libavutil/mem.h

   1 /*
   2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   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 /**
  22  * @file libavutil/mem.h
  23  * memory handling functions
  24  */
  25
  26 #ifndef AVUTIL_MEM_H
  27 #define AVUTIL_MEM_H
  28
  29 #include "common.h"
  30
  31 #if AV_GCC_VERSION_AT_LEAST(3,1)
  32     #define av_malloc_attrib __attribute__((__malloc__))
  33 #else
  34     #define av_malloc_attrib
  35 #endif
  36
  37 #if (!defined(__ICC) || __ICC > 1100) && AV_GCC_VERSION_AT_LEAST(4,3)
  38     #define av_alloc_size(n) __attribute__((alloc_size(n)))
  39 #else
  40     #define av_alloc_size(n)
  41 #endif
  42
  43 /**
  44  * Allocates a block of \p size bytes with alignment suitable for all
  45  * memory accesses (including vectors if available on the CPU).
  46  * @param size Size in bytes for the memory block to be allocated.
  47  * @return Pointer to the allocated block, NULL if the block cannot
  48  * be allocated.
  49  * @see av_mallocz()
  50  */
  51 void *av_malloc(unsigned int size) av_malloc_attrib av_alloc_size(1);
  52
  53 /**
  54  * Allocates or reallocates a block of memory.
  55  * If \p ptr is NULL and \p size > 0, allocates a new block. If \p
  56  * size is zero, frees the memory block pointed to by \p ptr.
  57  * @param size Size in bytes for the memory block to be allocated or
  58  * reallocated.
  59  * @param ptr Pointer to a memory block already allocated with
  60  * av_malloc(z)() or av_realloc() or NULL.
  61  * @return Pointer to a newly reallocated block or NULL if the block
  62  * cannot be reallocated or the function is used to free the memory block.
  63  * @see av_fast_realloc()
  64  */
  65 void *av_realloc(void *ptr, unsigned int size) av_alloc_size(2);
  66
  67 /**
  68  * Frees a memory block which has been allocated with av_malloc(z)() or
  69  * av_realloc().
  70  * @param ptr Pointer to the memory block which should be freed.
  71  * @note ptr = NULL is explicitly allowed.
  72  * @note It is recommended that you use av_freep() instead.
  73  * @see av_freep()
  74  */
  75 void av_free(void *ptr);
  76
  77 /**
  78  * Allocates a block of \p size bytes with alignment suitable for all
  79  * memory accesses (including vectors if available on the CPU) and
  80  * zeroes all the bytes of the block.
  81  * @param size Size in bytes for the memory block to be allocated.
  82  * @return Pointer to the allocated block, NULL if it cannot be allocated.
  83  * @see av_malloc()
  84  */
  85 void *av_mallocz(unsigned int size) av_malloc_attrib av_alloc_size(1);
  86
  87 /**
  88  * Duplicates the string \p s.
  89  * @param s string to be duplicated
  90  * @return Pointer to a newly allocated string containing a
  91  * copy of \p s or NULL if the string cannot be allocated.
  92  */
  93 char *av_strdup(const char *s) av_malloc_attrib;
  94
  95 /**
  96  * Frees a memory block which has been allocated with av_malloc(z)() or
  97  * av_realloc() and set the pointer pointing to it to NULL.
  98  * @param ptr Pointer to the pointer to the memory block which should
  99  * be freed.
 100  * @see av_free()
 101  */
 102 void av_freep(void *ptr);
 103
 104 #endif /* AVUTIL_MEM_H */