[FFmpeg-devel] [PATCH] ffplay: more robust thread creation

[Marton Balint]

On Sat, 3 Oct 2015, Ganesh Ajjanagadde wrote:

> SDL_CreateThread can fail:
> https://wiki.libsdl.org/SDL_CreateThread.
> This patch makes thread creation more robust in one instance.
>
> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> ---
> ffplay.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/ffplay.c b/ffplay.c
> index b7b2b0b..da0fd3a 100644
> --- a/ffplay.c
> +++ b/ffplay.c
> @@ -2080,10 +2080,15 @@ static int audio_thread(void *arg)
>     return ret;
> }
> 
> -static void decoder_start(Decoder *d, int (*fn)(void *), void *arg)
> +static int decoder_start(Decoder *d, int (*fn)(void *), void *arg)
> {
>     packet_queue_start(d->queue);
>     d->decoder_tid = SDL_CreateThread(fn, arg);
> +    if (!d->decoder_tid) {
> +        av_log(d, AV_LOG_FATAL, "SDL_CreateThread(): %s\n", SDL_GetError());
> +        return AVERROR(ENOMEM);
> +    }
> +    return 0;
> }
> 
> static int video_thread(void *arg)
> @@ -2681,7 +2686,8 @@ static int stream_component_open(VideoState *is, int stream_index)
>             is->auddec.start_pts = is->audio_st->start_time;
>             is->auddec.start_pts_tb = is->audio_st->time_base;
>         }
> -        decoder_start(&is->auddec, audio_thread, is);
> +        if (decoder_start(&is->auddec, audio_thread, is) < 0)
> +            goto fail;
>         SDL_PauseAudio(0);
>         break;
>     case AVMEDIA_TYPE_VIDEO:
> @@ -2692,7 +2698,8 @@ static int stream_component_open(VideoState *is, int stream_index)
>         is->viddec_height = avctx->height;
>
>         decoder_init(&is->viddec, avctx, &is->videoq, is->continue_read_thread);
> -        decoder_start(&is->viddec, video_thread, is);
> +        if (decoder_start(&is->viddec, video_thread, is) < 0)
> +            goto fail;
>         is->queue_attachments_req = 1;
>         break;
>     case AVMEDIA_TYPE_SUBTITLE:
> @@ -2700,7 +2707,8 @@ static int stream_component_open(VideoState *is, int stream_index)
>         is->subtitle_st = ic->streams[stream_index];
>
>         decoder_init(&is->subdec, avctx, &is->subtitleq, is->continue_read_thread);
> -        decoder_start(&is->subdec, subtitle_thread, is);
> +        if (decoder_start(&is->subdec, subtitle_thread, is) < 0)
> +            goto fail;

You should propagate the error code to the failure path, otherwise 
stream_component_open will simply return with zero in case of error as 
well.

Regards,
Marton