Libav
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00001 /* 00002 * Copyright (c) 2004 François Revol <revol@free.fr> 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 #include <OS.h> 00025 00026 typedef struct ThreadContext{ 00027 AVCodecContext *avctx; 00028 thread_id thread; 00029 sem_id work_sem; 00030 sem_id done_sem; 00031 int (*func)(AVCodecContext *c, void *arg); 00032 void *arg; 00033 int ret; 00034 }ThreadContext; 00035 00036 // it's odd Be never patented that :D 00037 struct benaphore { 00038 vint32 atom; 00039 sem_id sem; 00040 }; 00041 static inline int lock_ben(struct benaphore *ben) 00042 { 00043 if (atomic_add(&ben->atom, 1) > 0) 00044 return acquire_sem(ben->sem); 00045 return B_OK; 00046 } 00047 static inline int unlock_ben(struct benaphore *ben) 00048 { 00049 if (atomic_add(&ben->atom, -1) > 1) 00050 return release_sem(ben->sem); 00051 return B_OK; 00052 } 00053 00054 static struct benaphore av_thread_lib_ben; 00055 00056 static int32 ff_thread_func(void *v){ 00057 ThreadContext *c= v; 00058 00059 for(;;){ 00060 //printf("thread_func %X enter wait\n", (int)v); fflush(stdout); 00061 acquire_sem(c->work_sem); 00062 //printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout); 00063 if(c->func) 00064 c->ret= c->func(c->avctx, c->arg); 00065 else 00066 return 0; 00067 //printf("thread_func %X signal complete\n", (int)v); fflush(stdout); 00068 release_sem(c->done_sem); 00069 } 00070 00071 return B_OK; 00072 } 00073 00078 void avcodec_thread_free(AVCodecContext *s){ 00079 ThreadContext *c= s->thread_opaque; 00080 int i; 00081 int32 ret; 00082 00083 for(i=0; i<s->thread_count; i++){ 00084 00085 c[i].func= NULL; 00086 release_sem(c[i].work_sem); 00087 wait_for_thread(c[i].thread, &ret); 00088 if(c[i].work_sem > B_OK) delete_sem(c[i].work_sem); 00089 if(c[i].done_sem > B_OK) delete_sem(c[i].done_sem); 00090 } 00091 00092 av_freep(&s->thread_opaque); 00093 } 00094 00095 static int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size){ 00096 ThreadContext *c= s->thread_opaque; 00097 int i; 00098 00099 assert(s == c->avctx); 00100 assert(count <= s->thread_count); 00101 00102 /* note, we can be certain that this is not called with the same AVCodecContext by different threads at the same time */ 00103 00104 for(i=0; i<count; i++){ 00105 c[i].arg= (char*)arg + i*size; 00106 c[i].func= func; 00107 c[i].ret= 12345; 00108 00109 release_sem(c[i].work_sem); 00110 } 00111 for(i=0; i<count; i++){ 00112 acquire_sem(c[i].done_sem); 00113 00114 c[i].func= NULL; 00115 if(ret) ret[i]= c[i].ret; 00116 } 00117 return 0; 00118 } 00119 00120 int avcodec_thread_init(AVCodecContext *s, int thread_count){ 00121 int i; 00122 ThreadContext *c; 00123 00124 s->thread_count= thread_count; 00125 00126 if (thread_count <= 1) 00127 return 0; 00128 00129 assert(!s->thread_opaque); 00130 c= av_mallocz(sizeof(ThreadContext)*thread_count); 00131 s->thread_opaque= c; 00132 00133 for(i=0; i<thread_count; i++){ 00134 //printf("init semaphors %d\n", i); fflush(stdout); 00135 c[i].avctx= s; 00136 00137 if((c[i].work_sem = create_sem(0, "ff work sem")) < B_OK) 00138 goto fail; 00139 if((c[i].done_sem = create_sem(0, "ff done sem")) < B_OK) 00140 goto fail; 00141 00142 //printf("create thread %d\n", i); fflush(stdout); 00143 c[i].thread = spawn_thread(ff_thread_func, "libavcodec thread", B_LOW_PRIORITY, &c[i] ); 00144 if( c[i].thread < B_OK ) goto fail; 00145 resume_thread(c[i].thread ); 00146 } 00147 //printf("init done\n"); fflush(stdout); 00148 00149 s->execute= avcodec_thread_execute; 00150 00151 return 0; 00152 fail: 00153 avcodec_thread_free(s); 00154 return -1; 00155 } 00156 00157 /* provide a mean to serialize calls to avcodec_*() for thread safety. */ 00158 00159 int avcodec_thread_lock_lib(void) 00160 { 00161 return lock_ben(&av_thread_lib_ben); 00162 } 00163 00164 int avcodec_thread_unlock_lib(void) 00165 { 00166 return unlock_ben(&av_thread_lib_ben); 00167 } 00168 00169 /* our versions of _init and _fini (which are called by those actually from crt.o) */ 00170 00171 void initialize_after(void) 00172 { 00173 av_thread_lib_ben.atom = 0; 00174 av_thread_lib_ben.sem = create_sem(0, "libavcodec benaphore"); 00175 } 00176 00177 void uninitialize_before(void) 00178 { 00179 delete_sem(av_thread_lib_ben.sem); 00180 } 00181 00182 00183