[FFmpeg-devel] [PATCH 3/4] avfilter/allfilters: make avfilter_register_all thread safe

[Muhammad Faiz]

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

diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 15a74c4..2042b35 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -19,6 +19,8 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <stdatomic.h>
+
 #include "avfilter.h"
 #include "config.h"
 #include "opencl_allkernels.h"
@@ -39,11 +41,14 @@
 
 void avfilter_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;
+    }
 
     REGISTER_FILTER(ABENCH,         abench,         af);
     REGISTER_FILTER(ACOMPRESSOR,    acompressor,    af);
@@ -379,4 +384,6 @@ void avfilter_register_all(void)
     REGISTER_FILTER_UNCONDITIONAL(af_afifo);
     REGISTER_FILTER_UNCONDITIONAL(vf_fifo);
     ff_opencl_register_filter_kernel_code_all();
+
+    atomic_store_explicit(&ready, 1, memory_order_relaxed);
 }
-- 
2.9.3