[FFmpeg-cvslog] avformat: make av_register_*put_format() thread safe

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sat Jun 29 03:44:15 2013 +0200| [53fd1ab26bec7d045d168590bf49de722e2a601c] | committer: Michael Niedermayer

avformat: make av_register_*put_format() thread safe

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=53fd1ab26bec7d045d168590bf49de722e2a601c
---

 libavformat/format.c |   13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/libavformat/format.c b/libavformat/format.c
index c1be859..ac9100b 100644
--- a/libavformat/format.c
+++ b/libavformat/format.c
@@ -21,6 +21,7 @@
 
 #include "avformat.h"
 #include "internal.h"
+#include "libavutil/atomic.h"
 #include "libavutil/avstring.h"
 
 /**
@@ -52,22 +53,18 @@ void av_register_input_format(AVInputFormat *format)
 {
     AVInputFormat **p = &first_iformat;
 
-    while (*p != NULL)
-        p = &(*p)->next;
-
-    *p = format;
     format->next = NULL;
+    while(avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
+        p = &(*p)->next;
 }
 
 void av_register_output_format(AVOutputFormat *format)
 {
     AVOutputFormat **p = &first_oformat;
 
-    while (*p != NULL)
-        p = &(*p)->next;
-
-    *p = format;
     format->next = NULL;
+    while(avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
+        p = &(*p)->next;
 }
 
 int av_match_ext(const char *filename, const char *extensions)