[FFmpeg-devel] [PATCH v3 1/3] avcodec: make a local copy of executor
Nuo Mi
nuomi2021 at gmail.com
Wed Oct 2 04:46:37 EEST 2024
On Wed, Oct 2, 2024 at 12:31 AM James Almer <jamrial at gmail.com> wrote:
> On 10/1/2024 10:54 AM, Nuo Mi wrote:
> > We still need several refactors to improve the current VVC decoder's
> performance,
> > which will frequently break the API/ABI. To mitigate this, we've copied
> the executor from
> > avutil to avcodec. Once the API/ABI is stable, we will move this class
> back to avutil
> > ---
> > libavcodec/Makefile | 1 +
> > libavcodec/executor.c | 221 ++++++++++++++++++++++++++++++++++++++++
> > libavcodec/executor.h | 73 +++++++++++++
> > libavcodec/vvc/thread.c | 8 +-
> > 4 files changed, 299 insertions(+), 4 deletions(-)
> > create mode 100644 libavcodec/executor.c
> > create mode 100644 libavcodec/executor.h
> >
> > diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> > index a4fcce3b42..da1a1aa945 100644
> > --- a/libavcodec/Makefile
> > +++ b/libavcodec/Makefile
> > @@ -43,6 +43,7 @@ OBJS = ac3_parser.o
> \
> > dirac.o
> \
> > dv_profile.o
> \
> > encode.o
> \
> > + executor.o
> \
> > get_buffer.o
> \
> > imgconvert.o
> \
> > jni.o
> \
> > diff --git a/libavcodec/executor.c b/libavcodec/executor.c
> > new file mode 100644
> > index 0000000000..f8fc7c33ab
> > --- /dev/null
> > +++ b/libavcodec/executor.c
> > @@ -0,0 +1,221 @@
> > +/*
> > + * Copyright (C) 2024 Nuo Mi
> > + *
> > + * This file is part of FFmpeg.
> > + *
> > + * FFmpeg is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; either
> > + * version 2.1 of the License, or (at your option) any later version.
> > + *
> > + * FFmpeg is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with FFmpeg; if not, write to the Free Software
> > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> 02110-1301 USA
> > + */
> > +
> > +#include "config.h"
> > +
> > +#include <stdbool.h>
> > +
> > +#include "libavutil/mem.h"
> > +#include "libavutil/thread.h"
> > +
> > +#include "executor.h"
> > +
> > +#if !HAVE_THREADS
> > +
> > +#define ExecutorThread char
> > +
> > +#define executor_thread_create(t, a, s, ar) 0
> > +#define executor_thread_join(t, r) do {} while(0)
> > +
> > +#else
> > +
> > +#define ExecutorThread pthread_t
> > +
> > +#define executor_thread_create(t, a, s, ar) pthread_create(t, a,
> s, ar)
> > +#define executor_thread_join(t, r) pthread_join(t, r)
> > +
> > +#endif //!HAVE_THREADS
> > +
> > +typedef struct ThreadInfo {
> > + AVExecutor *e;
> > + ExecutorThread thread;
> > +} ThreadInfo;
> > +
> > +struct AVExecutor {
> > + AVTaskCallbacks cb;
> > + int thread_count;
> > + bool recursive;
> > +
> > + ThreadInfo *threads;
> > + uint8_t *local_contexts;
> > +
> > + AVMutex lock;
> > + AVCond cond;
> > + int die;
> > +
> > + AVTask *tasks;
> > +};
> > +
> > +static AVTask* remove_task(AVTask **prev, AVTask *t)
> > +{
> > + *prev = t->next;
> > + t->next = NULL;
> > + return t;
> > +}
> > +
> > +static void add_task(AVTask **prev, AVTask *t)
> > +{
> > + t->next = *prev;
> > + *prev = t;
> > +}
> > +
> > +static int run_one_task(AVExecutor *e, void *lc)
> > +{
> > + AVTaskCallbacks *cb = &e->cb;
> > + AVTask **prev;
> > +
> > + for (prev = &e->tasks; *prev && !cb->ready(*prev, cb->user_data);
> prev = &(*prev)->next)
> > + /* nothing */;
> > + if (*prev) {
> > + AVTask *t = remove_task(prev, *prev);
> > + if (e->thread_count > 0)
> > + ff_mutex_unlock(&e->lock);
> > + cb->run(t, lc, cb->user_data);
> > + if (e->thread_count > 0)
> > + ff_mutex_lock(&e->lock);
> > + return 1;
> > + }
> > + return 0;
> > +}
> > +
> > +#if HAVE_THREADS
> > +static void *executor_worker_task(void *data)
> > +{
> > + ThreadInfo *ti = (ThreadInfo*)data;
> > + AVExecutor *e = ti->e;
> > + void *lc = e->local_contexts + (ti - e->threads) *
> e->cb.local_context_size;
> > +
> > + ff_mutex_lock(&e->lock);
> > + while (1) {
> > + if (e->die) break;
> > +
> > + if (!run_one_task(e, lc)) {
> > + //no task in one loop
> > + ff_cond_wait(&e->cond, &e->lock);
> > + }
> > + }
> > + ff_mutex_unlock(&e->lock);
> > + return NULL;
> > +}
> > +#endif
> > +
> > +static void executor_free(AVExecutor *e, const int has_lock, const int
> has_cond)
> > +{
> > + if (e->thread_count) {
> > + //signal die
> > + ff_mutex_lock(&e->lock);
> > + e->die = 1;
> > + ff_cond_broadcast(&e->cond);
> > + ff_mutex_unlock(&e->lock);
> > +
> > + for (int i = 0; i < e->thread_count; i++)
> > + executor_thread_join(e->threads[i].thread, NULL);
> > + }
> > + if (has_cond)
> > + ff_cond_destroy(&e->cond);
> > + if (has_lock)
> > + ff_mutex_destroy(&e->lock);
> > +
> > + av_free(e->threads);
> > + av_free(e->local_contexts);
> > +
> > + av_free(e);
> > +}
> > +
> > +AVExecutor* ff_executor_alloc(const AVTaskCallbacks *cb, int
> thread_count)
> > +{
> > + AVExecutor *e;
> > + int has_lock = 0, has_cond = 0;
> > + if (!cb || !cb->user_data || !cb->ready || !cb->run ||
> !cb->priority_higher)
> > + return NULL;
> > +
> > + e = av_mallocz(sizeof(*e));
> > + if (!e)
> > + return NULL;
> > + e->cb = *cb;
> > +
> > + e->local_contexts = av_calloc(FFMAX(thread_count, 1),
> e->cb.local_context_size);
> > + if (!e->local_contexts)
> > + goto free_executor;
> > +
> > + e->threads = av_calloc(FFMAX(thread_count, 1), sizeof(*e->threads));
> > + if (!e->threads)
> > + goto free_executor;
> > +
> > + if (!thread_count)
> > + return e;
> > +
> > + has_lock = !ff_mutex_init(&e->lock, NULL);
> > + has_cond = !ff_cond_init(&e->cond, NULL);
> > +
> > + if (!has_lock || !has_cond)
> > + goto free_executor;
> > +
> > + for (/* nothing */; e->thread_count < thread_count;
> e->thread_count++) {
> > + ThreadInfo *ti = e->threads + e->thread_count;
> > + ti->e = e;
> > + if (executor_thread_create(&ti->thread, NULL,
> executor_worker_task, ti))
> > + goto free_executor;
> > + }
> > + return e;
> > +
> > +free_executor:
> > + executor_free(e, has_lock, has_cond);
> > + return NULL;
> > +}
> > +
> > +void ff_executor_free(AVExecutor **executor)
> > +{
> > + int thread_count;
> > +
> > + if (!executor || !*executor)
> > + return;
> > + thread_count = (*executor)->thread_count;
> > + executor_free(*executor, thread_count, thread_count);
> > + *executor = NULL;
> > +}
> > +
> > +void ff_executor_execute(AVExecutor *e, AVTask *t)
> > +{
> > + AVTaskCallbacks *cb = &e->cb;
> > + AVTask **prev;
> > +
> > + if (e->thread_count)
> > + ff_mutex_lock(&e->lock);
> > + if (t) {
> > + for (prev = &e->tasks; *prev && cb->priority_higher(*prev, t);
> prev = &(*prev)->next)
> > + /* nothing */;
> > + add_task(prev, t);
> > + }
> > + if (e->thread_count) {
> > + ff_cond_signal(&e->cond);
> > + ff_mutex_unlock(&e->lock);
> > + }
> > +
> > + if (!e->thread_count || !HAVE_THREADS) {
> > + if (e->recursive)
> > + return;
> > + e->recursive = true;
> > + // We are running in a single-threaded environment, so we must
> handle all tasks ourselves
> > + while (run_one_task(e, e->local_contexts))
> > + /* nothing */;
> > + e->recursive = false;
> > + }
> > +}
> > diff --git a/libavcodec/executor.h b/libavcodec/executor.h
> > new file mode 100644
> > index 0000000000..05d4b1e189
> > --- /dev/null
> > +++ b/libavcodec/executor.h
> > @@ -0,0 +1,73 @@
> > +/*
> > + * Copyright (C) 2024 Nuo Mi
> > + *
> > + * This file is part of FFmpeg.
> > + *
> > + * FFmpeg is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; either
> > + * version 2.1 of the License, or (at your option) any later version.
> > + *
> > + * FFmpeg is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with FFmpeg; if not, write to the Free Software
> > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> 02110-1301 USA
> > + */
> > +
> > +/*
> > + * We still need several refactors to improve the current VVC decoder's
> performance,
> > + * which will frequently break the API/ABI. To mitigate this, we've
> copied the executor from
> > + * avutil to avcodec. Once the API/ABI is stable, we will move this
> class back to avutil
> > + */
> > +
> > +#ifndef AVCODEC_EXECUTOR_H
> > +#define AVCODEC_EXECUTOR_H
> > +
> > +typedef struct AVExecutor AVExecutor;
> > +typedef struct AVTask AVTask;
> > +
> > +struct AVTask {
> > + AVTask *next;
> > +};
> > +
> > +typedef struct AVTaskCallbacks {
>
> Should probably use a different namespace for this header, to ensure it
> doesn't conflict with the lavu one. So just prefix everything with FF
> instead of AV.
>
Sure. It is fixed by v4.
>
> > + void *user_data;
> > +
> > + int local_context_size;
> > +
> > + // return 1 if a's priority > b's priority
> > + int (*priority_higher)(const AVTask *a, const AVTask *b);
> > +
> > + // task is ready for run
> > + int (*ready)(const AVTask *t, void *user_data);
> > +
> > + // run the task
> > + int (*run)(AVTask *t, void *local_context, void *user_data);
> > +} AVTaskCallbacks;
> > +
> > +/**
> > + * Alloc executor
> > + * @param callbacks callback structure for executor
> > + * @param thread_count worker thread number, 0 for run on caller's
> thread directly
> > + * @return return the executor
> > + */
> > +AVExecutor* ff_executor_alloc(const AVTaskCallbacks *callbacks, int
> thread_count);
> > +
> > +/**
> > + * Free executor
> > + * @param e pointer to executor
> > + */
> > +void ff_executor_free(AVExecutor **e);
> > +
> > +/**
> > + * Add task to executor
> > + * @param e pointer to executor
> > + * @param t pointer to task. If NULL, it will wakeup one work thread
> > + */
> > +void ff_executor_execute(AVExecutor *e, AVTask *t);
> > +
> > +#endif //AVCODEC_EXECUTOR_H
> > diff --git a/libavcodec/vvc/thread.c b/libavcodec/vvc/thread.c
> > index 86a7753c6a..72f5c51382 100644
> > --- a/libavcodec/vvc/thread.c
> > +++ b/libavcodec/vvc/thread.c
> > @@ -22,7 +22,7 @@
> >
> > #include <stdatomic.h>
> >
> > -#include "libavutil/executor.h"
> > +#include "libavcodec/executor.h"
> > #include "libavutil/mem.h"
> > #include "libavutil/thread.h"
> >
> > @@ -109,7 +109,7 @@ static void add_task(VVCContext *s, VVCTask *t)
> >
> > atomic_fetch_add(&ft->nb_scheduled_tasks, 1);
> >
> > - av_executor_execute(s->executor, &t->u.task);
> > + ff_executor_execute(s->executor, &t->u.task);
> > }
> >
> > static void task_init(VVCTask *t, VVCTaskStage stage, VVCFrameContext
> *fc, const int rx, const int ry)
> > @@ -692,12 +692,12 @@ AVExecutor* ff_vvc_executor_alloc(VVCContext *s,
> const int thread_count)
> > task_ready,
> > task_run,
> > };
> > - return av_executor_alloc(&callbacks, thread_count);
> > + return ff_executor_alloc(&callbacks, thread_count);
> > }
> >
> > void ff_vvc_executor_free(AVExecutor **e)
> > {
> > - av_executor_free(e);
> > + ff_executor_free(e);
> > }
> >
> > void ff_vvc_frame_thread_free(VVCFrameContext *fc)
>
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