Original commit message from CVS:
* ext/jack/gstjackaudiosink.c: (gst_jack_audio_sink_class_init):
Work around missing bits of thread-safety on older GLibs some
more to avoid assertions when starting up multiple playbin
objects concurrently (see #512382).
gstbaseaudiosink_class->create_ringbuffer =
GST_DEBUG_FUNCPTR (gst_jack_audio_sink_create_ringbuffer);
+ /* ref class from a thread-safe context to work around missing bit of
+ * thread-safety in GObject */
+ g_type_class_ref (GST_TYPE_JACK_RING_BUFFER);
+
gst_jack_audio_client_init ();
}