Add "executing" property to threads.

* inferior.h (target_executing): Delete.
	* gdbthread.h (struct thread_info): Add executing_ field.
	(set_executing, is_executing): New.
	* thread.c (main_thread_executing): New.
	(init_thread_list): Clear it and also main_thread_running.
	(is_running): Return false if target has no execution.
	(any_running, is_executing, set_executing): New.

	* top.c: Include "gdbthread.h".
	(target_executing): Delete.
	(execute_command): Replace target_executing check by any_running.
	* event-top.c: Include "gdbthread.h".
	(display_gdb_prompt, command_handler): Replace target_executing by
	is_running.
	* inf-loop.c: Include "gdbthread.h".  Don't mark as not executing
	here.  Replace target_executing by is_running.
	* infrun.c (handle_inferior_event): Mark all threads as
	not-executing.
	* linux-nat.c (linux_nat_resume): Don't mark thread as executing
	here.
	* stack.c (get_selected_block): Return null if inferior is
	executing.
	* target.c (target_resume): Mark resumed ptid as executing.
	* breakpoint.c (until_break_command): Replace target_executing
	check by is_executing.
	* remote.c (remote_async_resume): Don't mark inferior as executing
	here.
	* mi/mi-interp.c (mi_cmd_interpreter_exec): Replace target_executing
	by any_running.

	* mi/mi-main.c (mi_cmd_exec_interrupt, mi_cmd_execute)
	(mi_execute_async_cli_command): Replace target_executing by
	is_running.

	* frame.c (get_current_frame): Error out if the current thread is
	executing.
	(has_stack_frames): New.
	(get_selected_frame, deprecated_safe_get_selected_frame): Check
	has_stack_frames.

	* Makefile.in (event-top.o, frame.o, inf-loop.o, top.o): Depend on
	$(gdbthread_h).

gdb/ChangeLog

@@ -1,3 +1,50 @@
+2008-07-09  Pedro Alves  <pedro@codesourcery.com>
+
+	Add "executing" property to threads.
+
+	* inferior.h (target_executing): Delete.
+	* gdbthread.h (struct thread_info): Add executing_ field.
+	(set_executing, is_executing): New.
+	* thread.c (main_thread_executing): New.
+	(init_thread_list): Clear it and also main_thread_running.
+	(is_running): Return false if target has no execution.
+	(any_running, is_executing, set_executing): New.
+
+	* top.c: Include "gdbthread.h".
+	(target_executing): Delete.
+	(execute_command): Replace target_executing check by any_running.
+	* event-top.c: Include "gdbthread.h".
+	(display_gdb_prompt, command_handler): Replace target_executing by
+	is_running.
+	* inf-loop.c: Include "gdbthread.h".  Don't mark as not executing
+	here.  Replace target_executing by is_running.
+	* infrun.c (handle_inferior_event): Mark all threads as
+	not-executing.
+	* linux-nat.c (linux_nat_resume): Don't mark thread as executing
+	here.
+	* stack.c (get_selected_block): Return null if inferior is
+	executing.
+	* target.c (target_resume): Mark resumed ptid as executing.
+	* breakpoint.c (until_break_command): Replace target_executing
+	check by is_executing.
+	* remote.c (remote_async_resume): Don't mark inferior as executing
+	here.
+	* mi/mi-interp.c (mi_cmd_interpreter_exec): Replace target_executing
+	by any_running.
+	
+	* mi/mi-main.c (mi_cmd_exec_interrupt, mi_cmd_execute)
+	(mi_execute_async_cli_command): Replace target_executing by
+	is_running.
+
+	* frame.c (get_current_frame): Error out if the current thread is
+	executing.
+	(has_stack_frames): New.
+	(get_selected_frame, deprecated_safe_get_selected_frame): Check
+	has_stack_frames.
+	
+	* Makefile.in (event-top.o, frame.o, inf-loop.o, top.o): Depend on
+	$(gdbthread_h).
+
 2008-07-09  Pedro Alves  <pedro@codesourcery.com>
 
 	* symfile.c (load_command): Reopen the exec file and reread

gdb/Makefile.in

@@ -2106,7 +2106,7 @@ event-loop.o: event-loop.c $(defs_h) $(event_loop_h) $(event_top_h) \
 event-top.o: event-top.c $(defs_h) $(top_h) $(inferior_h) $(target_h) \
 	$(terminal_h) $(event_loop_h) $(event_top_h) $(interps_h) \
 	$(exceptions_h) $(cli_script_h) $(gdbcmd_h) $(readline_h) \
-	$(readline_history_h) $(main_h)
+	$(readline_history_h) $(main_h) $(gdbthread_h)
 exceptions.o: exceptions.c $(defs_h) $(exceptions_h) $(breakpoint_h) \
 	$(target_h) $(inferior_h) $(annotate_h) $(ui_out_h) $(gdb_assert_h) \
 	$(gdb_string_h) $(serial_h)
@@ -2141,7 +2141,8 @@ frame.o: frame.c $(defs_h) $(frame_h) $(target_h) $(value_h) $(inferior_h) \
 	$(regcache_h) $(gdb_assert_h) $(gdb_string_h) $(user_regs_h) \
 	$(gdb_obstack_h) $(dummy_frame_h) $(sentinel_frame_h) $(gdbcore_h) \
 	$(annotate_h) $(language_h) $(frame_unwind_h) $(frame_base_h) \
-	$(command_h) $(gdbcmd_h) $(observer_h) $(objfiles_h) $(exceptions_h)
+	$(command_h) $(gdbcmd_h) $(observer_h) $(objfiles_h) $(exceptions_h) \
+	$(gdbthread_h)
 frame-unwind.o: frame-unwind.c $(defs_h) $(frame_h) $(frame_unwind_h) \
 	$(gdb_assert_h) $(dummy_frame_h) $(gdb_obstack_h) $(value_h) \
 	$(regcache_h)
@@ -2322,7 +2323,7 @@ infcmd.o: infcmd.c $(defs_h) $(gdb_string_h) $(symtab_h) $(gdbtypes_h) \
 	$(user_regs_h) $(exceptions_h) $(cli_decode_h) $(gdbthread_h)
 inf-loop.o: inf-loop.c $(defs_h) $(inferior_h) $(target_h) $(event_loop_h) \
 	$(event_top_h) $(inf_loop_h) $(remote_h) $(exceptions_h) \
-	$(language_h)
+	$(language_h) $(gdbthread_h)
 inflow.o: inflow.c $(defs_h) $(frame_h) $(inferior_h) $(command_h) \
 	$(serial_h) $(terminal_h) $(target_h) $(gdbthread_h) $(gdb_string_h) \
 	$(inflow_h) $(gdb_select_h)
@@ -2928,7 +2929,7 @@ top.o: top.c $(defs_h) $(gdbcmd_h) $(call_cmds_h) $(cli_cmds_h) \
 	$(annotate_h) $(completer_h) $(top_h) $(version_h) $(serial_h) \
 	$(doublest_h) $(gdb_assert_h) $(readline_h) $(readline_history_h) \
 	$(event_top_h) $(gdb_string_h) $(gdb_stat_h) $(ui_out_h) \
-	$(cli_out_h) $(main_h) $(event_loop_h)
+	$(cli_out_h) $(main_h) $(event_loop_h) $(gdbthread_h)
 tracepoint.o: tracepoint.c $(defs_h) $(symtab_h) $(frame_h) $(gdbtypes_h) \
 	$(expression_h) $(gdbcmd_h) $(value_h) $(target_h) $(language_h) \
 	$(gdb_string_h) $(inferior_h) $(tracepoint_h) $(remote_h) \

gdb/breakpoint.c

@@ -6229,7 +6229,7 @@ until_break_command (char *arg, int from_tty, int anywhere)
      deleted when the target stops.  Otherwise, we're already stopped and
      delete breakpoints via cleanup chain.  */
 
-  if (target_can_async_p () && target_executing)
+  if (target_can_async_p () && is_running (inferior_ptid))
     {
       arg1 =
 	(struct continuation_arg *) xmalloc (sizeof (struct continuation_arg));

gdb/event-top.c

@@ -32,6 +32,7 @@
 #include "exceptions.h"
 #include "cli/cli-script.h"     /* for reset_command_nest_depth */
 #include "main.h"
+#include "gdbthread.h"
 
 /* For dont_repeat() */
 #include "gdbcmd.h"
@@ -268,7 +269,7 @@ display_gdb_prompt (char *new_prompt)
   if (!current_interp_display_prompt_p ())
     return;
 
-  if (target_executing && sync_execution)
+  if (sync_execution && is_running (inferior_ptid))
     {
       /* This is to trick readline into not trying to display the
          prompt.  Even though we display the prompt using this
@@ -516,7 +517,7 @@ command_handler (char *command)
   /* Do any commands attached to breakpoint we stopped at. Only if we
      are always running synchronously. Or if we have just executed a
      command that doesn't start the target. */
-  if (!target_can_async_p () || !target_executing)
+  if (!target_can_async_p () || !is_running (inferior_ptid))
     {
       bpstat_do_actions (&stop_bpstat);
       do_cleanups (old_chain);

gdb/frame.c

@@ -40,6 +40,7 @@
 #include "observer.h"
 #include "objfiles.h"
 #include "exceptions.h"
+#include "gdbthread.h"
 
 static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame);
 
@@ -930,6 +931,9 @@ get_current_frame (void)
     error (_("No stack."));
   if (!target_has_memory)
     error (_("No memory."));
+  if (is_executing (inferior_ptid))
+    error (_("Target is executing."));
+
   if (current_frame == NULL)
     {
       struct frame_info *sentinel_frame =
@@ -950,6 +954,20 @@ get_current_frame (void)
 
 static struct frame_info *selected_frame;
 
+static int
+has_stack_frames (void)
+{
+  if (!target_has_registers || !target_has_stack || !target_has_memory)
+    return 0;
+
+  /* If the current thread is executing, don't try to read from
+     it.  */
+  if (is_executing (inferior_ptid))
+    return 0;
+
+  return 1;
+}
+
 /* Return the selected frame.  Always non-NULL (unless there isn't an
    inferior sufficient for creating a frame) in which case an error is
    thrown.  */
@@ -959,9 +977,7 @@ get_selected_frame (const char *message)
 {
   if (selected_frame == NULL)
     {
-      if (message != NULL && (!target_has_registers
+      if (message != NULL && !has_stack_frames ())
-			      || !target_has_stack
-			      || !target_has_memory))
 	error (("%s"), message);
       /* Hey!  Don't trust this.  It should really be re-finding the
 	 last selected frame of the currently selected thread.  This,
@@ -980,7 +996,7 @@ get_selected_frame (const char *message)
 struct frame_info *
 deprecated_safe_get_selected_frame (void)
 {
-  if (!target_has_registers || !target_has_stack || !target_has_memory)
+  if (!has_stack_frames ())
     return NULL;
   return get_selected_frame (NULL);
 }

gdb/gdbthread.h

@@ -41,6 +41,25 @@ struct thread_info
 				    In fact, this may be overloaded with 
 				    kernel thread id, etc.  */
   int num;			/* Convenient handle (GDB thread id) */
+
+  /* Non-zero means the thread is executing.  Note: this is different
+     from saying that there is an active target and we are stopped at
+     a breakpoint, for instance.  This is a real indicator whether the
+     thread is off and running.  */
+  /* This field is internal to thread.c.  Never access it directly,
+     use is_executing instead.  */
+  int executing_;
+
+  /* Frontend view of the running state.  Note that this is different
+     from EXECUTING.  When the thread is stopped internally while
+     handling an internal event, like a software single-step
+     breakpoint, executing will be false, but running will still be
+     true.  As a possible future extension, this could turn into
+     enum { stopped, stepping, finishing, until(ling), ... }  */
+  /* This field is internal to thread.c.  Never access it directly,
+     use is_running instead.  */
+  int running_;
+
   /* State from wait_for_inferior */
   CORE_ADDR prev_pc;
   struct breakpoint *step_resume_breakpoint;
@@ -63,10 +82,6 @@ struct thread_info
      when we finally do stop stepping.  */
   bpstat stepping_through_solib_catchpoints;
 
-  /* This field is internal for thread.c.  Never access it directly,
-     use is_running instead.  */
-  int running_;
-
   /* Private data used by the target vector implementation.  */
   struct private_thread_info *private;
 };
@@ -161,9 +176,19 @@ extern void switch_to_thread (ptid_t ptid);
    If PIDGET (PTID) is -1, marks all threads.  */
 extern void set_running (ptid_t ptid, int running);
 
-/* Reports if thread PTID is know to be running right now.  */
+/* Reports if thread PTID is known to be running right now.  */
 extern int is_running (ptid_t ptid);
 
+/* Reports if any thread is known to be running right now.  */
+extern int any_running (void);
+
+/* Marks thread PTID as executing, or as stopped.
+   If PIDGET (PTID) is -1, marks all threads.  */
+extern void set_executing (ptid_t ptid, int executing);
+
+/* Reports if thread PTID is executing.  */
+extern int is_executing (ptid_t ptid);
+
 /* Commands with a prefix of `thread'.  */
 extern struct cmd_list_element *thread_cmd_list;
 

gdb/inf-loop.c

@@ -26,6 +26,7 @@
 #include "remote.h"
 #include "exceptions.h"
 #include "language.h"
+#include "gdbthread.h"
 
 static int fetch_inferior_event_wrapper (gdb_client_data client_data);
 
@@ -72,14 +73,6 @@ inferior_event_handler (enum inferior_event_type event_type,
       break;
 
     case INF_EXEC_COMPLETE:
-
-      /* This is the first thing to do -- so that continuations know that
-	 the target is stopped.  For example, command_line_handler_continuation
-	 will run breakpoint commands, and if we think that the target is
-	 running, we'll refuse to execute most commands.  MI continuation
-	 presently uses target_executing to either print or not print *stopped.  */
-      target_executing = 0;
-
       /* Unregister the inferior from the event loop. This is done so that
 	 when the inferior is not running we don't get distracted by
 	 spurious inferior output.  */
@@ -121,8 +114,8 @@ inferior_event_handler (enum inferior_event_type event_type,
 
       /* If no breakpoint command resumed the inferior, prepare for
 	 interaction with the user.  */
-      if (!target_executing)
+      if (!is_running (inferior_ptid))
-	{              
+	{
 	  if (was_sync)
 	    {
 	      display_gdb_prompt (0);

gdb/inferior.h

@@ -111,12 +111,6 @@ extern const char *get_inferior_io_terminal (void);
 
 extern ptid_t inferior_ptid;
 
-/* Is the inferior running right now, as a result of a 'run&',
-   'continue&' etc command? This is used in asycn gdb to determine
-   whether a command that the user enters while the target is running
-   is allowed or not. */
-extern int target_executing;
-
 /* Are we simulating synchronous execution? This is used in async gdb
    to implement the 'run', 'continue' etc commands, which will not
    redisplay the prompt until the execution is actually over. */

gdb/infrun.c

@@ -1771,6 +1771,11 @@ handle_inferior_event (struct execution_control_state *ecs)
       && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED && ecs->new_thread_event)
     add_thread (ecs->ptid);
 
+  /* Mark all threads as not-executing.  In non-stop, this should be
+     adjusted to only mark ecs->ptid.  */
+  if (ecs->ws.kind != TARGET_WAITKIND_IGNORE)
+    set_executing (pid_to_ptid (-1), 0);
+
   switch (ecs->ws.kind)
     {
     case TARGET_WAITKIND_LOADED:

gdb/linux-nat.c

@@ -1624,10 +1624,7 @@ linux_nat_resume (ptid_t ptid, int step, enum target_signal signo)
 			signo ? strsignal (signo) : "0");
 
   if (target_can_async_p ())
-    {
+    target_async (inferior_event_handler, 0);
-      target_executing = 1;
-      target_async (inferior_event_handler, 0);
-    }
 }
 
 /* Issue kill to specified lwp.  */

gdb/mi/mi-main.c

@@ -175,8 +175,8 @@ mi_cmd_exec_continue (char *command, char **argv, int argc)
 void
 mi_cmd_exec_interrupt (char *command, char **argv, int argc)
 {
-  if (!target_executing)
+  if (!is_running (inferior_ptid))
-    error ("mi_cmd_exec_interrupt: Inferior not executing.");
+    error ("mi_cmd_exec_interrupt: Inferior not running.");
 
   interrupt_target_command (NULL, 0);
 }
@@ -1059,7 +1059,7 @@ mi_cmd_execute (struct mi_parse *parse)
 
   if (parse->cmd->argv_func != NULL)
     {
-      if (target_executing)
+      if (is_running (inferior_ptid))
 	{
 	  if (strcmp (parse->command, "exec-interrupt"))
 	    {
@@ -1144,7 +1144,7 @@ mi_execute_async_cli_command (char *cli_command, char **argv, int argc)
   if (target_can_async_p ())
     {
       /* If we're not executing, an exception should have been throw.  */
-      gdb_assert (target_executing);
+      gdb_assert (is_running (inferior_ptid));
       do_cleanups (old_cleanups);
     }
   else

gdb/remote.c

@@ -3232,13 +3232,6 @@ remote_resume (ptid_t ptid, int step, enum target_signal siggnal)
      NOT asynchronously.  */
   if (target_can_async_p ())
     target_async (inferior_event_handler, 0);
-  /* Tell the world that the target is now executing.  */
-  /* FIXME: cagney/1999-09-23: Is it the targets responsibility to set
-     this?  Instead, should the client of target just assume (for
-     async targets) that the target is going to start executing?  Is
-     this information already found in the continuation block?  */
-  if (target_is_async_p ())
-    target_executing = 1;
 }
 
 

gdb/stack.c

@@ -43,6 +43,7 @@
 #include "regcache.h"
 #include "solib.h"
 #include "valprint.h"
+#include "gdbthread.h"
 
 #include "gdb_assert.h"
 #include <ctype.h>
@@ -1643,6 +1644,9 @@ get_selected_block (CORE_ADDR *addr_in_block)
   if (!target_has_stack)
     return 0;
 
+  if (is_executing (inferior_ptid))
+    return 0;
+
   return get_frame_block (get_selected_frame (NULL), addr_in_block);
 }
 

gdb/target.c

@@ -1787,8 +1787,8 @@ target_resume (ptid_t ptid, int step, enum target_signal signal)
 {
   dcache_invalidate (target_dcache);
   (*current_target.to_resume) (ptid, step, signal);
+  set_executing (ptid, 1);
   set_running (ptid, 1);
-
 }
 /* Look through the list of possible targets for a target that can
    follow forks.  */

gdb/thread.c

@@ -63,6 +63,9 @@ static void thread_apply_command (char *, int);
 static void restore_current_thread (ptid_t);
 static void prune_threads (void);
 
+static int main_thread_running = 0;
+static int main_thread_executing = 0;
+
 void
 delete_step_resume_breakpoint (void *arg)
 {
@@ -104,6 +107,9 @@ init_thread_list (void)
   struct thread_info *tp, *tpnext;
 
   highest_thread_num = 0;
+  main_thread_running = 0;
+  main_thread_executing = 0;
+
   if (!thread_list)
     return;
 
@@ -441,8 +447,6 @@ prune_threads (void)
     }
 }
 
-static int main_thread_running = 0;
-
 void
 set_running (ptid_t ptid, int running)
 {
@@ -494,6 +498,9 @@ is_running (ptid_t ptid)
 {
   struct thread_info *tp;
 
+  if (!target_has_execution)
+    return 0;
+
   if (!thread_list)
     return main_thread_running;
 
@@ -502,6 +509,67 @@ is_running (ptid_t ptid)
   return tp->running_;  
 }
 
+int
+any_running (void)
+{
+  struct thread_info *tp;
+
+  if (!target_has_execution)
+    return 0;
+
+  if (!thread_list)
+    return main_thread_running;
+
+  for (tp = thread_list; tp; tp = tp->next)
+    if (tp->running_)
+      return 1;
+
+  return 0;
+}
+
+int
+is_executing (ptid_t ptid)
+{
+  struct thread_info *tp;
+
+  if (!target_has_execution)
+    return 0;
+
+  if (!thread_list)
+    return main_thread_executing;
+
+  tp = find_thread_pid (ptid);
+  gdb_assert (tp);
+  return tp->executing_;
+}
+
+void
+set_executing (ptid_t ptid, int executing)
+{
+  struct thread_info *tp;
+
+  if (!thread_list)
+    {
+      /* This target does not add the main thread to the thread list.
+	 Use a global flag to indicate that the thread is
+	 executing.  */
+      main_thread_executing = executing;
+      return;
+    }
+
+  if (PIDGET (ptid) == -1)
+    {
+      for (tp = thread_list; tp; tp = tp->next)
+	tp->executing_ = executing;
+    }
+  else
+    {
+      tp = find_thread_pid (ptid);
+      gdb_assert (tp);
+      tp->executing_ = executing;
+    }
+}
+
 /* Prints the list of threads and their details on UIOUT.
    This is a version of 'info_thread_command' suitable for
    use from MI.  

gdb/top.c

@@ -46,6 +46,7 @@
 #include "gdb_assert.h"
 #include "main.h"
 #include "event-loop.h"
+#include "gdbthread.h"
 
 /* readline include files */
 #include "readline/readline.h"
@@ -181,12 +182,6 @@ int remote_timeout = 2;
 
 int remote_debug = 0;
 
-/* Non-zero means the target is running. Note: this is different from
-   saying that there is an active target and we are stopped at a
-   breakpoint, for instance. This is a real indicator whether the
-   target is off and running, which gdb is doing something else. */
-int target_executing = 0;
-
 /* Sbrk location on entry to main.  Used for statistics only.  */
 #ifdef HAVE_SBRK
 char *lim_at_start;
@@ -422,7 +417,9 @@ execute_command (char *p, int from_tty)
 
       /* If the target is running, we allow only a limited set of
          commands. */
-      if (target_can_async_p () && target_executing && !get_cmd_async_ok (c))
+      if (target_can_async_p ()
+	  && any_running ()
+	  && !get_cmd_async_ok (c))
 	error (_("Cannot execute this command while the target is running."));
 
       /* Pass null arg rather than an empty one.  */
@@ -486,7 +483,7 @@ execute_command (char *p, int from_tty)
   /* FIXME:  This should be cacheing the frame and only running when
      the frame changes.  */
 
-  if (!target_executing && target_has_stack)
+  if (target_has_stack && !is_running (inferior_ptid))
     {
       flang = get_frame_language ();
       if (!warned