> -----Original Message----- > From: ffmpeg-devel [mailto:ffmpeg-devel-boun...@ffmpeg.org] On Behalf > Of Hendrik Leppkes > Sent: Wednesday, June 26, 2019 15:12 > To: FFmpeg development discussions and patches <ffmpeg- > de...@ffmpeg.org> > Subject: Re: [FFmpeg-devel] [PATCH, RFC] lavc/phtread_frame: update > context in child thread in multi-thread mode > > On Wed, Jun 26, 2019 at 9:06 AM Linjie Fu <linjie...@intel.com> wrote: > > > > Currently in ff_thread_decode_frame, context is updated from child > thread > > to main thread, and main thread releases the context in avcodec_close() > > when decode finishes. > > > > However, when resolution/format change in vp9, ff_get_format was called, > > and hwaccel_uninit() and hwaccel_init will be used to destroy and re- > create > > the context. Due to the async between main-thread and child-thread, > > main-thread updated its context from child earlier than the context was > > refreshed in child-thread. And it will lead to: > > 1. memory leak in child-thread. > > 2. double free in main-thread while calling avcodec_close(). > > > > Can be reproduced with a resolution change case in vp9, and use -vframes > > to terminate the decode between the dynamic resolution change 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 > > > > Move update_context_from_thread from ff_thread_decode_frame(main > thread) > > to frame_worker_thread(child thread), update the context in child thread > > right after the context was updated to avoid the async issue. > > > > Signed-off-by: Linjie Fu <linjie...@intel.com> > > --- > > Request for Comments, not quite familiar with the constraints. > > Thanks in advance. > > > > libavcodec/internal.h | 5 ++ > > libavcodec/pthread_frame.c | 164 ++++++++++++++++++++++++---------- > ----------- > > 2 files changed, 91 insertions(+), 78 deletions(-) > > > > diff --git a/libavcodec/internal.h b/libavcodec/internal.h > > index 5096ffa..9f4ed0b 100644 > > --- a/libavcodec/internal.h > > +++ b/libavcodec/internal.h > > @@ -162,6 +162,11 @@ typedef struct AVCodecInternal { > > > > void *thread_ctx; > > > > + /** > > + * Main thread AVCodecContext pointer > > + */ > > + void *main_thread; > > + > > DecodeSimpleContext ds; > > DecodeFilterContext filter; > > > > diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c > > index 36ac0ac..be42e98 100644 > > --- a/libavcodec/pthread_frame.c > > +++ b/libavcodec/pthread_frame.c > > @@ -159,82 +159,6 @@ static void async_unlock(FrameThreadContext > *fctx) > > } > > > > /** > > - * Codec worker thread. > > - * > > - * Automatically calls ff_thread_finish_setup() if the codec does > > - * not provide an update_thread_context method, or if the codec returns > > - * before calling it. > > - */ > > -static attribute_align_arg void *frame_worker_thread(void *arg) > > -{ > > - PerThreadContext *p = arg; > > - AVCodecContext *avctx = p->avctx; > > - const AVCodec *codec = avctx->codec; > > - > > - pthread_mutex_lock(&p->mutex); > > - while (1) { > > - while (atomic_load(&p->state) == STATE_INPUT_READY && !p->die) > > - pthread_cond_wait(&p->input_cond, &p->mutex); > > - > > - if (p->die) break; > > - > > - if (!codec->update_thread_context && > THREAD_SAFE_CALLBACKS(avctx)) > > - ff_thread_finish_setup(avctx); > > - > > - /* If a decoder supports hwaccel, then it must call > > ff_get_format(). > > - * Since that call must happen before ff_thread_finish_setup(), the > > - * decoder is required to implement update_thread_context() and > > call > > - * ff_thread_finish_setup() manually. Therefore the above > > - * ff_thread_finish_setup() call did not happen and > > hwaccel_serializing > > - * cannot be true here. */ > > - av_assert0(!p->hwaccel_serializing); > > - > > - /* if the previous thread uses hwaccel then we take the lock to > > ensure > > - * the threads don't run concurrently */ > > - if (avctx->hwaccel) { > > - pthread_mutex_lock(&p->parent->hwaccel_mutex); > > - p->hwaccel_serializing = 1; > > - } > > - > > - av_frame_unref(p->frame); > > - p->got_frame = 0; > > - p->result = codec->decode(avctx, p->frame, &p->got_frame, &p- > >avpkt); > > - > > - 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 " > > - "free the frame on failure. This is a bug, please > > report it.\n"); > > - av_frame_unref(p->frame); > > - } > > - > > - if (atomic_load(&p->state) == STATE_SETTING_UP) > > - ff_thread_finish_setup(avctx); > > - > > - if (p->hwaccel_serializing) { > > - p->hwaccel_serializing = 0; > > - pthread_mutex_unlock(&p->parent->hwaccel_mutex); > > - } > > - > > - if (p->async_serializing) { > > - p->async_serializing = 0; > > - > > - async_unlock(p->parent); > > - } > > - > > - pthread_mutex_lock(&p->progress_mutex); > > - > > - atomic_store(&p->state, STATE_INPUT_READY); > > - > > - pthread_cond_broadcast(&p->progress_cond); > > - pthread_cond_signal(&p->output_cond); > > - pthread_mutex_unlock(&p->progress_mutex); > > - } > > - pthread_mutex_unlock(&p->mutex); > > - > > - return NULL; > > -} > > - > > -/** > > * Update the next thread's AVCodecContext with values from the > reference thread's context. > > * > > * @param dst The destination context. > > @@ -313,6 +237,89 @@ FF_ENABLE_DEPRECATION_WARNINGS > > return err; > > } > > > > + > > + > > +/** > > + * Codec worker thread. > > + * > > + * Automatically calls ff_thread_finish_setup() if the codec does > > + * not provide an update_thread_context method, or if the codec returns > > + * before calling it. > > + */ > > +static attribute_align_arg void *frame_worker_thread(void *arg) > > +{ > > + PerThreadContext *p = arg; > > + AVCodecContext *avctx = p->avctx; > > + const AVCodec *codec = avctx->codec; > > + > > + pthread_mutex_lock(&p->mutex); > > + while (1) { > > + while (atomic_load(&p->state) == STATE_INPUT_READY && !p->die) > > + pthread_cond_wait(&p->input_cond, &p->mutex); > > + > > + if (p->die) break; > > + > > + if (!codec->update_thread_context && > THREAD_SAFE_CALLBACKS(avctx)) > > + ff_thread_finish_setup(avctx); > > + > > + /* If a decoder supports hwaccel, then it must call > > ff_get_format(). > > + * Since that call must happen before ff_thread_finish_setup(), the > > + * decoder is required to implement update_thread_context() and > call > > + * ff_thread_finish_setup() manually. Therefore the above > > + * ff_thread_finish_setup() call did not happen and > hwaccel_serializing > > + * cannot be true here. */ > > + av_assert0(!p->hwaccel_serializing); > > + > > + /* if the previous thread uses hwaccel then we take the lock to > ensure > > + * the threads don't run concurrently */ > > + if (avctx->hwaccel) { > > + pthread_mutex_lock(&p->parent->hwaccel_mutex); > > + p->hwaccel_serializing = 1; > > + } > > + > > + av_frame_unref(p->frame); > > + p->got_frame = 0; > > + p->result = codec->decode(avctx, p->frame, &p->got_frame, &p- > >avpkt); > > + > > + if (p->avctx->internal->main_thread) > > + update_context_from_thread((AVCodecContext *)p->avctx- > >internal->main_thread, > > + > > p->avctx, 1); > > + > > + > > + 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 " > > + "free the frame on failure. This is a bug, please > > report it.\n"); > > + av_frame_unref(p->frame); > > + } > > + > > + if (atomic_load(&p->state) == STATE_SETTING_UP) > > + ff_thread_finish_setup(avctx); > > + > > + if (p->hwaccel_serializing) { > > + p->hwaccel_serializing = 0; > > + pthread_mutex_unlock(&p->parent->hwaccel_mutex); > > + } > > + > > + if (p->async_serializing) { > > + p->async_serializing = 0; > > + > > + async_unlock(p->parent); > > + } > > + > > + pthread_mutex_lock(&p->progress_mutex); > > + > > + atomic_store(&p->state, STATE_INPUT_READY); > > + > > + pthread_cond_broadcast(&p->progress_cond); > > + pthread_cond_signal(&p->output_cond); > > + pthread_mutex_unlock(&p->progress_mutex); > > + } > > + pthread_mutex_unlock(&p->mutex); > > +: > > + return NULL; > > +} > > + > > Please don't move the entire function around, as it makes it > impossible to spot any differences in the function itself. Instead, > use a forward declaration of whichever function you want to call, so > the diff is more clear. > Thanks, updated to make it easier for review. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
