2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
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.
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.
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
23 * memory handling functions
31 #include "attributes.h"
36 * @addtogroup lavu_mem
41 #if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 1110 || 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 * Allocate or reallocate a block of memory.
116 * This function does the same thing as av_realloc, except:
117 * - It takes two arguments and checks the result of the multiplication for
119 * - It frees the input block in case of failure, thus avoiding the memory
120 * leak with the classic "buf = realloc(buf); if (!buf) return -1;".
122 void *av_realloc_f(void *ptr, size_t nelem, size_t elsize);
125 * Free a memory block which has been allocated with av_malloc(z)() or
127 * @param ptr Pointer to the memory block which should be freed.
128 * @note ptr = NULL is explicitly allowed.
129 * @note It is recommended that you use av_freep() instead.
132 void av_free(void *ptr);
135 * Allocate a block of size bytes with alignment suitable for all
136 * memory accesses (including vectors if available on the CPU) and
137 * zero all the bytes of the block.
138 * @param size Size in bytes for the memory block to be allocated.
139 * @return Pointer to the allocated block, NULL if it cannot be allocated.
142 void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1);
145 * Allocate a block of nmemb * size bytes with alignment suitable for all
146 * memory accesses (including vectors if available on the CPU) and
147 * zero all the bytes of the block.
148 * The allocation will fail if nmemb * size is greater than or equal
152 * @return Pointer to the allocated block, NULL if it cannot be allocated.
154 void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib;
157 * Helper function to allocate a block of size * nmemb bytes with
159 * @param nmemb Number of elements
160 * @param size Size of the single element
161 * @return Pointer to the allocated block, NULL if the block cannot
164 * @see av_malloc_array()
166 av_alloc_size(1,2) static inline void *av_mallocz_array(size_t nmemb, size_t size)
168 if (size <= 0 || nmemb >= INT_MAX / size)
170 return av_mallocz(nmemb * size);
174 * Duplicate the string s.
175 * @param s string to be duplicated
176 * @return Pointer to a newly allocated string containing a
177 * copy of s or NULL if the string cannot be allocated.
179 char *av_strdup(const char *s) av_malloc_attrib;
182 * Free a memory block which has been allocated with av_malloc(z)() or
183 * av_realloc() and set the pointer pointing to it to NULL.
184 * @param ptr Pointer to the pointer to the memory block which should
188 void av_freep(void *ptr);
191 * Add an element to a dynamic array.
193 * @param tab_ptr Pointer to the array.
194 * @param nb_ptr Pointer to the number of elements in the array.
195 * @param elem Element to be added.
197 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem);
200 * Multiply two size_t values checking for overflow.
201 * @return 0 if success, AVERROR(EINVAL) if overflow.
203 static inline int av_size_mult(size_t a, size_t b, size_t *r)
206 /* Hack inspired from glibc: only try the division if nelem and elsize
207 * are both greater than sqrt(SIZE_MAX). */
208 if ((a | b) >= ((size_t)1 << (sizeof(size_t) * 4)) && a && t / a != b)
209 return AVERROR(EINVAL);
215 * Set the maximum size that may me allocated in one block.
217 void av_max_alloc(size_t max);
223 #endif /* AVUTIL_MEM_H */