[gst-cvs] gstreamer: multiqueue: avoid lock for taking the counter

[Wim Taymans]

Module: gstreamer
Branch: master
Commit: b95cc5031b86549e955aa1fd981a3e8a68e73e60
URL:    http://cgit.freedesktop.org/gstreamer/gstreamer/commit/?id=b95cc5031b86549e955aa1fd981a3e8a68e73e60

Author: Wim Taymans <wim.taymans at collabora.co.uk>
Date:   Wed Oct 21 13:38:57 2009 -0400

multiqueue: avoid lock for taking the counter

The counter for incomming data is already protected with the STREAM_LOCK so we
don't need to add another lock around it.

---

 plugins/elements/gstmultiqueue.c |    7 ++-----
 plugins/elements/gstmultiqueue.h |    2 +-
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/plugins/elements/gstmultiqueue.c b/plugins/elements/gstmultiqueue.c
index 938825a..30b7bc6 100644
--- a/plugins/elements/gstmultiqueue.c
+++ b/plugins/elements/gstmultiqueue.c
@@ -1014,9 +1014,7 @@ gst_multi_queue_chain (GstPad * pad, GstBuffer * buffer)
   mq = sq->mqueue;
 
   /* Get a unique incrementing id */
-  GST_MULTI_QUEUE_MUTEX_LOCK (mq);
   curid = mq->counter++;
-  GST_MULTI_QUEUE_MUTEX_UNLOCK (mq);
 
   GST_LOG_OBJECT (mq, "SingleQueue %d : about to enqueue buffer %p with id %d",
       sq->id, buffer, curid);
@@ -1112,10 +1110,9 @@ gst_multi_queue_sink_event (GstPad * pad, GstEvent * event)
       break;
   }
 
-  /* Get an unique incrementing id */
-  GST_MULTI_QUEUE_MUTEX_LOCK (mq);
+  /* Get an unique incrementing id. protected with the STREAM_LOCK, unserialized
+   * events already got pushed and don't end up in the queue. */
   curid = mq->counter++;
-  GST_MULTI_QUEUE_MUTEX_UNLOCK (mq);
 
   item = gst_multi_queue_event_item_new ((GstMiniObject *) event, curid);
 
diff --git a/plugins/elements/gstmultiqueue.h b/plugins/elements/gstmultiqueue.h
index 7a96d77..088b431 100644
--- a/plugins/elements/gstmultiqueue.h
+++ b/plugins/elements/gstmultiqueue.h
@@ -59,7 +59,7 @@ struct _GstMultiQueue {
 
   GstDataQueueSize  max_size, extra_size;
 
-  guint32  counter;	/* incoming object counter */
+  guint32  counter;	/* incoming object counter, protected with STREAM_LOCK */
   guint32  highid;	/* contains highest id of last outputted object */
 
   GMutex * qlock;	/* Global queue lock (vs object lock or individual */