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

[Andreas Rheinhardt]

Anton Khirnov:
> 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;
> 
ff_frame_thread_init also calls codec->init directly.

- Andreas