Re: [PATCH] Disable thread specific breakpoints when thread dies

[Andrew STUBBS <andrew.stubbs@st.com>]

Any opinions anybody?

Andrew Stubbs wrote:
> Andrew STUBBS wrote:
>> Now onto figuring out why it doesn't work....
> 
> The smoking gun seems to be here:
> 
> [From linux-thread-db.c]
> 
> static void
> detach_thread (ptid_t ptid, int verbose)
> {
>   struct thread_info *thread_info;
> 
>   if (verbose)
>     printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (ptid));
> 
>   /* Don't delete the thread now, because it still reports as active
>      until it has executed a few instructions after the event
>      breakpoint - if we deleted it now, "info threads" would cause us
>      to re-attach to it.  Just mark it as having had a TD_DEATH
>      event.  This means that we won't delete it from our thread list
>      until we notice that it's dead (via prune_threads), or until
>      something re-uses its thread ID.  */
>   thread_info = find_thread_pid (ptid);
>   gdb_assert (thread_info != NULL);
>   thread_info->private->dying = 1;
> }
> 
> 
> The attached patch fixes the problem, but I don't know if it does it the 
> best way.
> 
> What do you think?
> 
> Andrew Stubbs
> 
> 
> ------------------------------------------------------------------------
> 
> 2006-01-16  Amdrew Stubbs  <andrew.stubbs@st.com>
> 
> 	* gdbthread.h (prune_threads): Add prototype.
> 	* infrun.c (normal_stop): Call prune_threads().
> 	* thread.c (prune_threads): Remove 'static'.
> 
> Index: src/gdb/gdbthread.h
> ===================================================================
> --- src.orig/gdb/gdbthread.h	2006-01-16 16:08:57.000000000 +0000
> +++ src/gdb/gdbthread.h	2006-01-16 16:13:57.000000000 +0000
> @@ -80,6 +80,9 @@ extern struct thread_info *add_thread (p
>  /* Delete an existing thread list entry.  */
>  extern void delete_thread (ptid_t);
>  
> +/* Delete all dead threads from the list.  */
> +extern void prune_threads (void);
> +
>  /* Delete a step_resume_breakpoint from the thread database. */
>  extern void delete_step_resume_breakpoint (void *);
>  
> Index: src/gdb/infrun.c
> ===================================================================
> --- src.orig/gdb/infrun.c	2006-01-16 16:08:57.000000000 +0000
> +++ src/gdb/infrun.c	2006-01-16 16:13:57.000000000 +0000
> @@ -3037,6 +3037,9 @@ Further execution is probably impossible
>    if (stopped_by_random_signal)
>      disable_current_display ();
>  
> +  /* Delete any threads which have died.  */
> +  prune_threads ();
> +
>    /* Don't print a message if in the middle of doing a "step n"
>       operation for n > 1 */
>    if (step_multi && stop_step)
> Index: src/gdb/thread.c
> ===================================================================
> --- src.orig/gdb/thread.c	2006-01-16 16:08:57.000000000 +0000
> +++ src/gdb/thread.c	2006-01-16 16:13:57.000000000 +0000
> @@ -64,7 +64,6 @@ static void info_threads_command (char *
>  static void thread_apply_command (char *, int);
>  static void restore_current_thread (ptid_t);
>  static void switch_to_thread (ptid_t ptid);
> -static void prune_threads (void);
>  
>  void
>  delete_step_resume_breakpoint (void *arg)
> @@ -382,7 +381,7 @@ thread_alive (struct thread_info *tp)
>    return 1;
>  }
>  
> -static void
> +void
>  prune_threads (void)
>  {
>    struct thread_info *tp, *next;