[FFmpeg-devel] [PATCH 7/7] lavc: do not hold the codec init lock longer than necessary

Anton Khirnov anton at khirnov.net
Wed Mar 10 14:03:32 EET 2021


The only potentially unsafe operation is the codec-specific init
function.
---
 libavcodec/utils.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index e0f6234bd7..952adb5277 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -570,8 +570,6 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
     if (options)
         av_dict_copy(&tmp, *options, 0);
 
-    lock_avcodec(codec);
-
     avci = av_mallocz(sizeof(*avci));
     if (!avci) {
         ret = AVERROR(ENOMEM);
@@ -723,9 +721,7 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
         av_log(avctx, AV_LOG_WARNING, "Warning: not compiled with thread support, using thread emulation\n");
 
     if (CONFIG_FRAME_THREAD_ENCODER && av_codec_is_encoder(avctx->codec)) {
-        unlock_avcodec(codec); //we will instantiate a few encoders thus kick the counter to prevent false detection of a problem
         ret = ff_frame_thread_encoder_init(avctx, options ? *options : NULL);
-        lock_avcodec(codec);
         if (ret < 0)
             goto free_and_end;
     }
@@ -749,7 +745,9 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
 
     if (   avctx->codec->init && (!(avctx->active_thread_type&FF_THREAD_FRAME)
         || avci->frame_thread_encoder)) {
+        lock_avcodec(codec);
         ret = avctx->codec->init(avctx);
+        unlock_avcodec(codec);
         if (ret < 0) {
             codec_init_ok = -1;
             goto free_and_end;
@@ -834,7 +832,6 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
     }
 
 end:
-    unlock_avcodec(codec);
     if (options) {
         av_dict_free(options);
         *options = tmp;
-- 
2.30.1



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