[FFmpeg-devel] [PATCH 1/4] avcodec/allcodecs: make avcodec_register_all thread safe

[Muhammad Faiz]

Signed-off-by: Muhammad Faiz <mfcc64 at gmail.com>
---
 libavcodec/allcodecs.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index eee322b..1d05fc1 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -24,6 +24,8 @@
  * Provide registration of all codecs, parsers and bitstream filters for libavcodec.
  */
 
+#include <stdatomic.h>
+
 #include "config.h"
 #include "avcodec.h"
 #include "version.h"
@@ -60,11 +62,14 @@
 
 void avcodec_register_all(void)
 {
-    static int initialized;
+    static atomic_int initialized;
+    static atomic_int ready;
 
-    if (initialized)
+    if (atomic_exchange_explicit(&initialized, 1, memory_order_relaxed)) {
+        while (!atomic_load_explicit(&ready, memory_order_relaxed))
+            ;
         return;
-    initialized = 1;
+    }
 
     /* hardware accelerators */
     REGISTER_HWACCEL(H263_VAAPI,        h263_vaapi);
@@ -716,4 +721,6 @@ void avcodec_register_all(void)
     REGISTER_PARSER(VP8,                vp8);
     REGISTER_PARSER(VP9,                vp9);
     REGISTER_PARSER(XMA,                xma);
+
+    atomic_store_explicit(&ready, 1, memory_order_relaxed);
 }
-- 
2.9.3