Re: [PATCH 02/18] Remote all-stop-on-top-of-non-stop

[Yao Qi <qiyaoltc@gmail.com>]

Pedro Alves <palves@redhat.com> writes:

> @@ -2636,8 +2633,37 @@ attach_command_post_wait (char *args, int from_tty, int async_exec)
>    target_post_attach (ptid_get_pid (inferior_ptid));
>  
>    post_create_inferior (&current_target, from_tty);
> +}
> +
> +/* What to do after the first program stops after attaching.  */
> +enum attach_post_wait_mode
> +{
> +  /* Do nothing.  Leaves threads as they are.  */
> +  ATTACH_POST_WAIT_NOTHING,
> +
> +  /* Re-resume threads that are marked running.  */
> +  ATTACH_POST_WAIT_RESUME,
> +
> +  /* Stop all threads.  */
> +  ATTACH_POST_WAIT_STOP,
> +};
> +
> +/* Called after we've attached to a process and we've seen it stop for
> +   the first time.  If ASYNC_EXEC is true, re-resume threads that
> +   should be running.  Else if ATTACH, */
> +

Comments are not complete.

> +
> +  /* Now go over all threads that are stopped, and print their current
> +     frame.  If all-stop, then if there's a signalled thread, pick
> +     that as current.  */

Is it the code you described in the last paragraph of the commit log?

> +  ALL_NON_EXITED_THREADS (thread)
> +    {
> +      struct target_waitstatus *ws;
> +
> +      if (first == NULL)
> +	first = thread;
> +
> +      if (!non_stop)
> +	set_running (thread->ptid, 0);
> +      else if (thread->state != THREAD_STOPPED)
> +	continue;
> +
> +      ws = &thread->suspend.waitstatus;
> +
> +      if (selected == NULL
> +	  && thread->suspend.waitstatus_pending_p)
> +	selected = thread;
> +
> +      if (lowest == NULL || thread->num < lowest->num)
> +	lowest = thread;
> +
> +      if (non_stop)
> +	print_one_stopped_thread (thread);
> +    }
> +
> +  /* In all-stop, we only print the status of one thread, and leave
> +     others with their status pending.  */
> +  if (!non_stop)
> +    {
> +      thread = selected;
> +      if (thread == NULL)
> +	thread = lowest;
> +      if (thread == NULL)
> +	thread = first;

Looks lowest can't be NULL, so first isn't used.

> +
> +      print_one_stopped_thread (thread);
> +    }
> +
> +  /* For "info program".  */
> +  thread = inferior_thread ();
> +  if (thread->state == THREAD_STOPPED)
> +    set_last_target_status (inferior_ptid, thread->suspend.waitstatus);
>  }
>  
>  static void
> @@ -3826,7 +3942,7 @@ remote_start_remote (int from_tty, struct target_ops *target, int extended_p)

> @@ -12936,11 +13040,15 @@ remote_async (struct target_ops *ops, int enable)
>  	 event loop to process them.  */
>        if (!QUEUE_is_empty (stop_reply_p, stop_reply_queue))
>  	mark_async_event_handler (remote_async_inferior_event_token);
> +      if (target_is_non_stop_p ())
> +	mark_async_event_handler (rs->notif_state->get_pending_events_token);

I don't understand why do we need to mark the pending event token.
Previously, we only need to do so when GDB sees a notification.

>      }
>    else
>      {
>        serial_async (rs->remote_desc, NULL, NULL);
>        clear_async_event_handler (remote_async_inferior_event_token);
> +      if (target_is_non_stop_p ())
> +	clear_async_event_handler (rs->notif_state->get_pending_events_token);
>      }
>  }
>  

-- 
Yao (齐尧)