pulsesink: prevent race condition causing ref leak

Since commit 8bfd80, gst_pulseringbuffer_stop doesn't wait for the
deferred call to be run before returning. This causes a race when
READY->NULL is executed shortly after, which stops the mainloop. This
leaks the element reference which is passed as userdata for the callback
(introduced in commit 7cf996, bug #614765).

The correct fix is to wait in READY->NULL for all outstanding calls to
be fired (since libpulse doesn't provide a DestroyNotify for the
userdata). We get rid of the reference passing from 7cf996 altogether,
since finalization from the callback would anyways lead to a deadlock.

Re-fixes bug #614765.
This commit is contained in:
René Stadler 2011-06-29 20:59:26 +03:00 committed by Mark Nauwelaerts
parent f8456e2a1a
commit ae87731de5
2 changed files with 17 additions and 3 deletions

View file

@ -988,6 +988,7 @@ gst_pulseringbuffer_clear (GstRingBuffer * buf)
pa_threaded_mainloop_unlock (mainloop);
}
/* called from pulse with the mainloop lock */
static void
mainloop_enter_defer_cb (pa_mainloop_api * api, void *userdata)
{
@ -1005,7 +1006,8 @@ mainloop_enter_defer_cb (pa_mainloop_api * api, void *userdata)
gst_element_post_message (GST_ELEMENT (pulsesink), message);
/* signal the waiter */
g_return_if_fail (pulsesink->defer_pending);
pulsesink->defer_pending--;
pa_threaded_mainloop_signal (mainloop, 0);
}
@ -1022,6 +1024,7 @@ gst_pulseringbuffer_start (GstRingBuffer * buf)
pa_threaded_mainloop_lock (mainloop);
GST_DEBUG_OBJECT (psink, "scheduling stream status");
psink->defer_pending++;
pa_mainloop_api_once (pa_threaded_mainloop_get_api (mainloop),
mainloop_enter_defer_cb, psink);
@ -1065,6 +1068,7 @@ gst_pulseringbuffer_pause (GstRingBuffer * buf)
return res;
}
/* called from pulse with the mainloop lock */
static void
mainloop_leave_defer_cb (pa_mainloop_api * api, void *userdata)
{
@ -1081,8 +1085,9 @@ mainloop_leave_defer_cb (pa_mainloop_api * api, void *userdata)
gst_message_set_stream_status_object (message, &val);
gst_element_post_message (GST_ELEMENT (pulsesink), message);
g_return_if_fail (pulsesink->defer_pending);
pulsesink->defer_pending--;
pa_threaded_mainloop_signal (mainloop, 0);
gst_object_unref (pulsesink);
}
/* stop playback, we flush everything. */
@ -1126,7 +1131,7 @@ cleanup:
}
GST_DEBUG_OBJECT (psink, "scheduling stream status");
gst_object_ref (psink);
psink->defer_pending++;
pa_mainloop_api_once (pa_threaded_mainloop_get_api (mainloop),
mainloop_leave_defer_cb, psink);
@ -2566,6 +2571,13 @@ gst_pulsesink_release_mainloop (GstPulseSink * psink)
if (!mainloop)
return;
pa_threaded_mainloop_lock (mainloop);
while (psink->defer_pending) {
GST_DEBUG_OBJECT (psink, "waiting for stream status message emission");
pa_threaded_mainloop_wait (mainloop);
}
pa_threaded_mainloop_unlock (mainloop);
g_mutex_lock (pa_shared_resource_mutex);
mainloop_ref_ct--;
if (!mainloop_ref_ct) {

View file

@ -64,6 +64,8 @@ struct _GstPulseSink
gboolean mute:1;
gboolean mute_set:1;
guint defer_pending;
gint notify; /* atomic */
const gchar *pa_version;