FFmpeg/libavcodec/pthread.c
Ramiro Polla 5e4c7ca224 Add attribute that forces alignment of stack to functions that need it.
Necessary for systems that don't align by default to 16 bytes, required by some
SSE instructions.
Requires GCC >= 4.2.
Based on patch by Gaël Chardon.

Originally committed as revision 10106 to svn://svn.ffmpeg.org/ffmpeg/trunk
2007-08-13 15:28:29 +00:00

169 lines
4.6 KiB
C

/*
* Copyright (c) 2004 Roman Shaposhnik.
*
* Many thanks to Steven M. Schultz for providing clever ideas and
* to Michael Niedermayer <michaelni@gmx.at> for writing initial
* implementation.
*
* 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 <pthread.h>
#include "avcodec.h"
typedef int (action_t)(AVCodecContext *c, void *arg);
typedef struct ThreadContext {
pthread_t *workers;
action_t *func;
void **args;
int *rets;
int rets_count;
int job_count;
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)
{
AVCodecContext *avctx = v;
ThreadContext *c = avctx->thread_opaque;
int our_job = c->job_count;
int thread_count = avctx->thread_count;
int self_id;
pthread_mutex_lock(&c->current_job_lock);
self_id = c->current_job++;
for (;;){
while (our_job >= c->job_count) {
if (c->current_job == thread_count + c->job_count)
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->rets_count] = c->func(avctx, c->args[our_job]);
pthread_mutex_lock(&c->current_job_lock);
our_job = c->current_job++;
}
}
static av_always_inline void avcodec_thread_park_workers(ThreadContext *c, int thread_count)
{
pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);
pthread_mutex_unlock(&c->current_job_lock);
}
void avcodec_thread_free(AVCodecContext *avctx)
{
ThreadContext *c = avctx->thread_opaque;
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<avctx->thread_count; 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_free(c->workers);
av_freep(&avctx->thread_opaque);
}
int avcodec_thread_execute(AVCodecContext *avctx, action_t* func, void **arg, int *ret, int job_count)
{
ThreadContext *c= avctx->thread_opaque;
int dummy_ret;
if (job_count <= 0)
return 0;
pthread_mutex_lock(&c->current_job_lock);
c->current_job = avctx->thread_count;
c->job_count = job_count;
c->args = arg;
c->func = func;
if (ret) {
c->rets = ret;
c->rets_count = job_count;
} else {
c->rets = &dummy_ret;
c->rets_count = 1;
}
pthread_cond_broadcast(&c->current_job_cond);
avcodec_thread_park_workers(c, avctx->thread_count);
return 0;
}
int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
{
int i;
ThreadContext *c;
c = av_mallocz(sizeof(ThreadContext));
if (!c)
return -1;
c->workers = av_mallocz(sizeof(pthread_t)*thread_count);
if (!c->workers) {
av_free(c);
return -1;
}
avctx->thread_opaque = c;
avctx->thread_count = thread_count;
c->current_job = 0;
c->job_count = 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<thread_count; i++) {
if(pthread_create(&c->workers[i], NULL, worker, avctx)) {
avctx->thread_count = i;
pthread_mutex_unlock(&c->current_job_lock);
avcodec_thread_free(avctx);
return -1;
}
}
avcodec_thread_park_workers(c, thread_count);
avctx->execute = avcodec_thread_execute;
return 0;
}