Currently in ff_thread_decode_frame, context is updated from child thread
to user thread, and user thread releases the context in avcodec_close()
when decode finishes.
However, when resolution/format changes, ff_get_format is called, and
hwaccel_uninit() and hwaccel_init will be used to destroy and re-create
the context. Due to the async between user-thread and child-thread,
user-thread updates its context from child earlier than the context
is refreshed in child-thread. And it will lead to:
1. memory leak in child-thread.
2. double free in user-thread while calling avcodec_close().
Can be reproduced with a resolution change case, and use -vframes
to terminate the decode between the dynamic resolution changing frames:
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -v
verbose -i ./test2360_1672_4980.ivf -pix_fmt p010le -f rawvideo -vsync
passthrough -vframes 6 -y out.yuv
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -v verbose -i
./reinit-large_420_8-to-small_420_8.h264 -pix_fmt nv12 -f rawvideo
-vsync passthrough -vframes 45 -y out.yuv
Move update_context_from_thread from ff_thread_decode_frame(user thread)
to frame_worker_thread(child thread), update the context in child thread
right after the context is refreshed to avoid the async issue.
Signed-off-by: Linjie Fu <linjie...@intel.com>
---
libavcodec/internal.h | 7 +++++++
libavcodec/pthread_frame.c | 21 ++++++++++++++++++---
2 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/libavcodec/internal.h b/libavcodec/internal.h
index 5096ffa..a85ffff 100644
--- a/libavcodec/internal.h
+++ b/libavcodec/internal.h
@@ -162,6 +162,13 @@ typedef struct AVCodecInternal {
void *thread_ctx;
+ /**
+ * User thread AVCodecContext pointer and
+ * context mutex
+ */
+ void *user_avctx;
+ pthread_mutex_t context_mutex;
+
DecodeSimpleContext ds;
DecodeFilterContext filter;
diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c
index 36ac0ac..60110f2 100644
--- a/libavcodec/pthread_frame.c
+++ b/libavcodec/pthread_frame.c
@@ -140,6 +140,8 @@ typedef struct FrameThreadContext {
#define THREAD_SAFE_CALLBACKS(avctx) \
((avctx)->thread_safe_callbacks || (avctx)->get_buffer2 ==
avcodec_default_get_buffer2)
+static int update_context_from_thread(AVCodecContext *dst, AVCodecContext
*src, int for_user);
+
static void async_lock(FrameThreadContext *fctx)
{
pthread_mutex_lock(&fctx->async_mutex);
@@ -157,7 +159,6 @@ static void async_unlock(FrameThreadContext *fctx)
pthread_cond_broadcast(&fctx->async_cond);
pthread_mutex_unlock(&fctx->async_mutex);
}
-
/**
* Codec worker thread.
*
@@ -169,6 +170,7 @@ static attribute_align_arg void *frame_worker_thread(void
*arg)
{
PerThreadContext *p = arg;
AVCodecContext *avctx = p->avctx;
+ AVCodecContext *user_avctx = p->avctx->internal->user_avctx;
const AVCodec *codec = avctx->codec;
pthread_mutex_lock(&p->mutex);
@@ -200,6 +202,12 @@ static attribute_align_arg void *frame_worker_thread(void
*arg)
p->got_frame = 0;
p->result = codec->decode(avctx, p->frame, &p->got_frame, &p->avpkt);
+ if (user_avctx) {
+ pthread_mutex_lock(&user_avctx->internal->context_mutex);
+ update_context_from_thread(user_avctx, p->avctx, 1);
+ pthread_mutex_unlock(&user_avctx->internal->context_mutex);
+ }
+
if ((p->result < 0 || !p->got_frame) && p->frame->buf[0]) {
if (avctx->internal->allocate_progress)
av_log(avctx, AV_LOG_ERROR, "A frame threaded decoder did not "
@@ -390,7 +398,9 @@ static int submit_packet(PerThreadContext *p,
AVCodecContext *user_avctx,
pthread_mutex_lock(&p->mutex);
+ pthread_mutex_lock(&user_avctx->internal->context_mutex);
ret = update_context_from_user(p->avctx, user_avctx);
+ pthread_mutex_unlock(&user_avctx->internal->context_mutex);
if (ret) {
pthread_mutex_unlock(&p->mutex);
return ret;
@@ -540,8 +550,6 @@ int ff_thread_decode_frame(AVCodecContext *avctx,
if (finished >= avctx->thread_count) finished = 0;
} while (!avpkt->size && !*got_picture_ptr && err >= 0 && finished !=
fctx->next_finished);
- update_context_from_thread(avctx, p->avctx, 1);
-
if (fctx->next_decoding >= avctx->thread_count) fctx->next_decoding = 0;
fctx->next_finished = finished;
@@ -713,6 +721,8 @@ void ff_frame_thread_free(AVCodecContext *avctx, int
thread_count)
pthread_mutex_destroy(&fctx->async_mutex);
pthread_cond_destroy(&fctx->async_cond);
+ pthread_mutex_destroy(&avctx->internal->context_mutex);
+
av_freep(&avctx->internal->thread_ctx);
if (avctx->priv_data && avctx->codec && avctx->codec->priv_class)
@@ -728,6 +738,8 @@ int ff_frame_thread_init(AVCodecContext *avctx)
FrameThreadContext *fctx;
int i, err = 0;
+ avctx->internal->user_avctx = avctx;
+
if (!thread_count) {
int nb_cpus = av_cpu_count();
#if FF_API_DEBUG_MV
@@ -761,6 +773,8 @@ int ff_frame_thread_init(AVCodecContext *avctx)
pthread_mutex_init(&fctx->async_mutex, NULL);
pthread_cond_init(&fctx->async_cond, NULL);
+ pthread_mutex_init(&avctx->internal->context_mutex, NULL);
+
fctx->async_lock = 1;
fctx->delaying = 1;
@@ -800,6 +814,7 @@ int ff_frame_thread_init(AVCodecContext *avctx)
*copy->internal = *src->internal;
copy->internal->thread_ctx = p;
copy->internal->last_pkt_props = &p->avpkt;
+ copy->internal->user_avctx = avctx;
if (!i) {
src = copy;
--
2.7.4
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