mem.h 6.99 KB
Newer Older
1 2 3
/*
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
4
 * This file is part of Libav.
5
 *
6
 * Libav is free software; you can redistribute it and/or
7 8 9 10
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
11
 * Libav is distributed in the hope that it will be useful,
12 13 14 15 16
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
17
 * License along with Libav; if not, write to the Free Software
18 19 20 21
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
22
 * @file
23
 * memory handling functions
24 25
 */

26 27
#ifndef AVUTIL_MEM_H
#define AVUTIL_MEM_H
28

29
#include <limits.h>
30
#include <stdint.h>
31

32
#include "attributes.h"
33
#include "avutil.h"
34

35 36 37 38 39 40
/**
 * @addtogroup lavu_mem
 * @{
 */


41
#if defined(__ICC) && __ICC < 1200 || defined(__SUNPRO_C)
42
    #define DECLARE_ALIGNED(n,t,v)      t __attribute__ ((aligned (n))) v
43
    #define DECLARE_ASM_CONST(n,t,v)    const t __attribute__ ((aligned (n))) v
44 45 46 47 48 49 50
#elif defined(__TI_COMPILER_VERSION__)
    #define DECLARE_ALIGNED(n,t,v)                      \
        AV_PRAGMA(DATA_ALIGN(v,n))                      \
        t __attribute__((aligned(n))) v
    #define DECLARE_ASM_CONST(n,t,v)                    \
        AV_PRAGMA(DATA_ALIGN(v,n))                      \
        static const t __attribute__((aligned(n))) v
51
#elif defined(__GNUC__)
52
    #define DECLARE_ALIGNED(n,t,v)      t __attribute__ ((aligned (n))) v
53
    #define DECLARE_ASM_CONST(n,t,v)    static const t av_used __attribute__ ((aligned (n))) v
54 55 56 57 58 59 60 61
#elif defined(_MSC_VER)
    #define DECLARE_ALIGNED(n,t,v)      __declspec(align(n)) t v
    #define DECLARE_ASM_CONST(n,t,v)    __declspec(align(n)) static const t v
#else
    #define DECLARE_ALIGNED(n,t,v)      t v
    #define DECLARE_ASM_CONST(n,t,v)    static const t v
#endif

62
#if AV_GCC_VERSION_AT_LEAST(3,1)
63 64 65 66 67
    #define av_malloc_attrib __attribute__((__malloc__))
#else
    #define av_malloc_attrib
#endif

68
#if AV_GCC_VERSION_AT_LEAST(4,3)
69
    #define av_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__)))
70
#else
71
    #define av_alloc_size(...)
72 73
#endif

74
/**
75
 * Allocate a block of size bytes with alignment suitable for all
76 77
 * memory accesses (including vectors if available on the CPU).
 * @param size Size in bytes for the memory block to be allocated.
78 79
 * @return Pointer to the allocated block, NULL if the block cannot
 * be allocated.
80
 * @see av_mallocz()
81
 */
82
void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1);
83

84 85 86 87 88 89 90 91 92
/**
 * Helper function to allocate a block of size * nmemb bytes with
 * using av_malloc()
 * @param nmemb Number of elements
 * @param size Size of the single element
 * @return Pointer to the allocated block, NULL if the block cannot
 * be allocated.
 * @see av_malloc()
 */
93
av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t size)
94 95 96 97 98 99
{
    if (size <= 0 || nmemb >= INT_MAX / size)
        return NULL;
    return av_malloc(nmemb * size);
}

100
/**
101 102 103
 * Allocate or reallocate a block of memory.
 * If ptr is NULL and size > 0, allocate a new block. If
 * size is zero, free the memory block pointed to by ptr.
104 105
 * @param ptr Pointer to a memory block already allocated with
 * av_malloc(z)() or av_realloc() or NULL.
106 107
 * @param size Size in bytes for the memory block to be allocated or
 * reallocated.
108 109
 * @return Pointer to a newly reallocated block or NULL if the block
 * cannot be reallocated or the function is used to free the memory block.
110
 * @see av_fast_realloc()
111
 */
112
void *av_realloc(void *ptr, size_t size) av_alloc_size(2);
113

114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139
/**
 * Allocate or reallocate an array.
 * If ptr is NULL and nmemb > 0, allocate a new block. If
 * nmemb is zero, free the memory block pointed to by ptr.
 * @param ptr Pointer to a memory block already allocated with
 * av_malloc(z)() or av_realloc() or NULL.
 * @param nmemb Number of elements
 * @param size Size of the single element
 * @return Pointer to a newly reallocated block or NULL if the block
 * cannot be reallocated or the function is used to free the memory block.
 */
av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size);

/**
 * Allocate or reallocate an array.
 * If *ptr is NULL and nmemb > 0, allocate a new block. If
 * nmemb is zero, free the memory block pointed to by ptr.
 * @param ptr Pointer to a pointer to a memory block already allocated
 * with av_malloc(z)() or av_realloc(), or pointer to a pointer to NULL.
 * The pointer is updated on success, or freed on failure.
 * @param nmemb Number of elements
 * @param size Size of the single element
 * @return Zero on success, an AVERROR error code on failure.
 */
av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size);

140
/**
141
 * Free a memory block which has been allocated with av_malloc(z)() or
142 143
 * av_realloc().
 * @param ptr Pointer to the memory block which should be freed.
144 145
 * @note ptr = NULL is explicitly allowed.
 * @note It is recommended that you use av_freep() instead.
146
 * @see av_freep()
147 148 149
 */
void av_free(void *ptr);

150
/**
151
 * Allocate a block of size bytes with alignment suitable for all
152
 * memory accesses (including vectors if available on the CPU) and
153
 * zero all the bytes of the block.
154
 * @param size Size in bytes for the memory block to be allocated.
155
 * @return Pointer to the allocated block, NULL if it cannot be allocated.
156 157
 * @see av_malloc()
 */
158
void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1);
159

160 161 162 163 164 165 166 167 168 169
/**
 * Helper function to allocate a block of size * nmemb bytes with
 * using av_mallocz()
 * @param nmemb Number of elements
 * @param size Size of the single element
 * @return Pointer to the allocated block, NULL if the block cannot
 * be allocated.
 * @see av_mallocz()
 * @see av_malloc_array()
 */
170
av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size)
171 172 173 174 175 176
{
    if (size <= 0 || nmemb >= INT_MAX / size)
        return NULL;
    return av_mallocz(nmemb * size);
}

177
/**
178
 * Duplicate the string s.
179
 * @param s string to be duplicated
180
 * @return Pointer to a newly allocated string containing a
181
 * copy of s or NULL if the string cannot be allocated.
182
 */
183
char *av_strdup(const char *s) av_malloc_attrib;
184 185

/**
186
 * Free a memory block which has been allocated with av_malloc(z)() or
187
 * av_realloc() and set the pointer pointing to it to NULL.
188 189 190
 * @param ptr Pointer to the pointer to the memory block which should
 * be freed.
 * @see av_free()
191 192 193
 */
void av_freep(void *ptr);

194 195 196 197 198 199 200 201 202 203 204
/**
 * @brief deliberately overlapping memcpy implementation
 * @param dst destination buffer
 * @param back how many bytes back we start (the initial size of the overlapping window)
 * @param cnt number of bytes to copy, must be >= 0
 *
 * cnt > back is valid, this will copy the bytes we just copied,
 * thus creating a repeating pattern with a period length of back.
 */
void av_memcpy_backptr(uint8_t *dst, int back, int cnt);

205 206 207 208
/**
 * @}
 */

209
#endif /* AVUTIL_MEM_H */