rtpssrcdemux: Avoid taking streamlock out-of-band

[platform/upstream/gst-plugins-good.git] / gst / rtpmanager / gstrtpssrcdemux.c

diff --git a/gst/rtpmanager/gstrtpssrcdemux.c b/gst/rtpmanager/gstrtpssrcdemux.c
index 1661e79..880e8f2 100644 (file)
--- a/gst/rtpmanager/gstrtpssrcdemux.c
+++ b/gst/rtpmanager/gstrtpssrcdemux.c
@@ -145,6 +145,7 @@ struct _GstRtpSsrcDemuxPad
 };
 
 /* find a src pad for a given SSRC, returns NULL if the SSRC was not found
+ * MUST be called with object lock
  */
 static GstRtpSsrcDemuxPad *
 find_demux_pad_for_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc)
@@ -160,6 +161,38 @@ find_demux_pad_for_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc)
   return NULL;
 }
 
+/* returns a reference to the pad if found, %NULL otherwise */
+static GstPad *
+get_demux_pad_for_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc, PadType padtype)
+{
+  GstRtpSsrcDemuxPad *demuxpad;
+  GstPad *retpad;
+
+  GST_OBJECT_LOCK (demux);
+
+  demuxpad = find_demux_pad_for_ssrc (demux, ssrc);
+  if (!demuxpad) {
+    GST_OBJECT_UNLOCK (demux);
+    return NULL;
+  }
+
+  switch (padtype) {
+    case RTP_PAD:
+      retpad = gst_object_ref (demuxpad->rtp_pad);
+      break;
+    case RTCP_PAD:
+      retpad = gst_object_ref (demuxpad->rtcp_pad);
+      break;
+    default:
+      retpad = NULL;
+      g_assert_not_reached ();
+  }
+
+  GST_OBJECT_UNLOCK (demux);
+
+  return retpad;
+}
+
 static GstEvent *
 add_ssrc_and_ref (GstEvent * event, guint32 ssrc)
 {
@@ -229,6 +262,7 @@ forward_initial_events (GstRtpSsrcDemux * demux, guint32 ssrc, GstPad * pad,
   gst_pad_sticky_events_foreach (sinkpad, forward_sticky_events, &fdata);
 }
 
+/* MUST only be called from streaming thread */
 static GstPad *
 find_or_create_demux_pad_for_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc,
     PadType padtype)
@@ -242,22 +276,9 @@ find_or_create_demux_pad_for_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc,
 
   INTERNAL_STREAM_LOCK (demux);
 
-  demuxpad = find_demux_pad_for_ssrc (demux, ssrc);
-  if (demuxpad != NULL) {
-    switch (padtype) {
-      case RTP_PAD:
-        retpad = gst_object_ref (demuxpad->rtp_pad);
-        break;
-      case RTCP_PAD:
-        retpad = gst_object_ref (demuxpad->rtcp_pad);
-        break;
-      default:
-        retpad = NULL;
-        g_assert_not_reached ();
-    }
-
+  retpad = get_demux_pad_for_ssrc (demux, ssrc, padtype);
+  if (retpad != NULL) {
     INTERNAL_STREAM_UNLOCK (demux);
-
     return retpad;
   }
 
@@ -283,7 +304,9 @@ find_or_create_demux_pad_for_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc,
   gst_pad_set_element_private (rtp_pad, demuxpad);
   gst_pad_set_element_private (rtcp_pad, demuxpad);
 
+  GST_OBJECT_LOCK (demux);
   demux->srcpads = g_slist_prepend (demux->srcpads, demuxpad);
+  GST_OBJECT_UNLOCK (demux);
 
   gst_pad_set_query_function (rtp_pad, gst_rtp_ssrc_demux_src_query);
   gst_pad_set_iterate_internal_links_function (rtp_pad,
@@ -316,17 +339,11 @@ find_or_create_demux_pad_for_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc,
       g_assert_not_reached ();
   }
 
-  gst_object_ref (rtp_pad);
-  gst_object_ref (rtcp_pad);
-
   g_signal_emit (G_OBJECT (demux),
       gst_rtp_ssrc_demux_signals[SIGNAL_NEW_SSRC_PAD], 0, ssrc, rtp_pad);
 
   INTERNAL_STREAM_UNLOCK (demux);
 
-  gst_object_unref (rtp_pad);
-  gst_object_unref (rtcp_pad);
-
   return retpad;
 }
 
@@ -486,17 +503,17 @@ gst_rtp_ssrc_demux_clear_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc)
 {
   GstRtpSsrcDemuxPad *dpad;
 
-  INTERNAL_STREAM_LOCK (demux);
+  GST_OBJECT_LOCK (demux);
   dpad = find_demux_pad_for_ssrc (demux, ssrc);
   if (dpad == NULL) {
-    INTERNAL_STREAM_UNLOCK (demux);
+    GST_OBJECT_UNLOCK (demux);
     goto unknown_pad;
   }
 
   GST_DEBUG_OBJECT (demux, "clearing pad for SSRC %08x", ssrc);
 
   demux->srcpads = g_slist_remove (demux->srcpads, dpad);
-  INTERNAL_STREAM_UNLOCK (demux);
+  GST_OBJECT_UNLOCK (demux);
 
   gst_pad_set_active (dpad->rtp_pad, FALSE);
   gst_pad_set_active (dpad->rtcp_pad, FALSE);
@@ -535,7 +552,7 @@ forward_event (GstPad * pad, gpointer user_data)
   GSList *walk = NULL;
   GstEvent *newevent = NULL;
 
-  INTERNAL_STREAM_LOCK (fdata->demux);
+  GST_OBJECT_LOCK (fdata->demux);
   for (walk = fdata->demux->srcpads; walk; walk = walk->next) {
     GstRtpSsrcDemuxPad *dpad = (GstRtpSsrcDemuxPad *) walk->data;
 
@@ -544,7 +561,7 @@ forward_event (GstPad * pad, gpointer user_data)
       break;
     }
   }
-  INTERNAL_STREAM_UNLOCK (fdata->demux);
+  GST_OBJECT_UNLOCK (fdata->demux);
 
   if (newevent)
     fdata->res &= gst_pad_push_event (pad, newevent);
@@ -582,7 +599,6 @@ gst_rtp_ssrc_demux_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
   guint32 ssrc;
   GstRTPBuffer rtp = { NULL };
   GstPad *srcpad;
-  GstRtpSsrcDemuxPad *dpad;
 
   demux = GST_RTP_SSRC_DEMUX (parent);
 
@@ -602,14 +618,17 @@ gst_rtp_ssrc_demux_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
   ret = gst_pad_push (srcpad, buf);
 
   if (ret != GST_FLOW_OK) {
+    GstPad *active_pad;
+
     /* check if the ssrc still there, may have been removed */
-    INTERNAL_STREAM_LOCK (demux);
-    dpad = find_demux_pad_for_ssrc (demux, ssrc);
-    if (dpad == NULL || dpad->rtp_pad != srcpad) {
+    active_pad = get_demux_pad_for_ssrc (demux, ssrc, RTP_PAD);
+
+    if (active_pad == NULL || active_pad != srcpad) {
       /* SSRC was removed during the push ... ignore the error */
       ret = GST_FLOW_OK;
     }
-    INTERNAL_STREAM_UNLOCK (demux);
+
+    g_clear_object (&active_pad);
   }
 
   gst_object_unref (srcpad);
@@ -644,7 +663,6 @@ gst_rtp_ssrc_demux_rtcp_chain (GstPad * pad, GstObject * parent,
   GstRTCPPacket packet;
   GstRTCPBuffer rtcp = { NULL, };
   GstPad *srcpad;
-  GstRtpSsrcDemuxPad *dpad;
 
   demux = GST_RTP_SSRC_DEMUX (parent);
 
@@ -689,14 +707,16 @@ gst_rtp_ssrc_demux_rtcp_chain (GstPad * pad, GstObject * parent,
   ret = gst_pad_push (srcpad, buf);
 
   if (ret != GST_FLOW_OK) {
+    GstPad *active_pad;
+
     /* check if the ssrc still there, may have been removed */
-    INTERNAL_STREAM_LOCK (demux);
-    dpad = find_demux_pad_for_ssrc (demux, ssrc);
-    if (dpad == NULL || dpad->rtcp_pad != srcpad) {
+    active_pad = get_demux_pad_for_ssrc (demux, ssrc, RTCP_PAD);
+    if (active_pad == NULL || active_pad != srcpad) {
       /* SSRC was removed during the push ... ignore the error */
       ret = GST_FLOW_OK;
     }
-    INTERNAL_STREAM_UNLOCK (demux);
+
+    g_clear_object (&active_pad);
   }
 
   gst_object_unref (srcpad);
@@ -786,7 +806,7 @@ gst_rtp_ssrc_demux_iterate_internal_links_src (GstPad * pad, GstObject * parent)
 
   demux = GST_RTP_SSRC_DEMUX (parent);
 
-  INTERNAL_STREAM_LOCK (demux);
+  GST_OBJECT_LOCK (demux);
   for (current = demux->srcpads; current; current = g_slist_next (current)) {
     GstRtpSsrcDemuxPad *dpad = (GstRtpSsrcDemuxPad *) current->data;
 
@@ -807,7 +827,7 @@ gst_rtp_ssrc_demux_iterate_internal_links_src (GstPad * pad, GstObject * parent)
     g_value_unset (&val);
 
   }
-  INTERNAL_STREAM_UNLOCK (demux);
+  GST_OBJECT_UNLOCK (demux);
 
   return it;
 }