score: Move message notification

Move message notification to end of critical section and delegate the
message queue release to the notification handler.  It may do more
complex notification actions out of the critical section.

Update #2555.

1 files changed, 21 insertions, 0 deletions

diff --git a/cpukit/score/src/coremsgsubmit.c b/cpukit/score/src/coremsgsubmit.c
index 1d6d298ea7..7e589e7754 100644
--- a/cpukit/score/src/coremsgsubmit.c
+++ b/cpukit/score/src/coremsgsubmit.c
@@ -79,7 +79,28 @@ CORE_message_queue_Status _CORE_message_queue_Do_submit(
       size,
       submit_type
     );
+
+#if defined(RTEMS_SCORE_COREMSG_ENABLE_NOTIFICATION)
+    /*
+     *  According to POSIX, does this happen before or after the message
+     *  is actually enqueued.  It is logical to think afterwards, because
+     *  the message is actually in the queue at this point.
+     */
+    if (
+      the_message_queue->number_of_pending_messages == 1
+        && the_message_queue->notify_handler != NULL
+    ) {
+      ( *the_message_queue->notify_handler )(
+        the_message_queue,
+        lock_context
+      );
+    } else {
+      _CORE_message_queue_Release( the_message_queue, lock_context );
+    }
+#else
     _CORE_message_queue_Release( the_message_queue, lock_context );
+#endif
+
     return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
   }