libmpeg2/alloc.c

   1 /*
   2  * alloc.c
   3  * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
   4  * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
   5  *
   6  * This file is part of mpeg2dec, a free MPEG-2 video stream decoder.
   7  * See http://libmpeg2.sourceforge.net/ for updates.
   8  *
   9  * mpeg2dec is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * mpeg2dec is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include <stdlib.h>
  25 #include <inttypes.h>
  26
  27 #include "mpeg2.h"
  28
  29 static void * (* malloc_hook) (unsigned size, mpeg2_alloc_t reason) = NULL;
  30 static int (* free_hook) (void * buf) = NULL;
  31
  32 void * mpeg2_malloc (unsigned size, mpeg2_alloc_t reason)
  33 {
  34     char * buf;
  35
  36     if (malloc_hook) {
  37         buf = (char *) malloc_hook (size, reason);
  38         if (buf)
  39             return buf;
  40     }
  41
  42     if (size) {
  43         buf = (char *) malloc (size + 63 + sizeof (void **));
  44         if (buf) {
  45             char * align_buf;
  46
  47             align_buf = buf + 63 + sizeof (void **);
  48             align_buf -= (long)align_buf & 63;
  49             *(((void **)align_buf) - 1) = buf;
  50             return align_buf;
  51         }
  52     }
  53     return NULL;
  54 }
  55
  56 void mpeg2_free (void * buf)
  57 {
  58     if (free_hook && free_hook (buf))
  59         return;
  60
  61     if (buf)
  62         free (*(((void **)buf) - 1));
  63 }
  64
  65 void mpeg2_malloc_hooks (void * malloc (unsigned, mpeg2_alloc_t),
  66                          int free (void *))
  67 {
  68     malloc_hook = malloc;
  69     free_hook = free;
  70 }