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/*
* Copyright (c) 2004 François Revol <revol@free.fr>
*
* 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
*/
//#define DEBUG
#include "avcodec.h"
#include <OS.h>
typedef struct ThreadContext{
AVCodecContext *avctx;
thread_id thread;
sem_id work_sem;
sem_id done_sem;
int (*func)(AVCodecContext *c, void *arg);
void *arg;
int ret;
}ThreadContext;
// it's odd Be never patented that :D
struct benaphore {
vint32 atom;
sem_id sem;
};
static inline int lock_ben(struct benaphore *ben)
{
if (atomic_add(&ben->atom, 1) > 0)
return acquire_sem(ben->sem);
return B_OK;
}
static inline int unlock_ben(struct benaphore *ben)
{
if (atomic_add(&ben->atom, -1) > 1)
return release_sem(ben->sem);
return B_OK;
}
static struct benaphore av_thread_lib_ben;
static int32 ff_thread_func(void *v){
ThreadContext *c= v;
for(;;){
//printf("thread_func %X enter wait\n", (int)v); fflush(stdout);
acquire_sem(c->work_sem);
//printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout);
if(c->func)
c->ret= c->func(c->avctx, c->arg);
else
return 0;
//printf("thread_func %X signal complete\n", (int)v); fflush(stdout);
release_sem(c->done_sem);
}
return B_OK;
}
/**
* Free what has been allocated by avcodec_thread_init().
* Must be called after decoding has finished, especially do not call while avcodec_thread_execute() is running.
*/
void avcodec_thread_free(AVCodecContext *s){
ThreadContext *c= s->thread_opaque;
int i;
int32 ret;
for(i=0; i<s->thread_count; i++){
c[i].func= NULL;
release_sem(c[i].work_sem);
wait_for_thread(c[i].thread, &ret);
if(c[i].work_sem > B_OK) delete_sem(c[i].work_sem);
if(c[i].done_sem > B_OK) delete_sem(c[i].done_sem);
}
av_freep(&s->thread_opaque);
}
static int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size){
ThreadContext *c= s->thread_opaque;
int i;
assert(s == c->avctx);
assert(count <= s->thread_count);
/* note, we can be certain that this is not called with the same AVCodecContext by different threads at the same time */
for(i=0; i<count; i++){
c[i].arg= (char*)arg + i*size;
c[i].func= func;
c[i].ret= 12345;
release_sem(c[i].work_sem);
}
for(i=0; i<count; i++){
acquire_sem(c[i].done_sem);
c[i].func= NULL;
if(ret) ret[i]= c[i].ret;
}
return 0;
}
int avcodec_thread_init(AVCodecContext *s, int thread_count){
int i;
ThreadContext *c;
s->thread_count= thread_count;
if (thread_count <= 1)
return 0;
assert(!s->thread_opaque);
c= av_mallocz(sizeof(ThreadContext)*thread_count);
s->thread_opaque= c;
for(i=0; i<thread_count; i++){
//printf("init semaphors %d\n", i); fflush(stdout);
c[i].avctx= s;
if((c[i].work_sem = create_sem(0, "ff work sem")) < B_OK)
goto fail;
if((c[i].done_sem = create_sem(0, "ff done sem")) < B_OK)
goto fail;
//printf("create thread %d\n", i); fflush(stdout);
c[i].thread = spawn_thread(ff_thread_func, "libavcodec thread", B_LOW_PRIORITY, &c[i] );
if( c[i].thread < B_OK ) goto fail;
resume_thread(c[i].thread );
}
//printf("init done\n"); fflush(stdout);
s->execute= avcodec_thread_execute;
return 0;
fail:
avcodec_thread_free(s);
return -1;
}
/* provide a mean to serialize calls to avcodec_*() for thread safety. */
int avcodec_thread_lock_lib(void)
{
return lock_ben(&av_thread_lib_ben);
}
int avcodec_thread_unlock_lib(void)
{
return unlock_ben(&av_thread_lib_ben);
}
/* our versions of _init and _fini (which are called by those actually from crt.o) */
void initialize_after(void)
{
av_thread_lib_ben.atom = 0;
av_thread_lib_ben.sem = create_sem(0, "libavcodec benaphore");
}
void uninitialize_before(void)
{
delete_sem(av_thread_lib_ben.sem);
}
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