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   1 /*
   2  * This file is part of FFmpeg.
   3  *
   4  * FFmpeg is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * FFmpeg is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with FFmpeg; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 /**
  20  * @file
  21  * Slice multithreading support functions
  22  * @see doc/multithreading.txt
  23  */
  24
  25 #include "config.h"
  26
  27 #if HAVE_PTHREADS
  28 #include <pthread.h>
  29 #elif HAVE_W32THREADS
  30 #include "compat/w32pthreads.h"
  31 #elif HAVE_OS2THREADS
  32 #include "compat/os2threads.h"
  33 #endif
  34
  35 #include "avcodec.h"
  36 #include "internal.h"
  37 #include "pthread_internal.h"
  38 #include "thread.h"
  39
  40 #include "libavutil/avassert.h"
  41 #include "libavutil/common.h"
  42 #include "libavutil/cpu.h"
  43 #include "libavutil/mem.h"
  44
  45 typedef int (action_func)(AVCodecContext *c, void *arg);
  46 typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);
  47
  48 typedef struct SliceThreadContext {
  49     pthread_t *workers;
  50     action_func *func;
  51     action_func2 *func2;
  52     void *args;
  53     int *rets;
  54     int job_count;
  55     int job_size;
  56
  57     pthread_cond_t last_job_cond;
  58     pthread_cond_t current_job_cond;
  59     pthread_mutex_t current_job_lock;
  60     unsigned current_execute;
  61     int current_job;
  62     int done;
  63
  64     int *entries;
  65     int entries_count;
  66     int thread_count;
  67     pthread_cond_t *progress_cond;
  68     pthread_mutex_t *progress_mutex;
  69 } SliceThreadContext;
  70
  71 static void* attribute_align_arg worker(void *v)
  72 {
  73     AVCodecContext *avctx = v;
  74     SliceThreadContext *c = avctx->internal->thread_ctx;
  75     unsigned last_execute = 0;
  76     int our_job = c->job_count;
  77     int thread_count = avctx->thread_count;
  78     int self_id;
  79
  80     pthread_mutex_lock(&c->current_job_lock);
  81     self_id = c->current_job++;
  82     for (;;){
  83         int ret;
  84         while (our_job >= c->job_count) {
  85             if (c->current_job == thread_count + c->job_count)
  86                 pthread_cond_signal(&c->last_job_cond);
  87
  88             while (last_execute == c->current_execute && !c->done)
  89                 pthread_cond_wait(&c->current_job_cond, &c->current_job_lock);
  90             last_execute = c->current_execute;
  91             our_job = self_id;
  92
  93             if (c->done) {
  94                 pthread_mutex_unlock(&c->current_job_lock);
  95                 return NULL;
  96             }
  97         }
  98         pthread_mutex_unlock(&c->current_job_lock);
  99
 100         ret = c->func ? c->func(avctx, (char*)c->args + our_job*c->job_size):
 101                                 c->func2(avctx, c->args, our_job, self_id);
 102         if (c->rets)
 103             c->rets[our_job%c->job_count] = ret;
 104
 105         pthread_mutex_lock(&c->current_job_lock);
 106         our_job = c->current_job++;
 107     }
 108 }
 109
 110 void ff_slice_thread_free(AVCodecContext *avctx)
 111 {
 112     SliceThreadContext *c = avctx->internal->thread_ctx;
 113     int i;
 114
 115     pthread_mutex_lock(&c->current_job_lock);
 116     c->done = 1;
 117     pthread_cond_broadcast(&c->current_job_cond);
 118     for (i = 0; i < c->thread_count; i++)
 119         pthread_cond_broadcast(&c->progress_cond[i]);
 120     pthread_mutex_unlock(&c->current_job_lock);
 121
 122     for (i=0; i<avctx->thread_count; i++)
 123          pthread_join(c->workers[i], NULL);
 124
 125     for (i = 0; i < c->thread_count; i++) {
 126         pthread_mutex_destroy(&c->progress_mutex[i]);
 127         pthread_cond_destroy(&c->progress_cond[i]);
 128     }
 129
 130     pthread_mutex_destroy(&c->current_job_lock);
 131     pthread_cond_destroy(&c->current_job_cond);
 132     pthread_cond_destroy(&c->last_job_cond);
 133
 134     av_freep(&c->entries);
 135     av_freep(&c->progress_mutex);
 136     av_freep(&c->progress_cond);
 137
 138     av_freep(&c->workers);
 139     av_freep(&avctx->internal->thread_ctx);
 140 }
 141
 142 static av_always_inline void thread_park_workers(SliceThreadContext *c, int thread_count)
 143 {
 144     while (c->current_job != thread_count + c->job_count)
 145         pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);
 146     pthread_mutex_unlock(&c->current_job_lock);
 147 }
 148
 149 static int thread_execute(AVCodecContext *avctx, action_func* func, void *arg, int *ret, int job_count, int job_size)
 150 {
 151     SliceThreadContext *c = avctx->internal->thread_ctx;
 152
 153     if (!(avctx->active_thread_type&FF_THREAD_SLICE) || avctx->thread_count <= 1)
 154         return avcodec_default_execute(avctx, func, arg, ret, job_count, job_size);
 155
 156     if (job_count <= 0)
 157         return 0;
 158
 159     pthread_mutex_lock(&c->current_job_lock);
 160
 161     c->current_job = avctx->thread_count;
 162     c->job_count = job_count;
 163     c->job_size = job_size;
 164     c->args = arg;
 165     c->func = func;
 166     if (ret) {
 167         c->rets = ret;
 168     } else {
 169         c->rets = NULL;
 170     }
 171     c->current_execute++;
 172     pthread_cond_broadcast(&c->current_job_cond);
 173
 174     thread_park_workers(c, avctx->thread_count);
 175
 176     return 0;
 177 }
 178
 179 static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
 180 {
 181     SliceThreadContext *c = avctx->internal->thread_ctx;
 182     c->func2 = func2;
 183     return thread_execute(avctx, NULL, arg, ret, job_count, 0);
 184 }
 185
 186 int ff_slice_thread_init(AVCodecContext *avctx)
 187 {
 188     int i;
 189     SliceThreadContext *c;
 190     int thread_count = avctx->thread_count;
 191
 192 #if HAVE_W32THREADS
 193     w32thread_init();
 194 #endif
 195
 196     if (!thread_count) {
 197         int nb_cpus = av_cpu_count();
 198         if  (avctx->height)
 199             nb_cpus = FFMIN(nb_cpus, (avctx->height+15)/16);
 200         // use number of cores + 1 as thread count if there is more than one
 201         if (nb_cpus > 1)
 202             thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
 203         else
 204             thread_count = avctx->thread_count = 1;
 205     }
 206
 207     if (thread_count <= 1) {
 208         avctx->active_thread_type = 0;
 209         return 0;
 210     }
 211
 212     c = av_mallocz(sizeof(SliceThreadContext));
 213     if (!c)
 214         return -1;
 215
 216     c->workers = av_mallocz_array(thread_count, sizeof(pthread_t));
 217     if (!c->workers) {
 218         av_free(c);
 219         return -1;
 220     }
 221
 222     avctx->internal->thread_ctx = c;
 223     c->current_job = 0;
 224     c->job_count = 0;
 225     c->job_size = 0;
 226     c->done = 0;
 227     pthread_cond_init(&c->current_job_cond, NULL);
 228     pthread_cond_init(&c->last_job_cond, NULL);
 229     pthread_mutex_init(&c->current_job_lock, NULL);
 230     pthread_mutex_lock(&c->current_job_lock);
 231     for (i=0; i<thread_count; i++) {
 232         if(pthread_create(&c->workers[i], NULL, worker, avctx)) {
 233            avctx->thread_count = i;
 234            pthread_mutex_unlock(&c->current_job_lock);
 235            ff_thread_free(avctx);
 236            return -1;
 237         }
 238     }
 239
 240     thread_park_workers(c, thread_count);
 241
 242     avctx->execute = thread_execute;
 243     avctx->execute2 = thread_execute2;
 244     return 0;
 245 }
 246
 247 void ff_thread_report_progress2(AVCodecContext *avctx, int field, int thread, int n)
 248 {
 249     SliceThreadContext *p = avctx->internal->thread_ctx;
 250     int *entries = p->entries;
 251
 252     pthread_mutex_lock(&p->progress_mutex[thread]);
 253     entries[field] +=n;
 254     pthread_cond_signal(&p->progress_cond[thread]);
 255     pthread_mutex_unlock(&p->progress_mutex[thread]);
 256 }
 257
 258 void ff_thread_await_progress2(AVCodecContext *avctx, int field, int thread, int shift)
 259 {
 260     SliceThreadContext *p  = avctx->internal->thread_ctx;
 261     int *entries      = p->entries;
 262
 263     if (!entries || !field) return;
 264
 265     thread = thread ? thread - 1 : p->thread_count - 1;
 266
 267     pthread_mutex_lock(&p->progress_mutex[thread]);
 268     while ((entries[field - 1] - entries[field]) < shift){
 269         pthread_cond_wait(&p->progress_cond[thread], &p->progress_mutex[thread]);
 270     }
 271     pthread_mutex_unlock(&p->progress_mutex[thread]);
 272 }
 273
 274 int ff_alloc_entries(AVCodecContext *avctx, int count)
 275 {
 276     int i;
 277
 278     if (avctx->active_thread_type & FF_THREAD_SLICE)  {
 279         SliceThreadContext *p = avctx->internal->thread_ctx;
 280
 281         if (p->entries) {
 282             av_assert0(p->thread_count == avctx->thread_count);
 283             av_freep(&p->entries);
 284         }
 285
 286         p->thread_count  = avctx->thread_count;
 287         p->entries       = av_mallocz_array(count, sizeof(int));
 288
 289         if (!p->progress_mutex) {
 290             p->progress_mutex = av_malloc_array(p->thread_count, sizeof(pthread_mutex_t));
 291             p->progress_cond  = av_malloc_array(p->thread_count, sizeof(pthread_cond_t));
 292         }
 293
 294         if (!p->entries || !p->progress_mutex || !p->progress_cond) {
 295             av_freep(&p->entries);
 296             av_freep(&p->progress_mutex);
 297             av_freep(&p->progress_cond);
 298             return AVERROR(ENOMEM);
 299         }
 300         p->entries_count  = count;
 301
 302         for (i = 0; i < p->thread_count; i++) {
 303             pthread_mutex_init(&p->progress_mutex[i], NULL);
 304             pthread_cond_init(&p->progress_cond[i], NULL);
 305         }
 306     }
 307
 308     return 0;
 309 }
 310
 311 void ff_reset_entries(AVCodecContext *avctx)
 312 {
 313     SliceThreadContext *p = avctx->internal->thread_ctx;
 314     memset(p->entries, 0, p->entries_count * sizeof(int));
 315 }