git.sesse.net Git - vlc/blob - src/misc/picture_pool.c

   1 /*****************************************************************************
   2  * picture_pool.c : picture pool functions
   3  *****************************************************************************
   4  * Copyright (C) 2009 VLC authors and VideoLAN
   5  * Copyright (C) 2009 Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   6  * $Id$
   7  *
   8  * Authors: Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32 #include <assert.h>
  33
  34 #include <vlc_common.h>
  35 #include <vlc_picture_pool.h>
  36
  37 /*****************************************************************************
  38  *
  39  *****************************************************************************/
  40 struct picture_gc_sys_t {
  41     picture_pool_t *pool;
  42     picture_t *picture;
  43     bool in_use;
  44     uint64_t tick;
  45 };
  46
  47 struct picture_pool_t {
  48     uint64_t       tick;
  49     /* */
  50     unsigned       picture_count;
  51     picture_t      **picture;
  52
  53     int       (*pic_lock)(picture_t *);
  54     void      (*pic_unlock)(picture_t *);
  55     unsigned    refs;
  56     vlc_mutex_t lock;
  57 };
  58
  59 void picture_pool_Release(picture_pool_t *pool)
  60 {
  61     bool destroy;
  62
  63     vlc_mutex_lock(&pool->lock);
  64     assert(pool->refs > 0);
  65     destroy = --pool->refs == 0;
  66     vlc_mutex_unlock(&pool->lock);
  67
  68     if (likely(!destroy))
  69         return;
  70
  71     for (unsigned i = 0; i < pool->picture_count; i++) {
  72         picture_t *picture = pool->picture[i];
  73         picture_gc_sys_t *sys = picture->gc.p_sys;
  74
  75         picture_Release(sys->picture);
  76         free(sys);
  77         free(picture);
  78     }
  79
  80     vlc_mutex_destroy(&pool->lock);
  81     free(pool->picture);
  82     free(pool);
  83 }
  84
  85 static void picture_pool_ReleasePicture(picture_t *picture)
  86 {
  87     picture_gc_sys_t *sys = picture->gc.p_sys;
  88     picture_pool_t *pool = sys->pool;
  89
  90     if (pool->pic_unlock != NULL)
  91         pool->pic_unlock(picture);
  92
  93     vlc_mutex_lock(&pool->lock);
  94     assert(sys->in_use);
  95     sys->in_use = false;
  96     vlc_mutex_unlock(&pool->lock);
  97
  98     picture_pool_Release(pool);
  99 }
 100
 101 static picture_t *picture_pool_ClonePicture(picture_pool_t *pool,
 102                                             picture_t *picture)
 103 {
 104     picture_gc_sys_t *sys = malloc(sizeof(*sys));
 105     if (unlikely(sys == NULL))
 106         return NULL;
 107
 108     sys->pool = pool;
 109     sys->picture = picture;
 110     sys->in_use = false;
 111     sys->tick = 0;
 112
 113     picture_resource_t res = {
 114         .p_sys = picture->p_sys,
 115         .pf_destroy = picture_pool_ReleasePicture,
 116     };
 117
 118     for (int i = 0; i < picture->i_planes; i++) {
 119         res.p[i].p_pixels = picture->p[i].p_pixels;
 120         res.p[i].i_lines = picture->p[i].i_lines;
 121         res.p[i].i_pitch = picture->p[i].i_pitch;
 122     }
 123
 124     picture_t *clone = picture_NewFromResource(&picture->format, &res);
 125     if (likely(clone != NULL))
 126         clone->gc.p_sys = sys;
 127     else
 128         free(sys);
 129
 130     return clone;
 131 }
 132
 133 static picture_pool_t *Create(int picture_count)
 134 {
 135     picture_pool_t *pool = calloc(1, sizeof(*pool));
 136     if (!pool)
 137         return NULL;
 138
 139     pool->tick = 1;
 140     pool->picture_count = picture_count;
 141     pool->picture = calloc(pool->picture_count, sizeof(*pool->picture));
 142     if (!pool->picture) {
 143         free(pool->picture);
 144         free(pool);
 145         return NULL;
 146     }
 147     pool->refs = 1;
 148     vlc_mutex_init(&pool->lock);
 149     return pool;
 150 }
 151
 152 picture_pool_t *picture_pool_NewExtended(const picture_pool_configuration_t *cfg)
 153 {
 154     picture_pool_t *pool = Create(cfg->picture_count);
 155     if (!pool)
 156         return NULL;
 157
 158     pool->pic_lock   = cfg->lock;
 159     pool->pic_unlock = cfg->unlock;
 160
 161     for (unsigned i = 0; i < cfg->picture_count; i++) {
 162         picture_t *picture = picture_pool_ClonePicture(pool, cfg->picture[i]);
 163         if (unlikely(picture == NULL))
 164             abort();
 165
 166         atomic_init(&picture->gc.refcount, 0);
 167
 168         pool->picture[i] = picture;
 169     }
 170     return pool;
 171
 172 }
 173
 174 picture_pool_t *picture_pool_New(unsigned count, picture_t *const *tab)
 175 {
 176     picture_pool_configuration_t cfg;
 177
 178     memset(&cfg, 0, sizeof(cfg));
 179     cfg.picture_count = count;
 180     cfg.picture       = tab;
 181
 182     return picture_pool_NewExtended(&cfg);
 183 }
 184
 185 picture_pool_t *picture_pool_NewFromFormat(const video_format_t *fmt,
 186                                            unsigned count)
 187 {
 188     picture_t *picture[count ? count : 1];
 189     unsigned i;
 190
 191     for (i = 0; i < count; i++) {
 192         picture[i] = picture_NewFromFormat(fmt);
 193         if (picture[i] == NULL)
 194             goto error;
 195     }
 196
 197     picture_pool_t *pool = picture_pool_New(count, picture);
 198     if (!pool)
 199         goto error;
 200
 201     return pool;
 202
 203 error:
 204     while (i > 0)
 205         picture_Release(picture[--i]);
 206     return NULL;
 207 }
 208
 209 picture_pool_t *picture_pool_Reserve(picture_pool_t *master, unsigned count)
 210 {
 211     assert(master->pic_unlock == NULL);
 212
 213     picture_t *picture[count ? count : 1];
 214     unsigned i;
 215
 216     for (i = 0; i < count; i++) {
 217         picture[i] = picture_pool_Get(master);
 218         if (picture[i] == NULL)
 219             goto error;
 220     }
 221
 222     picture_pool_t *pool = picture_pool_New(count, picture);
 223     if (!pool)
 224         goto error;
 225
 226     return pool;
 227
 228 error:
 229     while (i > 0)
 230         picture_Release(picture[--i]);
 231     return NULL;
 232 }
 233
 234 picture_t *picture_pool_Get(picture_pool_t *pool)
 235 {
 236     vlc_mutex_lock(&pool->lock);
 237     assert(pool->refs > 0);
 238
 239     for (unsigned i = 0; i < pool->picture_count; i++) {
 240         picture_t *picture = pool->picture[i];
 241         picture_gc_sys_t *sys = picture->gc.p_sys;
 242         uint64_t tick;
 243
 244         if (sys->in_use)
 245             continue;
 246
 247         pool->refs++;
 248         tick = ++pool->tick;
 249         sys->in_use = true;
 250         vlc_mutex_unlock(&pool->lock);
 251
 252         if (pool->pic_lock != NULL && pool->pic_lock(picture) != 0) {
 253             vlc_mutex_lock(&pool->lock);
 254             sys->in_use = false;
 255             pool->refs--;
 256             continue;
 257         }
 258
 259         sys->tick = tick;
 260
 261         assert(atomic_load(&picture->gc.refcount) == 0);
 262         atomic_init(&picture->gc.refcount, 1);
 263         picture->p_next = NULL;
 264         return picture;
 265     }
 266
 267     vlc_mutex_unlock(&pool->lock);
 268     return NULL;
 269 }
 270
 271 unsigned picture_pool_Reset(picture_pool_t *pool)
 272 {
 273     unsigned ret = 0;
 274 retry:
 275     vlc_mutex_lock(&pool->lock);
 276     assert(pool->refs > 0);
 277
 278     for (unsigned i = 0; i < pool->picture_count; i++) {
 279         picture_t *picture = pool->picture[i];
 280         picture_gc_sys_t *sys = picture->gc.p_sys;
 281
 282         if (sys->in_use) {
 283             vlc_mutex_unlock(&pool->lock);
 284             picture_Release(picture);
 285             ret++;
 286             goto retry;
 287         }
 288     }
 289     vlc_mutex_unlock(&pool->lock);
 290
 291     return ret;
 292 }
 293
 294 void picture_pool_NonEmpty(picture_pool_t *pool)
 295 {
 296     picture_t *oldest = NULL;
 297     uint64_t tick = 0;
 298
 299     vlc_mutex_lock(&pool->lock);
 300     assert(pool->refs > 0);
 301
 302     for (unsigned i = 0; i < pool->picture_count; i++) {
 303         picture_t *picture = pool->picture[i];
 304         picture_gc_sys_t *sys = picture->gc.p_sys;
 305
 306         if (!sys->in_use) {
 307             vlc_mutex_unlock(&pool->lock);
 308             return; /* Nothing to do */
 309         }
 310
 311         if (picture->gc.p_sys->tick < tick) {
 312             oldest = picture;
 313             tick = picture->gc.p_sys->tick;
 314         }
 315     }
 316
 317     if (oldest != NULL) {
 318         while (oldest->gc.p_sys->in_use) {
 319             vlc_mutex_unlock(&pool->lock);
 320             picture_Release(oldest);
 321             vlc_mutex_lock(&pool->lock);
 322         }
 323     }
 324
 325     vlc_mutex_unlock(&pool->lock);
 326 }
 327
 328 unsigned picture_pool_GetSize(const picture_pool_t *pool)
 329 {
 330     return pool->picture_count;
 331 }
 332
 333 bool picture_pool_NeedsLocking(const picture_pool_t *pool)
 334 {
 335     return pool->pic_lock != NULL || pool->pic_unlock != NULL;
 336 }