libavcodec/w32thread.c

   1 /*
   2  * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20 //#define DEBUG
  21
  22 #include "avcodec.h"
  23
  24 #define WIN32_LEAN_AND_MEAN
  25 #include <windows.h>
  26 #include <process.h>
  27
  28 typedef struct ThreadContext{
  29     AVCodecContext *avctx;
  30     HANDLE thread;
  31     HANDLE work_sem;
  32     HANDLE done_sem;
  33     int (*func)(AVCodecContext *c, void *arg);
  34     void *arg;
  35     int ret;
  36 }ThreadContext;
  37
  38
  39 static unsigned WINAPI attribute_align_arg thread_func(void *v){
  40     ThreadContext *c= v;
  41
  42     for(;;){
  43 //printf("thread_func %X enter wait\n", (int)v); fflush(stdout);
  44         WaitForSingleObject(c->work_sem, INFINITE);
  45 //printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout);
  46         if(c->func)
  47             c->ret= c->func(c->avctx, c->arg);
  48         else
  49             return 0;
  50 //printf("thread_func %X signal complete\n", (int)v); fflush(stdout);
  51         ReleaseSemaphore(c->done_sem, 1, 0);
  52     }
  53
  54     return 0;
  55 }
  56
  57 /**
  58  * Free what has been allocated by avcodec_thread_init().
  59  * Must be called after decoding has finished, especially do not call while avcodec_thread_execute() is running.
  60  */
  61 void avcodec_thread_free(AVCodecContext *s){
  62     ThreadContext *c= s->thread_opaque;
  63     int i;
  64
  65     for(i=0; i<s->thread_count; i++){
  66
  67         c[i].func= NULL;
  68         ReleaseSemaphore(c[i].work_sem, 1, 0);
  69         WaitForSingleObject(c[i].thread, INFINITE);
  70         if(c[i].work_sem) CloseHandle(c[i].work_sem);
  71         if(c[i].done_sem) CloseHandle(c[i].done_sem);
  72     }
  73
  74     av_freep(&s->thread_opaque);
  75 }
  76
  77 int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size){
  78     ThreadContext *c= s->thread_opaque;
  79     int i;
  80
  81     assert(s == c->avctx);
  82     assert(count <= s->thread_count);
  83
  84     /* note, we can be certain that this is not called with the same AVCodecContext by different threads at the same time */
  85
  86     for(i=0; i<count; i++){
  87         c[i].arg= (char*)arg + i*size;
  88         c[i].func= func;
  89         c[i].ret= 12345;
  90
  91         ReleaseSemaphore(c[i].work_sem, 1, 0);
  92     }
  93     for(i=0; i<count; i++){
  94         WaitForSingleObject(c[i].done_sem, INFINITE);
  95
  96         c[i].func= NULL;
  97         if(ret) ret[i]= c[i].ret;
  98     }
  99     return 0;
 100 }
 101
 102 int avcodec_thread_init(AVCodecContext *s, int thread_count){
 103     int i;
 104     ThreadContext *c;
 105     uint32_t threadid;
 106
 107     s->thread_count= thread_count;
 108
 109     assert(!s->thread_opaque);
 110     c= av_mallocz(sizeof(ThreadContext)*thread_count);
 111     s->thread_opaque= c;
 112
 113     for(i=0; i<thread_count; i++){
 114 //printf("init semaphors %d\n", i); fflush(stdout);
 115         c[i].avctx= s;
 116
 117         if(!(c[i].work_sem = CreateSemaphore(NULL, 0, s->thread_count, NULL)))
 118             goto fail;
 119         if(!(c[i].done_sem = CreateSemaphore(NULL, 0, s->thread_count, NULL)))
 120             goto fail;
 121
 122 //printf("create thread %d\n", i); fflush(stdout);
 123         c[i].thread = (HANDLE)_beginthreadex(NULL, 0, thread_func, &c[i], 0, &threadid );
 124         if( !c[i].thread ) goto fail;
 125     }
 126 //printf("init done\n"); fflush(stdout);
 127
 128     s->execute= avcodec_thread_execute;
 129
 130     return 0;
 131 fail:
 132     avcodec_thread_free(s);
 133     return -1;
 134 }