On Thu, Aug 17, 2023 at 12:42 AM Rémi Denis-Courmont <r...@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@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ 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".
