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libavcodec/w32thread.c

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00001 /*
00002  * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
00003  *
00004  * This file is part of FFmpeg.
00005  *
00006  * FFmpeg is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * FFmpeg is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with FFmpeg; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 //#define DEBUG
00021 
00022 #include "avcodec.h"
00023 
00024 #define WIN32_LEAN_AND_MEAN
00025 #include <windows.h>
00026 #include <process.h>
00027 
00028 typedef struct ThreadContext{
00029     AVCodecContext *avctx;
00030     HANDLE thread;
00031     HANDLE work_sem;
00032     HANDLE job_sem;
00033     HANDLE done_sem;
00034     int (*func)(AVCodecContext *c, void *arg);
00035     int (*func2)(AVCodecContext *c, void *arg, int, int);
00036     void *arg;
00037     int argsize;
00038     int *jobnr;
00039     int *ret;
00040     int threadnr;
00041 }ThreadContext;
00042 
00043 
00044 static unsigned WINAPI attribute_align_arg thread_func(void *v){
00045     ThreadContext *c= v;
00046 
00047     for(;;){
00048         int ret, jobnr;
00049 //printf("thread_func %X enter wait\n", (int)v); fflush(stdout);
00050         WaitForSingleObject(c->work_sem, INFINITE);
00051         // avoid trying to access jobnr if we should quit
00052         if (!c->func && !c->func2)
00053             break;
00054         WaitForSingleObject(c->job_sem, INFINITE);
00055         jobnr = (*c->jobnr)++;
00056         ReleaseSemaphore(c->job_sem, 1, 0);
00057 //printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout);
00058         if(c->func)
00059             ret= c->func(c->avctx, (uint8_t *)c->arg + jobnr*c->argsize);
00060         else
00061             ret= c->func2(c->avctx, c->arg, jobnr, c->threadnr);
00062         if (c->ret)
00063             c->ret[jobnr] = ret;
00064 //printf("thread_func %X signal complete\n", (int)v); fflush(stdout);
00065         ReleaseSemaphore(c->done_sem, 1, 0);
00066     }
00067 
00068     return 0;
00069 }
00070 
00075 void avcodec_thread_free(AVCodecContext *s){
00076     ThreadContext *c= s->thread_opaque;
00077     int i;
00078 
00079     for(i=0; i<s->thread_count; i++){
00080 
00081         c[i].func= NULL;
00082         c[i].func2= NULL;
00083     }
00084     ReleaseSemaphore(c[0].work_sem, s->thread_count, 0);
00085     for(i=0; i<s->thread_count; i++){
00086         WaitForSingleObject(c[i].thread, INFINITE);
00087         if(c[i].thread)   CloseHandle(c[i].thread);
00088     }
00089     if(c[0].work_sem) CloseHandle(c[0].work_sem);
00090     if(c[0].job_sem)  CloseHandle(c[0].job_sem);
00091     if(c[0].done_sem) CloseHandle(c[0].done_sem);
00092 
00093     av_freep(&s->thread_opaque);
00094 }
00095 
00096 static int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size){
00097     ThreadContext *c= s->thread_opaque;
00098     int i;
00099     int jobnr = 0;
00100 
00101     assert(s == c->avctx);
00102 
00103     /* note, we can be certain that this is not called with the same AVCodecContext by different threads at the same time */
00104 
00105     for(i=0; i<s->thread_count; i++){
00106         c[i].arg= arg;
00107         c[i].argsize= size;
00108         c[i].func= func;
00109         c[i].ret= ret;
00110         c[i].jobnr = &jobnr;
00111     }
00112     ReleaseSemaphore(c[0].work_sem, count, 0);
00113     for(i=0; i<count; i++)
00114         WaitForSingleObject(c[0].done_sem, INFINITE);
00115 
00116     return 0;
00117 }
00118 
00119 static int avcodec_thread_execute2(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count){
00120     ThreadContext *c= s->thread_opaque;
00121     int i;
00122     for(i=0; i<s->thread_count; i++)
00123         c[i].func2 = func;
00124     avcodec_thread_execute(s, NULL, arg, ret, count, 0);
00125 }
00126 
00127 int avcodec_thread_init(AVCodecContext *s, int thread_count){
00128     int i;
00129     ThreadContext *c;
00130     uint32_t threadid;
00131 
00132     s->thread_count= thread_count;
00133 
00134     if (thread_count <= 1)
00135         return 0;
00136 
00137     assert(!s->thread_opaque);
00138     c= av_mallocz(sizeof(ThreadContext)*thread_count);
00139     s->thread_opaque= c;
00140     if(!(c[0].work_sem = CreateSemaphore(NULL, 0, INT_MAX, NULL)))
00141         goto fail;
00142     if(!(c[0].job_sem  = CreateSemaphore(NULL, 1, 1, NULL)))
00143         goto fail;
00144     if(!(c[0].done_sem = CreateSemaphore(NULL, 0, INT_MAX, NULL)))
00145         goto fail;
00146 
00147     for(i=0; i<thread_count; i++){
00148 //printf("init semaphors %d\n", i); fflush(stdout);
00149         c[i].avctx= s;
00150         c[i].work_sem = c[0].work_sem;
00151         c[i].job_sem  = c[0].job_sem;
00152         c[i].done_sem = c[0].done_sem;
00153         c[i].threadnr = i;
00154 
00155 //printf("create thread %d\n", i); fflush(stdout);
00156         c[i].thread = (HANDLE)_beginthreadex(NULL, 0, thread_func, &c[i], 0, &threadid );
00157         if( !c[i].thread ) goto fail;
00158     }
00159 //printf("init done\n"); fflush(stdout);
00160 
00161     s->execute= avcodec_thread_execute;
00162     s->execute2= avcodec_thread_execute2;
00163 
00164     return 0;
00165 fail:
00166     avcodec_thread_free(s);
00167     return -1;
00168 }

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