aggregator: Release the SRC lock while querying latency

This is required because the query could be intercepted and the
application could send any other requests to the element from this
thread.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/771>

1 files changed, 8 insertions, 2 deletions

diff --git a/libs/gst/base/gstaggregator.c b/libs/gst/base/gstaggregator.c
index f9e71facb5..35e55f0b7a 100644
--- a/libs/gst/base/gstaggregator.c
+++ b/libs/gst/base/gstaggregator.c
@@ -2034,7 +2034,7 @@ gst_aggregator_request_new_pad (GstElement * element,
   return GST_PAD (agg_pad);
 }
 
-/* Must be called with SRC_LOCK held */
+/* Must be called with SRC_LOCK held, temporarily releases it! */
 
 static gboolean
 gst_aggregator_query_latency_unlocked (GstAggregator * self, GstQuery * query)
@@ -2042,7 +2042,10 @@ gst_aggregator_query_latency_unlocked (GstAggregator * self, GstQuery * query)
   gboolean query_ret, live;
   GstClockTime our_latency, min, max;
 
+  /* Temporarily release the lock to do the query. */
+  SRC_UNLOCK (self);
   query_ret = gst_pad_query_default (self->srcpad, GST_OBJECT (self), query);
+  SRC_LOCK (self);
 
   if (!query_ret) {
     GST_WARNING_OBJECT (self, "Latency query failed");
@@ -2068,10 +2071,12 @@ gst_aggregator_query_latency_unlocked (GstAggregator * self, GstQuery * query)
   }
 
   if (min > max && GST_CLOCK_TIME_IS_VALID (max)) {
+    SRC_UNLOCK (self);
     GST_ELEMENT_WARNING (self, CORE, CLOCK, (NULL),
         ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
             GST_TIME_FORMAT ". Add queues or other buffering elements.",
             GST_TIME_ARGS (max), GST_TIME_ARGS (min)));
+    SRC_LOCK (self);
     return FALSE;
   }
 
@@ -2102,7 +2107,8 @@ gst_aggregator_query_latency_unlocked (GstAggregator * self, GstQuery * query)
 }
 
 /*
- * MUST be called with the src_lock held.
+ * MUST be called with the src_lock held. Temporarily releases the lock inside
+ * gst_aggregator_query_latency_unlocked() to do the actual query!
  *
  * See  gst_aggregator_get_latency() for doc
  */