[vlc-commits] pulse: fix race in TimeGet()

[Rémi Denis-Courmont]

vlc/vlc-2.2 | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Sat Aug 22 12:16:45 2015 +0300| [f849a36c161e59b28063f522d3c7b8a3e602233a] | committer: Rémi Denis-Courmont

pulse: fix race in TimeGet()

Cork state could change asynchronously without the PA lock.

(cherry picked from commit 88655e00d0d90459b37ad1684dd7686c743ee4a7)

> http://git.videolan.org/gitweb.cgi/vlc/vlc-2.2.git/?a=commit;h=f849a36c161e59b28063f522d3c7b8a3e602233a
---

 modules/audio_output/pulse.c |   22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/modules/audio_output/pulse.c b/modules/audio_output/pulse.c
index 231769d..514f47c 100644
--- a/modules/audio_output/pulse.c
+++ b/modules/audio_output/pulse.c
@@ -441,16 +441,20 @@ static int TimeGet(audio_output_t *aout, mtime_t *restrict delay)
 {
     aout_sys_t *sys = aout->sys;
     pa_stream *s = sys->stream;
+    int ret = -1;
 
-    if (pa_stream_is_corked(s) > 0)
-        return -1; /* latency is irrelevant if corked */
-
-    mtime_t delta = vlc_pa_get_latency(aout, sys->context, s);
-    if (delta == VLC_TS_INVALID)
-        return -1;
-
-    *delay = delta;
-    return 0;
+    pa_threaded_mainloop_lock(sys->mainloop);
+    if (pa_stream_is_corked(s) <= 0)
+    {   /* latency is relevant only if not corked */
+        mtime_t delta = vlc_pa_get_latency(aout, sys->context, s);
+        if (delta != VLC_TS_INVALID)
+        {
+            *delay = delta;
+            ret = 0;
+        }
+    }
+    pa_threaded_mainloop_unlock(sys->mainloop);
+    return ret;
 }
 
 /* Memory free callback. The block_t address is in front of the data. */