2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of Libav.
6 * Libav 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.
11 * Libav 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.
16 * 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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * memory handling functions
32 #include "attributes.h"
36 * @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 #elif defined(__TI_COMPILER_VERSION__)
45 #define DECLARE_ALIGNED(n,t,v) \
46 AV_PRAGMA(DATA_ALIGN(v,n)) \
47 t __attribute__((aligned(n))) v
48 #define DECLARE_ASM_CONST(n,t,v) \
49 AV_PRAGMA(DATA_ALIGN(v,n)) \
50 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 #elif defined(_MSC_VER)
55 #define DECLARE_ALIGNED(n,t,v) __declspec(align(n)) t v
56 #define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v
58 #define DECLARE_ALIGNED(n,t,v) t v
59 #define DECLARE_ASM_CONST(n,t,v) static const t v
62 #if AV_GCC_VERSION_AT_LEAST(3,1)
63 #define av_malloc_attrib __attribute__((__malloc__))
65 #define av_malloc_attrib
68 #if AV_GCC_VERSION_AT_LEAST(4,3)
69 #define av_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__)))
71 #define av_alloc_size(...)
75 * Allocate a block of size bytes with alignment suitable for all
76 * memory accesses (including vectors if available on the CPU).
77 * @param size Size in bytes for the memory block to be allocated.
78 * @return Pointer to the allocated block, NULL if the block cannot
82 void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1);
85 * Helper function to allocate a block of size * nmemb bytes with
87 * @param nmemb Number of elements
88 * @param size Size of the single element
89 * @return Pointer to the allocated block, NULL if the block cannot
93 av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t size)
95 if (size <= 0 || nmemb >= INT_MAX / size)
97 return av_malloc(nmemb * size);
101 * Allocate or reallocate a block of memory.
102 * If ptr is NULL and size > 0, allocate a new block. If
103 * size is zero, free the memory block pointed to by ptr.
104 * @param ptr Pointer to a memory block already allocated with
105 * av_malloc(z)() or av_realloc() or NULL.
106 * @param size Size in bytes for the memory block to be allocated or
108 * @return Pointer to a newly reallocated block or NULL if the block
109 * cannot be reallocated or the function is used to free the memory block.
110 * @see av_fast_realloc()
112 void *av_realloc(void *ptr, size_t size) av_alloc_size(2);
115 * Free a memory block which has been allocated with av_malloc(z)() or
117 * @param ptr Pointer to the memory block which should be freed.
118 * @note ptr = NULL is explicitly allowed.
119 * @note It is recommended that you use av_freep() instead.
122 void av_free(void *ptr);
125 * Allocate a block of size bytes with alignment suitable for all
126 * memory accesses (including vectors if available on the CPU) and
127 * zero all the bytes of the block.
128 * @param size Size in bytes for the memory block to be allocated.
129 * @return Pointer to the allocated block, NULL if it cannot be allocated.
132 void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1);
135 * Helper function to allocate a block of size * nmemb bytes with
137 * @param nmemb Number of elements
138 * @param size Size of the single element
139 * @return Pointer to the allocated block, NULL if the block cannot
142 * @see av_malloc_array()
144 av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size)
146 if (size <= 0 || nmemb >= INT_MAX / size)
148 return av_mallocz(nmemb * size);
152 * Duplicate the string s.
153 * @param s string to be duplicated
154 * @return Pointer to a newly allocated string containing a
155 * copy of s or NULL if the string cannot be allocated.
157 char *av_strdup(const char *s) av_malloc_attrib;
160 * Free a memory block which has been allocated with av_malloc(z)() or
161 * av_realloc() and set the pointer pointing to it to NULL.
162 * @param ptr Pointer to the pointer to the memory block which should
166 void av_freep(void *ptr);
169 * @brief deliberately overlapping memcpy implementation
170 * @param dst destination buffer
171 * @param back how many bytes back we start (the initial size of the overlapping window)
172 * @param cnt number of bytes to copy, must be >= 0
174 * cnt > back is valid, this will copy the bytes we just copied,
175 * thus creating a repeating pattern with a period length of back.
177 void av_memcpy_backptr(uint8_t *dst, int back, int cnt);
183 #endif /* AVUTIL_MEM_H */