Chiebot-Mirror
/
FFmpeg
mirror of https://github.com/FFmpeg/FFmpeg.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity

* reimplementation using mutexes and condition variables.

Browse Source 
Originally committed as revision 3138 to svn://svn.ffmpeg.org/ffmpeg/trunk
pull/126/head
Roman Shaposhnik 21 years ago
parent ffc0ef960b
commit a8eb52a8c3
1 changed files with 122 additions and 155 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 277
      libavcodec/pthread.c

277
libavcodec/pthread.c
Unescape View File

@ -1,5 +1,9 @@
/*
* Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
* 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 library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@ -16,186 +20,149 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <semaphore.h>
#include <pthread.h>
//#define DEBUG
#include "avcodec.h"
#include "common.h"
typedef struct JobContext{
sem_t available_sem;
int assigned;
int (*func)(AVCodecContext *c, void *arg);
void *arg;
int ret;
}JobContext;
typedef struct WorkerContext{
AVCodecContext *avctx;
pthread_t thread;
int start_index;
sem_t work_sem;
sem_t done_sem;
}WorkerContext;
typedef int (action_t)(AVCodecContext *c, void *arg);
typedef struct ThreadContext{
WorkerContext *worker;
JobContext *job;
typedef struct ThreadContext {
pthread_t *workers;
action_t *func;
void **args;
int *rets;
int rets_count;
int job_count;
int allocated_job_count;
}ThreadContext;
static void * thread_func(void *v){
WorkerContext *w= v;
ThreadContext *c= w->avctx->thread_opaque;
int i;
for(;;){
//av_log(w->avctx, AV_LOG_DEBUG, "thread_func %X enter wait\n", (int)v);
sem_wait(&w->work_sem);
//av_log(w->avctx, AV_LOG_DEBUG, "thread_func %X after wait\n", (int)v);
if(c->job_count == 0)
break;
for(i=0; i<c->job_count; i++){
int index= (i + w->start_index) % c->job_count;
JobContext *j= &c->job[index];
//av_log(w->avctx, AV_LOG_DEBUG, "thread_func %X first check of %d\n", (int)v, index);
if(j->assigned) continue; //unsynced check, if != 0 it is already given to another worker, it never becomes available before the next execute() call so this should be safe
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* 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);
//av_log(w->avctx, AV_LOG_DEBUG, "thread_func %X second check of %d\n", (int)v, index);
if(sem_trywait(&j->available_sem) == 0){
j->assigned=1;
j->ret= j->func(w->avctx, j->arg);
//av_log(w->avctx, AV_LOG_DEBUG, "thread_func %X done %d\n", (int)v, index);
}
}
//av_log(w->avctx, AV_LOG_DEBUG, "thread_func %X complete\n", (int)v);
sem_post(&w->done_sem);
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++;
}
return NULL;
}
/**
* free what has been allocated by avcodec_thread_init().
* must be called after decoding has finished, especially dont call while avcodec_thread_execute() is running
*/
void avcodec_thread_free(AVCodecContext *s){
ThreadContext *c= s->thread_opaque;
int i, val;
for(i=0; i<c->allocated_job_count; i++){
sem_getvalue(&c->job[i].available_sem, &val); assert(val == 0);
sem_destroy(&c->job[i].available_sem);
}
c->job_count= 0;
for(i=0; i<s->thread_count; i++){
sem_getvalue(&c->worker[i].work_sem, &val); assert(val == 0);
sem_getvalue(&c->worker[i].done_sem, &val); assert(val == 0);
sem_post(&c->worker[i].work_sem);
pthread_join(c->worker[i].thread, NULL);
sem_destroy(&c->worker[i].work_sem);
sem_destroy(&c->worker[i].done_sem);
}
av_freep(&c->job);
av_freep(&c->worker);
av_freep(&s->thread_opaque);
static 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);
}
int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void **arg, int *ret, int job_count){
ThreadContext *c= s->thread_opaque;
int i, val;
void avcodec_thread_free(AVCodecContext *avctx)
{
ThreadContext *c = avctx->thread_opaque;
int i;
assert(s == c->avctx);
if(job_count > c->allocated_job_count){
c->job= av_realloc(c->job, job_count*sizeof(JobContext));
for(i=c->allocated_job_count; i<job_count; i++){
memset(&c->job[i], 0, sizeof(JobContext));
c->allocated_job_count++;
pthread_mutex_lock(&c->current_job_lock);
c->done = 1;
pthread_cond_signal(&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(c);
}
if(sem_init(&c->job[i].available_sem, 0, 0))
return -1;
}
}
c->job_count= job_count;
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;
/* 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<job_count; i++){
sem_getvalue(&c->job[i].available_sem, &val); assert(val == 0);
c->job[i].arg= arg[i];
c->job[i].func= func;
c->job[i].ret= 12345;
c->job[i].assigned= 0;
sem_post(&c->job[i].available_sem);
}
for(i=0; i<s->thread_count && i<job_count; i++){
sem_getvalue(&c->worker[i].work_sem, &val); assert(val == 0);
sem_getvalue(&c->worker[i].done_sem, &val); assert(val == 0);
c->worker[i].start_index= (i + job_count/2)/job_count;
//av_log(s, AV_LOG_DEBUG, "start worker %d\n", i);
sem_post(&c->worker[i].work_sem);
}
for(i=0; i<s->thread_count && i<job_count; i++){
//av_log(s, AV_LOG_DEBUG, "wait for worker %d\n", i);
sem_wait(&c->worker[i].done_sem);
sem_getvalue(&c->worker[i].work_sem, &val); assert(val == 0);
sem_getvalue(&c->worker[i].done_sem, &val); assert(val == 0);
}
for(i=0; i<job_count; i++){
sem_getvalue(&c->job[i].available_sem, &val); assert(val == 0);
c->job[i].func= NULL;
if(ret) ret[i]= c->job[i].ret;
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 *s, int thread_count){
int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
{
int i;
ThreadContext *c;
WorkerContext *worker;
s->thread_count= thread_count;
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;
}
assert(!s->thread_opaque);
c= av_mallocz(sizeof(ThreadContext));
worker= av_mallocz(sizeof(WorkerContext)*thread_count);
s->thread_opaque= c;
c->worker= worker;
for(i=0; i<thread_count; i++){
//printf("init semaphors %d\n", i); fflush(stdout);
worker[i].avctx= s;
if(sem_init(&worker[i].work_sem, 0, 0))
goto fail;
if(sem_init(&worker[i].done_sem, 0, 0))
goto fail;
//printf("create thread %d\n", i); fflush(stdout);
if(pthread_create(&worker[i].thread, NULL, thread_func, &worker[i]))
goto fail;
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;
}
}
//printf("init done\n"); fflush(stdout);
s->execute= avcodec_thread_execute;
avcodec_thread_park_workers(c, thread_count);
avctx->execute = avcodec_thread_execute;
return 0;
fail:
avcodec_thread_free(s);
return -1;
}

Write Preview
Loading…
Cancel
Save