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 mem.h
  23  * Memory handling functions.
  24  */
  25
  26 #ifndef AVUTIL_MEM_H
  27 #define AVUTIL_MEM_H
  28
  29 #if defined(__ICC) || defined(__SUNPRO_C)
  30     #define DECLARE_ALIGNED(n,t,v)      t v __attribute__ ((aligned (n)))
  31     #define DECLARE_ASM_CONST(n,t,v)    const t __attribute__ ((aligned (n))) v
  32 #elif defined(__GNUC__)
  33     #define DECLARE_ALIGNED(n,t,v)      t v __attribute__ ((aligned (n)))
  34     #define DECLARE_ASM_CONST(n,t,v)    static const t v attribute_used __attribute__ ((aligned (n)))
  35 #elif defined(_MSC_VER)
  36     #define DECLARE_ALIGNED(n,t,v)      __declspec(align(n)) t v
  37     #define DECLARE_ASM_CONST(n,t,v)    __declspec(align(n)) static const t v
  38 #elif defined(HAVE_INLINE_ASM)
  39     #error The asm code needs alignment, but we do not know how to do it for this compiler.
  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 #if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
  46     #define av_malloc_attrib __attribute__((__malloc__))
  47 #else
  48     #define av_malloc_attrib
  49 #endif
  50
  51 #if defined(__GNUC__) && (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ > 2)
  52     #define av_alloc_size(n) __attribute__((alloc_size(n)))
  53 #else
  54     #define av_alloc_size(n)
  55 #endif
  56
  57 /**
  58  * Allocate a block of \p size bytes with alignment suitable for all
  59  * memory accesses (including vectors if available on the CPU).
  60  * @param size Size in bytes for the memory block to be allocated.
  61  * @return Pointer to the allocated block, NULL if it cannot allocate
  62  * it.
  63  * @see av_mallocz()
  64  */
  65 void *av_malloc(unsigned int size) av_malloc_attrib av_alloc_size(1);
  66
  67 /**
  68  * Allocate or reallocate a block of memory.
  69  * If \p ptr is NULL and \p size > 0, allocate a new block. If \p
  70  * size is zero, free the memory block pointed by \p ptr.
  71  * @param size Size in bytes for the memory block to be allocated or
  72  * reallocated.
  73  * @param ptr Pointer to a memory block already allocated with
  74  * av_malloc(z)() or av_realloc() or NULL.
  75  * @return Pointer to a newly reallocated block or NULL if it cannot
  76  * reallocate or the function is used to free the memory block.
  77  * @see av_fast_realloc()
  78  */
  79 void *av_realloc(void *ptr, unsigned int size) av_alloc_size(2);
  80
  81 /**
  82  * Free a memory block which has been allocated with av_malloc(z)() or
  83  * av_realloc().
  84  * @param ptr Pointer to the memory block which should be freed.
  85  * @note ptr = NULL is explicitly allowed.
  86  * @note It is recommended that you use av_freep() instead.
  87  * @see av_freep()
  88  */
  89 void av_free(void *ptr);
  90
  91 /**
  92  * Allocate a block of \p size bytes with alignment suitable for all
  93  * memory accesses (including vectors if available on the CPU) and
  94  * set to zeroes all the bytes of the block.
  95  * @param size Size in bytes for the memory block to be allocated.
  96  * @return Pointer to the allocated block, NULL if it cannot allocate
  97  * it.
  98  * @see av_malloc()
  99  */
 100 void *av_mallocz(unsigned int size) av_malloc_attrib av_alloc_size(1);
 101
 102 /**
 103  * Duplicate the string \p s.
 104  * @param s String to be duplicated.
 105  * @return Pointer to a newly allocated string containing a
 106  * copy of \p s or NULL if it cannot be allocated.
 107  */
 108 char *av_strdup(const char *s) av_malloc_attrib;
 109
 110 /**
 111  * Free a memory block which has been allocated with av_malloc(z)() or
 112  * av_realloc() and set to NULL the pointer to it.
 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 */