[FFmpeg-devel] [PATCH v4] vvcdec: add thread executor
Nuo Mi
nuomi2021 at gmail.com
Tue Aug 22 15:03:30 EEST 2023
On Thu, Aug 17, 2023 at 12:42 AM Rémi Denis-Courmont <remi at remlab.net>
wrote:
> Le tiistaina 15. elokuuta 2023, 17.50.13 EEST Nuo Mi a écrit :
> > The executor design pattern was inroduced by java
> > <
> https://docs.oracle.com/en/java/javase/20/docs/api/java.base/java/util/conc
> > urrent/Executor.html> it also adapted by python
> > <https://docs.python.org/3/library/concurrent.futures.html>
> > Compared to handcrafted thread pool management, it greatly simplifies the
> > thread code. ---
> > libavutil/Makefile | 2 +
> > libavutil/executor.c | 201 +++++++++++++++++++++++++++++++++++++++++++
> > libavutil/executor.h | 67 +++++++++++++++
> > 3 files changed, 270 insertions(+)
> > create mode 100644 libavutil/executor.c
> > create mode 100644 libavutil/executor.h
> >
> > diff --git a/libavutil/Makefile b/libavutil/Makefile
> > index 7828c94dc5..4711f8cde8 100644
> > --- a/libavutil/Makefile
> > +++ b/libavutil/Makefile
> > @@ -31,6 +31,7 @@ HEADERS = adler32.h
>
> > \ encryption_info.h
>
> > \ error.h \
> eval.h
> > \ +
> > executor.h \ fifo.h
>
> > \ file.h
>
> > \ frame.h
>
> > \ @@ -127,6 +128,7 @@ OBJS = adler32.o
>
> > \ encryption_info.o
>
> > \ error.o
>
> > \ eval.o
>
> > \ + executor.o
>
> > \ fifo.o
>
> > \ file.o
> \
> > file_open.o \ diff
> > --git a/libavutil/executor.c b/libavutil/executor.c
> > new file mode 100644
> > index 0000000000..6b47ba0bf2
> > --- /dev/null
> > +++ b/libavutil/executor.c
> > @@ -0,0 +1,201 @@
> > +/*
> > + * Copyright (C) 2023 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 "internal.h"
> > +#include "mem.h"
> > +#include "thread.h"
> > +
> > +#include "executor.h"
> > +
> > +#if !HAVE_THREADS
> > +#define pthread_create(t, a, s, ar) 0
>
> Err, this should probably return an error value, e.g. ENOSYS or ENOTSUP.
>
> > +#define pthread_join(t, r) do {} while(0)
>
> ...and this should be an unreachable(), assert(0), abort() or something
> along
> those lines.
>
> > +
> > +#define pthread_cond_init(c, a) 0
> > +#define pthread_cond_broadcast(c) do {} while(0)
> > +#define pthread_cond_signal(c) do {} while(0)
> > +#define pthread_cond_wait(c, m) do {} while(0)
> > +#define pthread_cond_destroy(c) do {} while(0)
> > +
> > +#define pthread_mutex_init(m, a) 0
> > +#define pthread_mutex_lock(l) do {} while(0)
> > +#define pthread_mutex_unlock(l) do {} while(0)
> > +#define pthread_mutex_destroy(l) do {} while(0)
> > +#endif
> > +
> > +typedef struct ThreadInfo {
> > + AVExecutor *e;
> > + pthread_t thread;
>
> Does this even work if !HAVE_THREAD ?
Yes. The definition provided by the following include chain:
"mem.h"->"avutil.h"->"common.h"->"<stdlib.h>"->"<sys/types.h>"->"<bits/pthreadtypes.h>"
>
> > +} ThreadInfo;
> > +
> > +struct AVExecutor {
> > + AVTaskCallbacks cb;
> > + int thread_count;
> > +
> > + ThreadInfo *threads;
> > + uint8_t *local_contexts;
> > +
> > + pthread_mutex_t lock;
> > + pthread_cond_t 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);
> > + pthread_mutex_unlock(&e->lock);
> > + cb->run(t, lc, cb->user_data);
> > + pthread_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; +
> > + pthread_mutex_lock(&e->lock);
> > + while (1) {
> > + if (e->die) break;
> > +
> > + if (!run_one_task(e, lc)) {
> > + //no task in one loop
> > + pthread_cond_wait(&e->cond, &e->lock);
> > + }
> > + }
> > + pthread_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
> > + pthread_mutex_lock(&e->lock);
> > + e->die = 1;
> > + pthread_cond_broadcast(&e->cond);
> > + pthread_mutex_unlock(&e->lock);
> > +
> > + for (int i = 0; i < e->thread_count; i++)
> > + pthread_join(e->threads[i].thread, NULL);
> > + }
> > + if (has_cond)
> > + pthread_cond_destroy(&e->cond);
> > + if (has_lock)
> > + pthread_mutex_destroy(&e->lock);
> > +
> > + av_free(e->threads);
> > + av_free(e->local_contexts);
> > +
> > + av_free(e);
> > +}
> > +
> > +AVExecutor* av_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_calloc(1, sizeof(*e));
> > + if (!e)
> > + return NULL;
> > + e->cb = *cb;
> > +
> > + e->local_contexts = av_calloc(thread_count,
> e->cb.local_context_size);
> > + if (!e->local_contexts)
> > + goto free_executor;
> > +
> > + e->threads = av_calloc(thread_count, sizeof(*e->threads));
> > + if (!e->threads)
> > + goto free_executor;
> > +
> > + has_lock = !pthread_mutex_init(&e->lock, NULL);
> > + has_cond = !pthread_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 (pthread_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 av_executor_free(AVExecutor **executor)
> > +{
> > + if (!executor || !*executor)
> > + return;
> > + executor_free(*executor, 1, 1);
> > + *executor = NULL;
> > +}
> > +
> > +void av_executor_execute(AVExecutor *e, AVTask *t)
> > +{
> > + AVTaskCallbacks *cb = &e->cb;
> > + AVTask **prev;
> > +
> > + pthread_mutex_lock(&e->lock);
> > + if (t) {
> > + for (prev = &e->tasks; *prev && cb->priority_higher(*prev, t);
> prev
> > = &(*prev)->next) + /* nothing */;
> > + add_task(prev, t);
> > + }
> > + pthread_cond_signal(&e->cond);
> > + pthread_mutex_unlock(&e->lock);
> > +
> > +#if !HAVE_THREADS
> > + // We are running in a single-threaded environment, so we must
> handle
> > all tasks ourselves
> > + while (run_one_task(e, e->local_contexts))
> > + /* nothing */;
> > +#endif
> > +}
> > diff --git a/libavutil/executor.h b/libavutil/executor.h
> > new file mode 100644
> > index 0000000000..c3fe44bd0e
> > --- /dev/null
> > +++ b/libavutil/executor.h
> > @@ -0,0 +1,67 @@
> > +/*
> > + * Copyright (C) 2023 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 + */
> > +
> > +#ifndef AVUTIL_EXECUTOR_H
> > +#define AVUTIL_EXECUTOR_H
> > +
> > +typedef struct AVExecutor AVExecutor;
> > +typedef struct AVTask AVTask;
> > +
> > +struct AVTask {
> > + AVTask *next;
> > +};
> > +
> > +typedef struct AVTaskCallbacks {
> > + 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 strucutre for executor
> > + * @param thread_count worker thread number
> > + * @return return the executor
> > + */
> > +AVExecutor* av_executor_alloc(const AVTaskCallbacks *callbacks, int
> > thread_count); +
> > +/**
> > + * Free executor
> > + * @param e pointer to executor
> > + */
> > +void av_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 av_executor_execute(AVExecutor *e, AVTask *t);
> > +
> > +#endif //AVUTIL_EXECUTOR_H
>
>
> --
> Rémi Denis-Courmont
> http://www.remlab.net/
>
>
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
>
More information about the ffmpeg-devel
mailing list