (SIGCHLD, &async_sigchld_action, NULL);
sigprocmask (SIG_UNBLOCK, &mask, NULL);
}
break;
case sigchld_default:
{
/* SIGCHLD default mode. */
sigaction (SIGCHLD, &sigchld_default_action, NULL);
/* Get events out of queue, and make them available to
queued_waitpid / my_waitpid. */
pipe_to_local_event_queue ();
/* Unblock SIGCHLD. */
sigprocmask (SIG_UNBLOCK, &mask, NULL);
}
break;
}
}
return current_state;
@ -4143,14 +4189,14 @@ linux_nat_async (void (*callback) (enum inferior_event_type event_type,
add_file_handler (linux_nat_event_pipe[0],
linux_nat_async_file_handler, NULL);
linux_nat_async_events (1);
linux_nat_async_events (sigchld_async);
}
else
{
async_client_callback = callback;
async_client_context = context;
linux_nat_async_events (0);
linux_nat_async_events (sigchld_sync);
delete_file_handler (linux_nat_event_pipe[0]);
}
return;
@ -4166,21 +4212,15 @@ linux_nat_set_async_mode (int on)
if (on)
{
gdb_assert (waitpid_queue == NULL);
sigaction (SIGCHLD, &async_sigchld_action, NULL);
if (pipe (linux_nat_event_pipe) == -1)
internal_error (__FILE__, __LINE__,
"creating event pipe failed.");
fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
}
else
{
sigaction (SIGCHLD, &sync_sigchld_action, NULL);
drain_queued_events (-1);
linux_nat_num_queued_events = 0;
close (linux_nat_event_pipe[0]);
close (linux_nat_event_pipe[1]);
@ -4297,6 +4337,10 @@ Tells gdb whether to control the GNU/Linux inferior in asynchronous mode."),
&maintenance_set_cmdlist,
&maintenance_show_cmdlist);
/* Get the default SIGCHLD action. Used while forking an inferior
(see linux_nat_create_inferior/linux_nat_async_events). */
sigaction (SIGCHLD, NULL, &sigchld_default_action);
/* Block SIGCHLD by default. Doing this early prevents it getting
unblocked if an exception is thrown due to an error while the
inferior is starting (sigsetjmp/siglongjmp). */

View File

@ -1,3 +1,7 @@
2008-06-28 Pedro Alves <pedro@codesourcery.com>
* gdb.base/sigchld.c, gdb.base/sigchld.exp: New test.
2008-06-28 Vladimir Prus <vladimir@codesourcery.com>
* lib/mi-support.exp (mi_send_resuming_command_raw): Report pass.

View File

@ -0,0 +1,37 @@
/* This testcase is part of GDB, the GNU debugger.
Copyright 2008 Free Software Foundation, Inc.
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/>.
*/
/* Check that GDB isn't messing the SIGCHLD mask while creating an
inferior. */
#include <signal.h>
#include <stdlib.h>
int
main ()
{
sigset_t mask;
sigemptyset (&mask);
sigprocmask (SIG_BLOCK, NULL, &mask);
if (!sigismember (&mask, SIGCHLD))
return 0; /* good, not blocked */
else
return 1; /* bad, blocked */
}

View File

@ -0,0 +1,45 @@
# Copyright (C) 2008 Free Software Foundation, Inc.
# 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/>.
# Check that GDB isn't messing the SIGCHLD mask while creating an
# inferior.
if [target_info exists gdb,nosignals] {
verbose "Skipping sigchld.exp because of nosignals."
continue
}
set testfile "sigchld"
set srcfile ${testfile}.c
set binfile ${objdir}/${subdir}/${testfile}
if {[gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
return -1
}
gdb_exit
gdb_start
gdb_reinitialize_dir $srcdir/$subdir
gdb_load ${binfile}
runto_main
gdb_test "b [gdb_get_line_number "good, not blocked"]" \
".*Breakpoint .*sigchld.*" "set breakpoint at success exit"
gdb_test "b [gdb_get_line_number "bad, blocked"]" \
".*Breakpoint .*sigchld.*" "set breakpoint at failure exit"
gdb_test "continue" ".*good, not blocked.*" "SIGCHLD blocked in inferior"