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
32 #include "attributes.h"
37 * @addtogroup lavu_mem
42 #if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 1110 || defined(__SUNPRO_C)
43 #define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v
44 #define DECLARE_ASM_CONST(n,t,v) const t __attribute__ ((aligned (n))) v
45 #elif defined(__TI_COMPILER_VERSION__)
46 #define DECLARE_ALIGNED(n,t,v) \
47 AV_PRAGMA(DATA_ALIGN(v,n)) \
48 t __attribute__((aligned(n))) v
49 #define DECLARE_ASM_CONST(n,t,v) \
50 AV_PRAGMA(DATA_ALIGN(v,n)) \
51 static const t __attribute__((aligned(n))) v
52 #elif defined(__GNUC__)
53 #define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v
54 #define DECLARE_ASM_CONST(n,t,v) static const t av_used __attribute__ ((aligned (n))) v
55 #elif defined(_MSC_VER)
56 #define DECLARE_ALIGNED(n,t,v) __declspec(align(n)) t v
57 #define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v
59 #define DECLARE_ALIGNED(n,t,v) t v
60 #define DECLARE_ASM_CONST(n,t,v) static const t v
63 #if AV_GCC_VERSION_AT_LEAST(3,1)
64 #define av_malloc_attrib __attribute__((__malloc__))
66 #define av_malloc_attrib
69 #if AV_GCC_VERSION_AT_LEAST(4,3)
70 #define av_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__)))
72 #define av_alloc_size(...)
76 * Allocate a block of size bytes with alignment suitable for all
77 * memory accesses (including vectors if available on the CPU).
78 * @param size Size in bytes for the memory block to be allocated.
79 * @return Pointer to the allocated block, NULL if the block cannot
83 void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1);
86 * Allocate a block of size * nmemb bytes with av_malloc().
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_realloc() or NULL.
106 * @param size Size in bytes of 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 * @note av_realloc() is not guaranteed to maintain the alignment of
111 * pointers originating from the av_malloc() family of functions.
112 * @see av_fast_realloc()
114 void *av_realloc(void *ptr, size_t size) av_alloc_size(2);
117 * Allocate or reallocate a block of memory.
118 * This function does the same thing as av_realloc, except:
119 * - It takes two arguments and checks the result of the multiplication for
121 * - It frees the input block in case of failure, thus avoiding the memory
122 * leak with the classic "buf = realloc(buf); if (!buf) return -1;".
124 void *av_realloc_f(void *ptr, size_t nelem, size_t elsize);
127 * Allocate or reallocate an array.
128 * If ptr is NULL and nmemb > 0, allocate a new block. If
129 * nmemb is zero, free the memory block pointed to by ptr.
130 * @param ptr Pointer to a memory block already allocated with
131 * av_realloc() or NULL.
132 * @param nmemb Number of elements
133 * @param size Size of the single element
134 * @return Pointer to a newly-reallocated block or NULL if the block
135 * cannot be reallocated or the function is used to free the memory block.
136 * @note av_realloc_array() is not guaranteed to maintain the alignment of
137 * pointers originating from the av_malloc() family of functions.
139 av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size);
142 * Allocate or reallocate an array through a pointer to a pointer.
143 * If *ptr is NULL and nmemb > 0, allocate a new block. If
144 * nmemb is zero, free the memory block pointed to by ptr.
145 * @param ptr Pointer to a pointer to a memory block already allocated
146 * with av_realloc(), or pointer to a pointer to NULL.
147 * The pointer is updated on success, or freed on failure.
148 * @param nmemb Number of elements
149 * @param size Size of the single element
150 * @return Zero on success, an AVERROR error code on failure.
151 * @note av_reallocp_array() is not guaranteed to maintain the alignment of
152 * pointers originating from the av_malloc() family of functions.
154 av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size);
157 * Free a memory block which has been allocated with av_malloc(z)() or
159 * @param ptr Pointer to the memory block which should be freed.
160 * @note ptr = NULL is explicitly allowed.
161 * @note It is recommended that you use av_freep() instead.
164 void av_free(void *ptr);
167 * Allocate a block of size bytes with alignment suitable for all
168 * memory accesses (including vectors if available on the CPU) and
169 * zero all the bytes of the block.
170 * @param size Size in bytes for the memory block to be allocated.
171 * @return Pointer to the allocated block, NULL if it cannot be allocated.
174 void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1);
177 * Allocate a block of nmemb * size bytes with alignment suitable for all
178 * memory accesses (including vectors if available on the CPU) and
179 * zero all the bytes of the block.
180 * The allocation will fail if nmemb * size is greater than or equal
184 * @return Pointer to the allocated block, NULL if it cannot be allocated.
186 void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib;
189 * Allocate a block of size * nmemb bytes with av_mallocz().
190 * @param nmemb Number of elements
191 * @param size Size of the single element
192 * @return Pointer to the allocated block, NULL if the block cannot
195 * @see av_malloc_array()
197 av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size)
199 if (size <= 0 || nmemb >= INT_MAX / size)
201 return av_mallocz(nmemb * size);
205 * Duplicate the string s.
206 * @param s string to be duplicated
207 * @return Pointer to a newly-allocated string containing a
208 * copy of s or NULL if the string cannot be allocated.
210 char *av_strdup(const char *s) av_malloc_attrib;
213 * Duplicate the buffer p.
214 * @param p buffer to be duplicated
215 * @return Pointer to a newly allocated buffer containing a
216 * copy of p or NULL if the buffer cannot be allocated.
218 void *av_memdup(const void *p, size_t size);
221 * Free a memory block which has been allocated with av_malloc(z)() or
222 * av_realloc() and set the pointer pointing to it to NULL.
223 * @param ptr Pointer to the pointer to the memory block which should
227 void av_freep(void *ptr);
230 * Add an element to a dynamic array.
232 * The array to grow is supposed to be an array of pointers to
233 * structures, and the element to add must be a pointer to an already
234 * allocated structure.
236 * The array is reallocated when its size reaches powers of 2.
237 * Therefore, the amortized cost of adding an element is constant.
239 * In case of success, the pointer to the array is updated in order to
240 * point to the new grown array, and the number pointed to by nb_ptr
242 * In case of failure, the array is freed, *tab_ptr is set to NULL and
243 * *nb_ptr is set to 0.
245 * @param tab_ptr pointer to the array to grow
246 * @param nb_ptr pointer to the number of elements in the array
247 * @param elem element to add
248 * @see av_dynarray2_add()
250 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem);
253 * Add an element of size elem_size to a dynamic array.
255 * The array is reallocated when its number of elements reaches powers of 2.
256 * Therefore, the amortized cost of adding an element is constant.
258 * In case of success, the pointer to the array is updated in order to
259 * point to the new grown array, and the number pointed to by nb_ptr
261 * In case of failure, the array is freed, *tab_ptr is set to NULL and
262 * *nb_ptr is set to 0.
264 * @param tab_ptr pointer to the array to grow
265 * @param nb_ptr pointer to the number of elements in the array
266 * @param elem_size size in bytes of the elements in the array
267 * @param elem_data pointer to the data of the element to add. If NULL, the space of
268 * the new added element is not filled.
269 * @return pointer to the data of the element to copy in the new allocated space.
270 * If NULL, the new allocated space is left uninitialized."
271 * @see av_dynarray_add()
273 void *av_dynarray2_add(void **tab_ptr, int *nb_ptr, size_t elem_size,
274 const uint8_t *elem_data);
277 * Multiply two size_t values checking for overflow.
278 * @return 0 if success, AVERROR(EINVAL) if overflow.
280 static inline int av_size_mult(size_t a, size_t b, size_t *r)
283 /* Hack inspired from glibc: only try the division if nelem and elsize
284 * are both greater than sqrt(SIZE_MAX). */
285 if ((a | b) >= ((size_t)1 << (sizeof(size_t) * 4)) && a && t / a != b)
286 return AVERROR(EINVAL);
292 * Set the maximum size that may me allocated in one block.
294 void av_max_alloc(size_t max);
297 * deliberately overlapping memcpy implementation
298 * @param dst destination buffer
299 * @param back how many bytes back we start (the initial size of the overlapping window), must be > 0
300 * @param cnt number of bytes to copy, must be >= 0
302 * cnt > back is valid, this will copy the bytes we just copied,
303 * thus creating a repeating pattern with a period length of back.
305 void av_memcpy_backptr(uint8_t *dst, int back, int cnt);
311 #endif /* AVUTIL_MEM_H */