queue2: remove redundant check to avoid posting the same buffering value twice

Remove the percent_changed check to determine whether a buffering message should
be posted. The check on the last posted buffering value is sufficient, and the
removal doesn't introduce additional complexity.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6165>

subprojects/gstreamer/plugins/elements/gstqueue2.c

@@ -264,7 +264,6 @@ static GParamSpec *obj_props[PROP_LAST] = { NULL, };
 #define SET_PERCENT(q, perc) G_STMT_START {                              \
   if (perc != q->buffering_percent) {                                    \
     q->buffering_percent = perc;                                         \
-    q->percent_changed = TRUE;                                           \
     GST_DEBUG_OBJECT (q, "buffering %d percent", perc);                  \
     get_buffering_stats (q, perc, &q->mode, &q->avg_in, &q->avg_out,     \
         &q->buffering_left);                                             \
@@ -1181,28 +1180,27 @@ static GstMessage *
 gst_queue2_get_buffering_message (GstQueue2 * queue, gint * percent)
 {
   GstMessage *msg = NULL;
-  if (queue->percent_changed) {
-    /* Don't change the buffering level if the sinkpad is waiting for
-     * space to become available.  This prevents the situation where,
-     * upstream is pushing buffers larger than our limits so only 1 buffer
-     * is ever in the queue at a time.
-     * Changing the level causes a buffering message to be posted saying that
-     * we are buffering which the application may pause to wait for another
-     * 100% buffering message which would be posted very soon after the
-     * waiting sink thread adds it's buffer to the queue */
-    /* FIXME: This situation above can still occur later if
-     * the sink pad is waiting to push a serialized event into the queue and
-     * the queue becomes empty for a short period of time. */
-    if (!queue->waiting_del
-        && queue->last_posted_buffering_percent != queue->buffering_percent) {
-      *percent = queue->buffering_percent;
 
-      GST_DEBUG_OBJECT (queue, "Going to post buffering: %d%%", *percent);
+  /* Don't change the buffering level if the sinkpad is waiting for
-      msg = gst_message_new_buffering (GST_OBJECT_CAST (queue), *percent);
+   * space to become available.  This prevents the situation where,
+   * upstream is pushing buffers larger than our limits so only 1 buffer
+   * is ever in the queue at a time.
+   * Changing the level causes a buffering message to be posted saying that
+   * we are buffering which the application may pause to wait for another
+   * 100% buffering message which would be posted very soon after the
+   * waiting sink thread adds it's buffer to the queue */
+  /* FIXME: This situation above can still occur later if
+   * the sink pad is waiting to push a serialized event into the queue and
+   * the queue becomes empty for a short period of time. */
+  if (!queue->waiting_del
+      && queue->last_posted_buffering_percent != queue->buffering_percent) {
+    *percent = queue->buffering_percent;
 
-      gst_message_set_buffering_stats (msg, queue->mode, queue->avg_in,
+    GST_DEBUG_OBJECT (queue, "Going to post buffering: %d%%", *percent);
-          queue->avg_out, queue->buffering_left);
+    msg = gst_message_new_buffering (GST_OBJECT_CAST (queue), *percent);
-    }
+
+    gst_message_set_buffering_stats (msg, queue->mode, queue->avg_in,
+        queue->avg_out, queue->buffering_left);
   }
 
   return msg;
@@ -1221,15 +1219,7 @@ gst_queue2_post_buffering (GstQueue2 * queue)
 
   if (msg != NULL) {
     if (gst_element_post_message (GST_ELEMENT_CAST (queue), msg)) {
-      GST_QUEUE2_MUTEX_LOCK (queue);
-      /* Set these states only if posting the message succeeded. Otherwise,
-       * this post attempt failed, and the next one won't be done, because
-       * gst_queue2_get_buffering_message() checks these states and decides
-       * based on their values that it won't produce a message. */
       queue->last_posted_buffering_percent = percent;
-      if (percent == queue->buffering_percent)
-        queue->percent_changed = FALSE;
-      GST_QUEUE2_MUTEX_UNLOCK (queue);
       GST_DEBUG_OBJECT (queue, "successfully posted %d%% buffering message",
           percent);
     } else

subprojects/gstreamer/plugins/elements/gstqueue2.h

@@ -171,7 +171,6 @@ struct _GstQueue2
   gint64 buffering_left;
   gint avg_in;
   gint avg_out;
-  gboolean percent_changed;
   GMutex buffering_post_lock; /* assures only one posted at a time */
 };