| Message ID | 20210323123554.1370260-3-andreas.rheinhardt@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [FFmpeg-devel,v2,1/4] avcodec/pthread_frame: Factor initializing single thread out | expand |
| Context | Check | Description |
|---|---|---|
| andriy/x86_make | success | Make finished |
| andriy/x86_make_fate | success | Make fate finished |
| andriy/PPC64_make | success | Make finished |
| andriy/PPC64_make_fate | success | Make fate finished |
Andreas Rheinhardt: > Up until now, initializing the mutexes/condition variables wasn't > checked by ff_frame_thread_init(). This commit changes this. > > Given that it is not documented to be save to destroy a zeroed but > otherwise uninitialized mutex/condition variable, one has to choose > between two approaches: Either one duplicates the code to free them > in ff_frame_thread_init() in case of errors or one records which have > been successfully initialized. This commit takes the latter approach: > For each of the two structures with mutexes/condition variables > an array containing the offsets of the members to initialize is added. > Said array is used both for initializing and freeing and the only thing > that needs to be recorded is how many of these have been successfully > initialized. > > Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> > --- > libavcodec/pthread_frame.c | 98 ++++++++++++++++++++++++++++---------- > 1 file changed, 73 insertions(+), 25 deletions(-) > > diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c > index db2f0cb3d2..1c17d8c3b6 100644 > --- a/libavcodec/pthread_frame.c > +++ b/libavcodec/pthread_frame.c > @@ -78,6 +78,7 @@ typedef struct PerThreadContext { > > pthread_t thread; > int thread_init; > + unsigned pthread_init_cnt;///< Number of successfully initialized mutexes/conditions > pthread_cond_t input_cond; ///< Used to wait for a new packet from the main thread. > pthread_cond_t progress_cond; ///< Used by child threads to wait for progress to change. > pthread_cond_t output_cond; ///< Used by the main thread to wait for frames to finish. > @@ -126,6 +127,7 @@ typedef struct FrameThreadContext { > PerThreadContext *threads; ///< The contexts for each thread. > PerThreadContext *prev_thread; ///< The last thread submit_packet() was called on. > > + unsigned pthread_init_cnt; ///< Number of successfully initialized mutexes/conditions > pthread_mutex_t buffer_mutex; ///< Mutex used to protect get/release_buffer(). > /** > * This lock is used for ensuring threads run in serial when hwaccel > @@ -680,6 +682,59 @@ static void park_frame_worker_threads(FrameThreadContext *fctx, int thread_count > async_lock(fctx); > } > > +#define SENTINEL 0 // This forbids putting a mutex/condition variable at the front. > +#define OFFSET_ARRAY(...) __VA_ARGS__, SENTINEL > +#define DEFINE_OFFSET_ARRAY(type, name, mutexes, conds) \ > +static const unsigned name ## _offsets[] = { offsetof(type, pthread_init_cnt),\ > + OFFSET_ARRAY mutexes, \ > + OFFSET_ARRAY conds } > + > +#define OFF(member) offsetof(FrameThreadContext, member) > +DEFINE_OFFSET_ARRAY(FrameThreadContext, thread_ctx, > + (OFF(buffer_mutex), OFF(hwaccel_mutex), OFF(async_mutex)), > + (OFF(async_cond))); > +#undef OFF > + > +#define OFF(member) offsetof(PerThreadContext, member) > +DEFINE_OFFSET_ARRAY(PerThreadContext, per_thread, > + (OFF(progress_mutex), OFF(mutex)), > + (OFF(input_cond), OFF(progress_cond), OFF(output_cond))); > +#undef OFF > + > +static av_cold void free_pthread(void *obj, const unsigned offsets[]) > +{ > + unsigned cnt = *(unsigned*)((char*)obj + offsets[0]); > + const unsigned *cur_offset = offsets; > + > + for (; *(++cur_offset) != SENTINEL && cnt; cnt--) > + pthread_mutex_destroy((pthread_mutex_t*)((char*)obj + *cur_offset)); > + for (; *(++cur_offset) != SENTINEL && cnt; cnt--) > + pthread_cond_destroy ((pthread_cond_t *)((char*)obj + *cur_offset)); > +} > + > +static av_cold int init_pthread(void *obj, const unsigned offsets[]) > +{ > + const unsigned *cur_offset = offsets; > + unsigned cnt = 0; > + int err; > + > +#define PTHREAD_INIT_LOOP(type, max_idx) \ > + for (; *(++cur_offset) != SENTINEL; cnt++) { \ > + pthread_ ## type ## _t *dst = (void*)((char*)obj + *cur_offset); \ > + err = pthread_ ## type ## _init(dst, NULL); \ > + if (err) { \ > + err = AVERROR(err); \ > + goto fail; \ > + } \ > + } > + PTHREAD_INIT_LOOP(mutex, MAX_MUTEX_IDX(offsets)) > + PTHREAD_INIT_LOOP(cond, MAX_COND_IDX(offsets)) MAX_MUTEX/COND_IDX is a remnant of an earlier version. Removed locally. > + > +fail: > + *(unsigned*)((char*)obj + offsets[0]) = cnt; > + return err; > +} > + > void ff_frame_thread_free(AVCodecContext *avctx, int thread_count) > { > FrameThreadContext *fctx = avctx->internal->thread_ctx; > @@ -739,21 +794,14 @@ void ff_frame_thread_free(AVCodecContext *avctx, int thread_count) > > av_frame_free(&p->frame); > > - pthread_mutex_destroy(&p->mutex); > - pthread_mutex_destroy(&p->progress_mutex); > - pthread_cond_destroy(&p->input_cond); > - pthread_cond_destroy(&p->progress_cond); > - pthread_cond_destroy(&p->output_cond); > + free_pthread(p, per_thread_offsets); > av_packet_free(&p->avpkt); > > av_freep(&p->avctx); > } > > av_freep(&fctx->threads); > - pthread_mutex_destroy(&fctx->buffer_mutex); > - pthread_mutex_destroy(&fctx->hwaccel_mutex); > - pthread_mutex_destroy(&fctx->async_mutex); > - pthread_cond_destroy(&fctx->async_cond); > + free_pthread(fctx, thread_ctx_offsets); > > av_freep(&avctx->internal->thread_ctx); > > @@ -780,12 +828,6 @@ static av_cold int init_thread(PerThreadContext *p, int *threads_to_free, > * ff_frame_thread_free in case of errors. */ > (*threads_to_free)++; > > - pthread_mutex_init(&p->mutex, NULL); > - pthread_mutex_init(&p->progress_mutex, NULL); > - pthread_cond_init(&p->input_cond, NULL); > - pthread_cond_init(&p->progress_cond, NULL); > - pthread_cond_init(&p->output_cond, NULL); > - > p->parent = fctx; > p->avctx = copy; > > @@ -810,6 +852,10 @@ static av_cold int init_thread(PerThreadContext *p, int *threads_to_free, > } > } > > + err = init_pthread(p, per_thread_offsets); > + if (err < 0) > + return err; > + > if (!(p->frame = av_frame_alloc()) || > !(p->avpkt = av_packet_alloc())) > return AVERROR(ENOMEM); > @@ -846,7 +892,7 @@ int ff_frame_thread_init(AVCodecContext *avctx) > const AVCodec *codec = avctx->codec; > AVCodecContext *src = avctx; > FrameThreadContext *fctx; > - int i, err = 0; > + int err, i = 0; > > if (!thread_count) { > int nb_cpus = av_cpu_count(); > @@ -866,24 +912,26 @@ int ff_frame_thread_init(AVCodecContext *avctx) > if (!fctx) > return AVERROR(ENOMEM); > > - fctx->threads = av_mallocz_array(thread_count, sizeof(PerThreadContext)); > - if (!fctx->threads) { > + err = init_pthread(fctx, thread_ctx_offsets); > + if (err < 0) { > + free_pthread(fctx, thread_ctx_offsets); > av_freep(&avctx->internal->thread_ctx); > - return AVERROR(ENOMEM); > + return err; > } > > - pthread_mutex_init(&fctx->buffer_mutex, NULL); > - pthread_mutex_init(&fctx->hwaccel_mutex, NULL); > - pthread_mutex_init(&fctx->async_mutex, NULL); > - pthread_cond_init(&fctx->async_cond, NULL); > - > fctx->async_lock = 1; > fctx->delaying = 1; > > if (codec->type == AVMEDIA_TYPE_VIDEO) > avctx->delay = src->thread_count - 1; > > - for (i = 0; i < thread_count; ) { > + fctx->threads = av_mallocz_array(thread_count, sizeof(PerThreadContext)); > + if (!fctx->threads) { > + err = AVERROR(ENOMEM); > + goto error; > + } > + > + for (; i < thread_count; ) { > PerThreadContext *p = &fctx->threads[i]; > int first = !i; > >
diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c index db2f0cb3d2..1c17d8c3b6 100644 --- a/libavcodec/pthread_frame.c +++ b/libavcodec/pthread_frame.c @@ -78,6 +78,7 @@ typedef struct PerThreadContext { pthread_t thread; int thread_init; + unsigned pthread_init_cnt;///< Number of successfully initialized mutexes/conditions pthread_cond_t input_cond; ///< Used to wait for a new packet from the main thread. pthread_cond_t progress_cond; ///< Used by child threads to wait for progress to change. pthread_cond_t output_cond; ///< Used by the main thread to wait for frames to finish. @@ -126,6 +127,7 @@ typedef struct FrameThreadContext { PerThreadContext *threads; ///< The contexts for each thread. PerThreadContext *prev_thread; ///< The last thread submit_packet() was called on. + unsigned pthread_init_cnt; ///< Number of successfully initialized mutexes/conditions pthread_mutex_t buffer_mutex; ///< Mutex used to protect get/release_buffer(). /** * This lock is used for ensuring threads run in serial when hwaccel @@ -680,6 +682,59 @@ static void park_frame_worker_threads(FrameThreadContext *fctx, int thread_count async_lock(fctx); } +#define SENTINEL 0 // This forbids putting a mutex/condition variable at the front. +#define OFFSET_ARRAY(...) __VA_ARGS__, SENTINEL +#define DEFINE_OFFSET_ARRAY(type, name, mutexes, conds) \ +static const unsigned name ## _offsets[] = { offsetof(type, pthread_init_cnt),\ + OFFSET_ARRAY mutexes, \ + OFFSET_ARRAY conds } + +#define OFF(member) offsetof(FrameThreadContext, member) +DEFINE_OFFSET_ARRAY(FrameThreadContext, thread_ctx, + (OFF(buffer_mutex), OFF(hwaccel_mutex), OFF(async_mutex)), + (OFF(async_cond))); +#undef OFF + +#define OFF(member) offsetof(PerThreadContext, member) +DEFINE_OFFSET_ARRAY(PerThreadContext, per_thread, + (OFF(progress_mutex), OFF(mutex)), + (OFF(input_cond), OFF(progress_cond), OFF(output_cond))); +#undef OFF + +static av_cold void free_pthread(void *obj, const unsigned offsets[]) +{ + unsigned cnt = *(unsigned*)((char*)obj + offsets[0]); + const unsigned *cur_offset = offsets; + + for (; *(++cur_offset) != SENTINEL && cnt; cnt--) + pthread_mutex_destroy((pthread_mutex_t*)((char*)obj + *cur_offset)); + for (; *(++cur_offset) != SENTINEL && cnt; cnt--) + pthread_cond_destroy ((pthread_cond_t *)((char*)obj + *cur_offset)); +} + +static av_cold int init_pthread(void *obj, const unsigned offsets[]) +{ + const unsigned *cur_offset = offsets; + unsigned cnt = 0; + int err; + +#define PTHREAD_INIT_LOOP(type, max_idx) \ + for (; *(++cur_offset) != SENTINEL; cnt++) { \ + pthread_ ## type ## _t *dst = (void*)((char*)obj + *cur_offset); \ + err = pthread_ ## type ## _init(dst, NULL); \ + if (err) { \ + err = AVERROR(err); \ + goto fail; \ + } \ + } + PTHREAD_INIT_LOOP(mutex, MAX_MUTEX_IDX(offsets)) + PTHREAD_INIT_LOOP(cond, MAX_COND_IDX(offsets)) + +fail: + *(unsigned*)((char*)obj + offsets[0]) = cnt; + return err; +} + void ff_frame_thread_free(AVCodecContext *avctx, int thread_count) { FrameThreadContext *fctx = avctx->internal->thread_ctx; @@ -739,21 +794,14 @@ void ff_frame_thread_free(AVCodecContext *avctx, int thread_count) av_frame_free(&p->frame); - pthread_mutex_destroy(&p->mutex); - pthread_mutex_destroy(&p->progress_mutex); - pthread_cond_destroy(&p->input_cond); - pthread_cond_destroy(&p->progress_cond); - pthread_cond_destroy(&p->output_cond); + free_pthread(p, per_thread_offsets); av_packet_free(&p->avpkt); av_freep(&p->avctx); } av_freep(&fctx->threads); - pthread_mutex_destroy(&fctx->buffer_mutex); - pthread_mutex_destroy(&fctx->hwaccel_mutex); - pthread_mutex_destroy(&fctx->async_mutex); - pthread_cond_destroy(&fctx->async_cond); + free_pthread(fctx, thread_ctx_offsets); av_freep(&avctx->internal->thread_ctx); @@ -780,12 +828,6 @@ static av_cold int init_thread(PerThreadContext *p, int *threads_to_free, * ff_frame_thread_free in case of errors. */ (*threads_to_free)++; - pthread_mutex_init(&p->mutex, NULL); - pthread_mutex_init(&p->progress_mutex, NULL); - pthread_cond_init(&p->input_cond, NULL); - pthread_cond_init(&p->progress_cond, NULL); - pthread_cond_init(&p->output_cond, NULL); - p->parent = fctx; p->avctx = copy; @@ -810,6 +852,10 @@ static av_cold int init_thread(PerThreadContext *p, int *threads_to_free, } } + err = init_pthread(p, per_thread_offsets); + if (err < 0) + return err; + if (!(p->frame = av_frame_alloc()) || !(p->avpkt = av_packet_alloc())) return AVERROR(ENOMEM); @@ -846,7 +892,7 @@ int ff_frame_thread_init(AVCodecContext *avctx) const AVCodec *codec = avctx->codec; AVCodecContext *src = avctx; FrameThreadContext *fctx; - int i, err = 0; + int err, i = 0; if (!thread_count) { int nb_cpus = av_cpu_count(); @@ -866,24 +912,26 @@ int ff_frame_thread_init(AVCodecContext *avctx) if (!fctx) return AVERROR(ENOMEM); - fctx->threads = av_mallocz_array(thread_count, sizeof(PerThreadContext)); - if (!fctx->threads) { + err = init_pthread(fctx, thread_ctx_offsets); + if (err < 0) { + free_pthread(fctx, thread_ctx_offsets); av_freep(&avctx->internal->thread_ctx); - return AVERROR(ENOMEM); + return err; } - pthread_mutex_init(&fctx->buffer_mutex, NULL); - pthread_mutex_init(&fctx->hwaccel_mutex, NULL); - pthread_mutex_init(&fctx->async_mutex, NULL); - pthread_cond_init(&fctx->async_cond, NULL); - fctx->async_lock = 1; fctx->delaying = 1; if (codec->type == AVMEDIA_TYPE_VIDEO) avctx->delay = src->thread_count - 1; - for (i = 0; i < thread_count; ) { + fctx->threads = av_mallocz_array(thread_count, sizeof(PerThreadContext)); + if (!fctx->threads) { + err = AVERROR(ENOMEM); + goto error; + } + + for (; i < thread_count; ) { PerThreadContext *p = &fctx->threads[i]; int first = !i;
Up until now, initializing the mutexes/condition variables wasn't checked by ff_frame_thread_init(). This commit changes this. Given that it is not documented to be save to destroy a zeroed but otherwise uninitialized mutex/condition variable, one has to choose between two approaches: Either one duplicates the code to free them in ff_frame_thread_init() in case of errors or one records which have been successfully initialized. This commit takes the latter approach: For each of the two structures with mutexes/condition variables an array containing the offsets of the members to initialize is added. Said array is used both for initializing and freeing and the only thing that needs to be recorded is how many of these have been successfully initialized. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> --- libavcodec/pthread_frame.c | 98 ++++++++++++++++++++++++++++---------- 1 file changed, 73 insertions(+), 25 deletions(-)