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/*
*
* 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
*/
/**
* @file
* Libavfilter multithreading support
*/
#include "config.h"
#include "libavutil/common.h"
#include "libavutil/cpu.h"
#include "libavutil/mem.h"
#include "avfilter.h"
#include "internal.h"
#include "thread.h"
#if HAVE_PTHREADS
#include <pthread.h>
#elif HAVE_W32THREADS
#include "compat/w32pthreads.h"
#endif
typedef struct ThreadContext {
AVFilterGraph *graph;
int nb_threads;
pthread_t *workers;
action_func *func;
/* per-execute perameters */
AVFilterContext *ctx;
void *arg;
int *rets;
int nb_rets;
int nb_jobs;
pthread_cond_t last_job_cond;
pthread_cond_t current_job_cond;
pthread_mutex_t current_job_lock;
int current_job;
int done;
} ThreadContext;
static void* attribute_align_arg worker(void *v)
{
ThreadContext *c = v;
int our_job = c->nb_jobs;
int nb_threads = c->nb_threads;
int self_id;
pthread_mutex_lock(&c->current_job_lock);
self_id = c->current_job++;
for (;;) {
while (our_job >= c->nb_jobs) {
if (c->current_job == nb_threads + c->nb_jobs)
pthread_cond_signal(&c->last_job_cond);
pthread_cond_wait(&c->current_job_cond, &c->current_job_lock);
our_job = self_id;
if (c->done) {
pthread_mutex_unlock(&c->current_job_lock);
return NULL;
}
}
pthread_mutex_unlock(&c->current_job_lock);
c->rets[our_job % c->nb_rets] = c->func(c->ctx, c->arg, our_job, c->nb_jobs);
pthread_mutex_lock(&c->current_job_lock);
our_job = c->current_job++;
}
}
static void slice_thread_uninit(ThreadContext *c)
{
int i;
pthread_mutex_lock(&c->current_job_lock);
c->done = 1;
pthread_cond_broadcast(&c->current_job_cond);
pthread_mutex_unlock(&c->current_job_lock);
for (i = 0; i < c->nb_threads; i++)
pthread_join(c->workers[i], NULL);
pthread_mutex_destroy(&c->current_job_lock);
pthread_cond_destroy(&c->current_job_cond);
pthread_cond_destroy(&c->last_job_cond);
av_freep(&c->workers);
}
static void slice_thread_park_workers(ThreadContext *c)
{
pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);
pthread_mutex_unlock(&c->current_job_lock);
}
static int thread_execute(AVFilterContext *ctx, action_func *func,
void *arg, int *ret, int nb_jobs)
{
ThreadContext *c = ctx->graph->internal->thread;
int dummy_ret;
if (nb_jobs <= 0)
return 0;
pthread_mutex_lock(&c->current_job_lock);
c->current_job = c->nb_threads;
c->nb_jobs = nb_jobs;
c->ctx = ctx;
c->arg = arg;
c->func = func;
if (ret) {
c->rets = ret;
c->nb_rets = nb_jobs;
} else {
c->rets = &dummy_ret;
c->nb_rets = 1;
}
pthread_cond_broadcast(&c->current_job_cond);
slice_thread_park_workers(c);
return 0;
}
static int thread_init(ThreadContext *c, int nb_threads)
{
int i, ret;
if (!nb_threads) {
int nb_cpus = av_cpu_count();
// use number of cores + 1 as thread count if there is more than one
if (nb_cpus > 1)
nb_threads = nb_cpus + 1;
else
nb_threads = 1;
}
if (nb_threads <= 1)
return 1;
c->nb_threads = nb_threads;
c->workers = av_mallocz(sizeof(*c->workers) * nb_threads);
if (!c->workers)
return AVERROR(ENOMEM);
c->current_job = 0;
c->nb_jobs = 0;
c->done = 0;
pthread_cond_init(&c->current_job_cond, NULL);
pthread_cond_init(&c->last_job_cond, NULL);
pthread_mutex_init(&c->current_job_lock, NULL);
pthread_mutex_lock(&c->current_job_lock);
for (i = 0; i < nb_threads; i++) {
ret = pthread_create(&c->workers[i], NULL, worker, c);
if (ret) {
pthread_mutex_unlock(&c->current_job_lock);
c->nb_threads = i;
slice_thread_uninit(c);
return AVERROR(ret);
}
}
slice_thread_park_workers(c);
return c->nb_threads;
}
int ff_graph_thread_init(AVFilterGraph *graph)
{
int ret;
#if HAVE_W32THREADS
w32thread_init();
#endif
if (graph->nb_threads == 1) {
graph->thread_type = 0;
return 0;
}
graph->internal->thread = av_mallocz(sizeof(ThreadContext));
if (!graph->internal->thread)
return AVERROR(ENOMEM);
ret = thread_init(graph->internal->thread, graph->nb_threads);
if (ret <= 1) {
av_freep(&graph->internal->thread);
graph->thread_type = 0;
graph->nb_threads = 1;
return (ret < 0) ? ret : 0;
}
graph->nb_threads = ret;
graph->internal->thread_execute = thread_execute;
return 0;
}
void ff_graph_thread_free(AVFilterGraph *graph)
{
if (graph->internal->thread)
slice_thread_uninit(graph->internal->thread);
av_freep(&graph->internal->thread);
}
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