[FFmpeg-cvslog] lagarith: assign correct per-thread value to LagarithContext::avctx.

[Ronald S. Bultje]

ffmpeg | branch: master | Ronald S. Bultje <rsbultje at gmail.com> | Tue Mar 28 20:11:43 2017 -0400| [081c21ca55d72921125848c8c2c191a6ff8b5f88] | committer: Ronald S. Bultje

lagarith: assign correct per-thread value to LagarithContext::avctx.

This fixes race conditions reported by tsan in fate-lagarith. The races
were because each thread's LagarithContext::avctx was set to the first
thread's AVCodecContext.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=081c21ca55d72921125848c8c2c191a6ff8b5f88
---

 libavcodec/lagarith.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/libavcodec/lagarith.c b/libavcodec/lagarith.c
index f03305f..469eec4 100644
--- a/libavcodec/lagarith.c
+++ b/libavcodec/lagarith.c
@@ -730,6 +730,16 @@ static av_cold int lag_decode_init(AVCodecContext *avctx)
     return 0;
 }
 
+#if HAVE_THREADS
+static av_cold int lag_decode_init_thread_copy(AVCodecContext *avctx)
+{
+    LagarithContext *l = avctx->priv_data;
+    l->avctx = avctx;
+
+    return 0;
+}
+#endif
+
 static av_cold int lag_decode_end(AVCodecContext *avctx)
 {
     LagarithContext *l = avctx->priv_data;
@@ -746,6 +756,7 @@ AVCodec ff_lagarith_decoder = {
     .id             = AV_CODEC_ID_LAGARITH,
     .priv_data_size = sizeof(LagarithContext),
     .init           = lag_decode_init,
+    .init_thread_copy = ONLY_IF_THREADS_ENABLED(lag_decode_init_thread_copy),
     .close          = lag_decode_end,
     .decode         = lag_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,