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  */
  21 //#define DEBUG
  22
  23 #include "avcodec.h"
  24
  25 #include <OS.h>
  26
  27 typedef struct ThreadContext{
  28     AVCodecContext *avctx;
  29     thread_id thread;
  30     sem_id work_sem;
  31     sem_id done_sem;
  32     int (*func)(AVCodecContext *c, void *arg);
  33     void *arg;
  34     int ret;
  35 }ThreadContext;
  36
  37 // it's odd Be never patented that :D
  38 struct benaphore {
  39         vint32 atom;
  40         sem_id sem;
  41 };
  42 static inline int lock_ben(struct benaphore *ben)
  43 {
  44         if (atomic_add(&ben->atom, 1) > 0)
  45                 return acquire_sem(ben->sem);
  46         return B_OK;
  47 }
  48 static inline int unlock_ben(struct benaphore *ben)
  49 {
  50         if (atomic_add(&ben->atom, -1) > 1)
  51                 return release_sem(ben->sem);
  52         return B_OK;
  53 }
  54
  55 static struct benaphore av_thread_lib_ben;
  56
  57 static int32 ff_thread_func(void *v){
  58     ThreadContext *c= v;
  59
  60     for(;;){
  61 //printf("thread_func %X enter wait\n", (int)v); fflush(stdout);
  62         acquire_sem(c->work_sem);
  63 //printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout);
  64         if(c->func)
  65             c->ret= c->func(c->avctx, c->arg);
  66         else
  67             return 0;
  68 //printf("thread_func %X signal complete\n", (int)v); fflush(stdout);
  69         release_sem(c->done_sem);
  70     }
  71
  72     return B_OK;
  73 }
  74
  75 /**
  76  * free what has been allocated by avcodec_thread_init().
  77  * must be called after decoding has finished, especially dont call while avcodec_thread_execute() is running
  78  */
  79 void avcodec_thread_free(AVCodecContext *s){
  80     ThreadContext *c= s->thread_opaque;
  81     int i;
  82     int32 ret;
  83
  84     for(i=0; i<s->thread_count; i++){
  85
  86         c[i].func= NULL;
  87         release_sem(c[i].work_sem);
  88         wait_for_thread(c[i].thread, &ret);
  89         if(c[i].work_sem > B_OK) delete_sem(c[i].work_sem);
  90         if(c[i].done_sem > B_OK) delete_sem(c[i].done_sem);
  91     }
  92
  93     av_freep(&s->thread_opaque);
  94 }
  95
  96 int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void **arg, int *ret, int count){
  97     ThreadContext *c= s->thread_opaque;
  98     int i;
  99
 100     assert(s == c->avctx);
 101     assert(count <= s->thread_count);
 102
 103     /* note, we can be certain that this is not called with the same AVCodecContext by different threads at the same time */
 104
 105     for(i=0; i<count; i++){
 106         c[i].arg= arg[i];
 107         c[i].func= func;
 108         c[i].ret= 12345;
 109
 110         release_sem(c[i].work_sem);
 111     }
 112     for(i=0; i<count; i++){
 113         acquire_sem(c[i].done_sem);
 114
 115         c[i].func= NULL;
 116         if(ret) ret[i]= c[i].ret;
 117     }
 118     return 0;
 119 }
 120
 121 int avcodec_thread_init(AVCodecContext *s, int thread_count){
 122     int i;
 123     ThreadContext *c;
 124
 125     s->thread_count= thread_count;
 126
 127     assert(!s->thread_opaque);
 128     c= av_mallocz(sizeof(ThreadContext)*thread_count);
 129     s->thread_opaque= c;
 130
 131     for(i=0; i<thread_count; i++){
 132 //printf("init semaphors %d\n", i); fflush(stdout);
 133         c[i].avctx= s;
 134
 135         if((c[i].work_sem = create_sem(0, "ff work sem")) < B_OK)
 136             goto fail;
 137         if((c[i].done_sem = create_sem(0, "ff done sem")) < B_OK)
 138             goto fail;
 139
 140 //printf("create thread %d\n", i); fflush(stdout);
 141         c[i].thread = spawn_thread(ff_thread_func, "libavcodec thread", B_LOW_PRIORITY, &c[i] );
 142         if( c[i].thread < B_OK ) goto fail;
 143         resume_thread(c[i].thread );
 144     }
 145 //printf("init done\n"); fflush(stdout);
 146
 147     s->execute= avcodec_thread_execute;
 148
 149     return 0;
 150 fail:
 151     avcodec_thread_free(s);
 152     return -1;
 153 }
 154
 155 /* provide a mean to serialize calls to avcodec_*() for thread safety. */
 156
 157 int avcodec_thread_lock_lib(void)
 158 {
 159         return lock_ben(&av_thread_lib_ben);
 160 }
 161
 162 int avcodec_thread_unlock_lib(void)
 163 {
 164         return unlock_ben(&av_thread_lib_ben);
 165 }
 166
 167 /* our versions of _init and _fini (which are called by those actually from crt.o) */
 168
 169 void initialize_after(void)
 170 {
 171         av_thread_lib_ben.atom = 0;
 172         av_thread_lib_ben.sem = create_sem(0, "libavcodec benaphore");
 173 }
 174
 175 void uninitialize_before(void)
 176 {
 177         delete_sem(av_thread_lib_ben.sem);
 178 }
 179
 180
 181