[FFmpeg-devel] [PATCH 1/3] lavc/pthread_frame: protect read state access in setup finish function

Ronald S. Bultje rsbultje at gmail.com
Fri Jan 13 16:07:48 EET 2017


Hi,

On Jan 13, 2017 6:40 AM, "Clément Bœsch" <u at pkh.me> wrote:

From: Clément Bœsch <cboesch at gopro.com>

---
 libavcodec/pthread_frame.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c
index 7ef5e9f6be..cb6d76284e 100644
--- a/libavcodec/pthread_frame.c
+++ b/libavcodec/pthread_frame.c
@@ -509,11 +509,11 @@ void ff_thread_finish_setup(AVCodecContext *avctx) {

     if (!(avctx->active_thread_type&FF_THREAD_FRAME)) return;

+    pthread_mutex_lock(&p->progress_mutex);
     if(p->state == STATE_SETUP_FINISHED){
         av_log(avctx, AV_LOG_WARNING, "Multiple ff_thread_finish_setup()
calls\n");
     }

-    pthread_mutex_lock(&p->progress_mutex);


This has a problem in that we're potentially calling an I/O function that
potentially directly enters application space with a lock held.

Can the av_log call be moved under a local variable for the condition to
after the lock is released?

Ronald


More information about the ffmpeg-devel mailing list