tests: rtprtx::test_rtxreceive_data_reconstruction: fix race condition

Now with rtprtxsend pushing rtx buffers from a different thread,
this is necessary to ensure that the result of the test is deterministic.

This code makes use of GstCheck's global GMutex and GCond that are
being used inside GstCheck's sink pad chain() function in order
to synchronize with it.

1 files changed, 22 insertions, 3 deletions

diff --git a/tests/check/elements/rtprtx.c b/tests/check/elements/rtprtx.c
index a1ddcbfe5..759786e70 100644
--- a/tests/check/elements/rtprtx.c
+++ b/tests/check/elements/rtprtx.c
@@ -1447,12 +1447,31 @@ GST_START_TEST (test_rtxreceive_data_reconstruction)
   gst_check_setup_events (srcpad, rtxsend, caps, GST_FORMAT_TIME);
   gst_caps_unref (caps);
 
-  /* push buffer and retransmission request */
+  /* push buffer */
   buffer = gst_buffer_ref (GST_BUFFER (in_buffers->data));
   fail_unless_equals_int (gst_pad_push (srcpad, gst_buffer_ref (buffer)),
       GST_FLOW_OK);
-  fail_unless_equals_int (gst_pad_push_event (sinkpad,
-          create_rtx_event (1, ssrc, payload_type)), TRUE);
+
+  /* push retransmission request */
+  {
+    GList *last_out_buffer;
+    guint64 end_time;
+    gboolean res;
+
+    /* synchronize with the chain() function of the "sinkpad"
+     * to make sure that rtxsend has pushed the rtx buffer out
+     * before continuing */
+    last_out_buffer = g_list_last (buffers);
+    g_mutex_lock (&check_mutex);
+    fail_unless_equals_int (gst_pad_push_event (sinkpad,
+            create_rtx_event (1, ssrc, payload_type)), TRUE);
+    end_time = g_get_monotonic_time () + G_TIME_SPAN_SECOND;
+    do
+      res = g_cond_wait_until (&check_cond, &check_mutex, end_time);
+    while (res == TRUE && last_out_buffer == g_list_last (buffers));
+    fail_unless_equals_int (res, TRUE);
+    g_mutex_unlock (&check_mutex);
+  }
 
   /* push with the next seqnum to trigger retransmission in rtxsend */
   buffer = gst_buffer_make_writable (buffer);