libavcodec/beosthread.c

   1 /*
   2  * Copyright (c) 2004 François Revol <revol@free.fr>
   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 #include <OS.h>
  25
  26 typedef struct ThreadContext{
  27     AVCodecContext *avctx;
  28     thread_id thread;
  29     sem_id work_sem;
  30     sem_id done_sem;
  31     int (*func)(AVCodecContext *c, void *arg);
  32     void *arg;
  33     int ret;
  34 }ThreadContext;
  35
  36 // it's odd Be never patented that :D
  37 struct benaphore {
  38         vint32 atom;
  39         sem_id sem;
  40 };
  41 static inline int lock_ben(struct benaphore *ben)
  42 {
  43         if (atomic_add(&ben->atom, 1) > 0)
  44                 return acquire_sem(ben->sem);
  45         return B_OK;
  46 }
  47 static inline int unlock_ben(struct benaphore *ben)
  48 {
  49         if (atomic_add(&ben->atom, -1) > 1)
  50                 return release_sem(ben->sem);
  51         return B_OK;
  52 }
  53
  54 static struct benaphore av_thread_lib_ben;
  55
  56 static int32 ff_thread_func(void *v){
  57     ThreadContext *c= v;
  58
  59     for(;;){
  60 //printf("thread_func %X enter wait\n", (int)v); fflush(stdout);
  61         acquire_sem(c->work_sem);
  62 //printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout);
  63         if(c->func)
  64             c->ret= c->func(c->avctx, c->arg);
  65         else
  66             return 0;
  67 //printf("thread_func %X signal complete\n", (int)v); fflush(stdout);
  68         release_sem(c->done_sem);
  69     }
  70
  71     return B_OK;
  72 }
  73
  74 /**
  75  * Free what has been allocated by avcodec_thread_init().
  76  * Must be called after decoding has finished, especially do not call while avcodec_thread_execute() is running.
  77  */
  78 void avcodec_thread_free(AVCodecContext *s){
  79     ThreadContext *c= s->thread_opaque;
  80     int i;
  81     int32 ret;
  82
  83     for(i=0; i<s->thread_count; i++){
  84
  85         c[i].func= NULL;
  86         release_sem(c[i].work_sem);
  87         wait_for_thread(c[i].thread, &ret);
  88         if(c[i].work_sem > B_OK) delete_sem(c[i].work_sem);
  89         if(c[i].done_sem > B_OK) delete_sem(c[i].done_sem);
  90     }
  91
  92     av_freep(&s->thread_opaque);
  93 }
  94
  95 int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size){
  96     ThreadContext *c= s->thread_opaque;
  97     int i;
  98
  99     assert(s == c->avctx);
 100     assert(count <= s->thread_count);
 101
 102     /* note, we can be certain that this is not called with the same AVCodecContext by different threads at the same time */
 103
 104     for(i=0; i<count; i++){
 105         c[i].arg= (char*)arg + i*size;
 106         c[i].func= func;
 107         c[i].ret= 12345;
 108
 109         release_sem(c[i].work_sem);
 110     }
 111     for(i=0; i<count; i++){
 112         acquire_sem(c[i].done_sem);
 113
 114         c[i].func= NULL;
 115         if(ret) ret[i]= c[i].ret;
 116     }
 117     return 0;
 118 }
 119
 120 int avcodec_thread_init(AVCodecContext *s, int thread_count){
 121     int i;
 122     ThreadContext *c;
 123
 124     s->thread_count= thread_count;
 125
 126     assert(!s->thread_opaque);
 127     c= av_mallocz(sizeof(ThreadContext)*thread_count);
 128     s->thread_opaque= c;
 129
 130     for(i=0; i<thread_count; i++){
 131 //printf("init semaphors %d\n", i); fflush(stdout);
 132         c[i].avctx= s;
 133
 134         if((c[i].work_sem = create_sem(0, "ff work sem")) < B_OK)
 135             goto fail;
 136         if((c[i].done_sem = create_sem(0, "ff done sem")) < B_OK)
 137             goto fail;
 138
 139 //printf("create thread %d\n", i); fflush(stdout);
 140         c[i].thread = spawn_thread(ff_thread_func, "libavcodec thread", B_LOW_PRIORITY, &c[i] );
 141         if( c[i].thread < B_OK ) goto fail;
 142         resume_thread(c[i].thread );
 143     }
 144 //printf("init done\n"); fflush(stdout);
 145
 146     s->execute= avcodec_thread_execute;
 147
 148     return 0;
 149 fail:
 150     avcodec_thread_free(s);
 151     return -1;
 152 }
 153
 154 /* provide a mean to serialize calls to avcodec_*() for thread safety. */
 155
 156 int avcodec_thread_lock_lib(void)
 157 {
 158         return lock_ben(&av_thread_lib_ben);
 159 }
 160
 161 int avcodec_thread_unlock_lib(void)
 162 {
 163         return unlock_ben(&av_thread_lib_ben);
 164 }
 165
 166 /* our versions of _init and _fini (which are called by those actually from crt.o) */
 167
 168 void initialize_after(void)
 169 {
 170         av_thread_lib_ben.atom = 0;
 171         av_thread_lib_ben.sem = create_sem(0, "libavcodec benaphore");
 172 }
 173
 174 void uninitialize_before(void)
 175 {
 176         delete_sem(av_thread_lib_ben.sem);
 177 }
 178
 179
 180