Move pending_event to remote_notif_state.

This patch moves pending_event to remote_notif_state.  All pending
events are destroyed in remote_notif_state_xfree.  However,
discard_pending_stop_replies release pending event too, so the pending
event of stop notification is released twice, we need some refactor
here.  We add a new function discard_pending_stop_replies_in_queue
which only discard events in stop_reply_queue, and let
remote_notif_state_xfree release pending event for all notif_client.

After this change, discard_pending_stop_replies is only attached to
ifnerior_exit observer, so the INF can't be NULL any more.  The
NULL checking is removed too.

gdb:

2013-10-04  Yao Qi  <yao@codesourcery.com>

	* remote-notif.h (REMOTE_NOTIF_ID): New enum.
	(struct notif_client) <pending_event>: Moved
	to struct remote_notif_state.
	<id>: New field.
	(struct remote_notif_state) <pending_event>: New field.
	(notif_event_xfree): Declare.
	* remote-notif.c (handle_notification): Adjust.
	(notif_event_xfree): New function.
	(do_notif_event_xfree): Call notif_event_xfree.
	(remote_notif_state_xfree): Call notif_event_xfree to free
	each element in field pending_event.
	* remote.c (discard_pending_stop_replies): Remove declaration.
	(discard_pending_stop_replies_in_queue): Declare.
	(remote_close): Call discard_pending_stop_replies_in_queue
	instead of discard_pending_stop_replies.
	(remote_start_remote): Adjust.
	(stop_reply_xfree): Call notif_event_xfree.
	(notif_client_stop): Adjust initialization.
	(remote_notif_remove_all): Rename it to ...
	(remove_stop_reply_for_inferior): ... this.  Update comments.
	Don't check INF is NULL.
	(discard_pending_stop_replies): Return early if notif_state is
	NULL.  Adjust.  Don't check INF is NULL.
	(remote_notif_get_pending_events): Adjust.
 	(discard_pending_stop_replies_in_queue): New function.
	(remote_wait_ns): Likewise.

1 files changed, 21 insertions, 8 deletions

diff --git a/gdb/remote-notif.c b/gdb/remote-notif.c
index 905b8a1..0d59279 100644
--- a/gdb/remote-notif.c
+++ b/gdb/remote-notif.c
@@ -51,6 +51,8 @@ static struct notif_client *notifs[] =
   &notif_client_stop,
 };
 
+gdb_static_assert (ARRAY_SIZE (notifs) == REMOTE_NOTIF_LAST);
+
 static void do_notif_event_xfree (void *arg);
 
 /* Parse the BUF for the expected notification NC, and send packet to
@@ -141,7 +143,7 @@ handle_notification (struct remote_notif_state *state, char *buf)
   if (nc == NULL)
     return;
 
-  if (nc->pending_event)
+  if (state->pending_event[nc->id] != NULL)
     {
       /* We've already parsed the in-flight reply, but the stub for some
 	 reason thought we didn't, possibly due to timeout on its side.
@@ -157,7 +159,7 @@ handle_notification (struct remote_notif_state *state, char *buf)
 
       /* Be careful to only set it after parsing, since an error
 	 may be thrown then.  */
-      nc->pending_event = event;
+      state->pending_event[nc->id] = event;
 
       /* Notify the event loop there's a stop reply to acknowledge
 	 and that there may be more events to fetch.  */
@@ -210,19 +212,25 @@ handle_notification (struct remote_notif_state *state, char *buf)
     }
 }
 
-/* Cleanup wrapper.  */
+/* Invoke destructor of EVENT and xfree it.  */
 
-static void
-do_notif_event_xfree (void *arg)
+void
+notif_event_xfree (struct notif_event *event)
 {
-  struct notif_event *event = arg;
-
-  if (event && event->dtr)
+  if (event != NULL && event->dtr != NULL)
     event->dtr (event);
 
   xfree (event);
 }
 
+/* Cleanup wrapper.  */
+
+static void
+do_notif_event_xfree (void *arg)
+{
+  notif_event_xfree (arg);
+}
+
 /* Return an allocated remote_notif_state.  */
 
 struct remote_notif_state *
@@ -246,12 +254,17 @@ remote_notif_state_allocate (void)
 void
 remote_notif_state_xfree (struct remote_notif_state *state)
 {
+  int i;
+
   QUEUE_free (notif_client_p, state->notif_queue);
 
   /* Unregister async_event_handler for notification.  */
   if (state->get_pending_events_token != NULL)
     delete_async_event_handler (&state->get_pending_events_token);
 
+  for (i = 0; i < REMOTE_NOTIF_LAST; i++)
+    notif_event_xfree (state->pending_event[i]);
+
   xfree (state);
 }