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 defined(__ICC) || defined(__SUNPRO_C)
  32     #define DECLARE_ALIGNED(n,t,v)      t v __attribute__ ((aligned (n)))
  33     #define DECLARE_ASM_CONST(n,t,v)    const t __attribute__ ((aligned (n))) v
  34 #elif defined(__GNUC__)
  35     #define DECLARE_ALIGNED(n,t,v)      t v __attribute__ ((aligned (n)))
  36     #define DECLARE_ASM_CONST(n,t,v)    static const t v attribute_used __attribute__ ((aligned (n)))
  37 #elif defined(_MSC_VER)
  38     #define DECLARE_ALIGNED(n,t,v)      __declspec(align(n)) t v
  39     #define DECLARE_ASM_CONST(n,t,v)    __declspec(align(n)) static const t v
  40 #else
  41     #define DECLARE_ALIGNED(n,t,v)      t v
  42     #define DECLARE_ASM_CONST(n,t,v)    static const t v
  43 #endif
  44
  45
  46 #if AV_GCC_VERSION_AT_LEAST(3,1)
  47     #define av_malloc_attrib __attribute__((__malloc__))
  48 #else
  49     #define av_malloc_attrib
  50 #endif
  51
  52 #if (!defined(__ICC) || __ICC > 1110) && AV_GCC_VERSION_AT_LEAST(4,3)
  53     #define av_alloc_size(n) __attribute__((alloc_size(n)))
  54 #else
  55     #define av_alloc_size(n)
  56 #endif
  57
  58 /**
  59  * Allocates a block of size bytes with alignment suitable for all
  60  * memory accesses (including vectors if available on the CPU).
  61  * @param size Size in bytes for the memory block to be allocated.
  62  * @return Pointer to the allocated block, NULL if the block cannot
  63  * be allocated.
  64  * @see av_mallocz()
  65  */
  66 void *av_malloc(unsigned int size) av_malloc_attrib av_alloc_size(1);
  67
  68 /**
  69  * Allocates or reallocates a block of memory.
  70  * If ptr is NULL and size > 0, allocates a new block. If \p
  71  * size is zero, frees the memory block pointed to by ptr.
  72  * @param size Size in bytes for the memory block to be allocated or
  73  * reallocated.
  74  * @param ptr Pointer to a memory block already allocated with
  75  * av_malloc(z)() or av_realloc() or NULL.
  76  * @return Pointer to a newly reallocated block or NULL if the block
  77  * cannot be reallocated or the function is used to free the memory block.
  78  * @see av_fast_realloc()
  79  */
  80 void *av_realloc(void *ptr, unsigned int size) av_alloc_size(2);
  81
  82 /**
  83  * Frees a memory block which has been allocated with av_malloc(z)() or
  84  * av_realloc().
  85  * @param ptr Pointer to the memory block which should be freed.
  86  * @note ptr = NULL is explicitly allowed.
  87  * @note It is recommended that you use av_freep() instead.
  88  * @see av_freep()
  89  */
  90 void av_free(void *ptr);
  91
  92 /**
  93  * Allocates a block of size bytes with alignment suitable for all
  94  * memory accesses (including vectors if available on the CPU) and
  95  * zeroes all the bytes of the block.
  96  * @param size Size in bytes for the memory block to be allocated.
  97  * @return Pointer to the allocated block, NULL if it cannot be allocated.
  98  * @see av_malloc()
  99  */
 100 void *av_mallocz(unsigned int size) av_malloc_attrib av_alloc_size(1);
 101
 102 /**
 103  * Duplicates the string s.
 104  * @param s string to be duplicated
 105  * @return Pointer to a newly allocated string containing a
 106  * copy of s or NULL if the string cannot be allocated.
 107  */
 108 char *av_strdup(const char *s) av_malloc_attrib;
 109
 110 /**
 111  * Frees a memory block which has been allocated with av_malloc(z)() or
 112  * av_realloc() and set the pointer pointing to it to NULL.
 113  * @param ptr Pointer to the pointer to the memory block which should
 114  * be freed.
 115  * @see av_free()
 116  */
 117 void av_freep(void *ptr);
 118
 119 #endif /* AVUTIL_MEM_H */