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 bytes with alignment suitable for all
87 * memory accesses (including vectors if available on the CPU) and
88 * zero all the bytes of the block.
89 * @param size Size in bytes for the memory block to be allocated.
90 * @return Pointer to the allocated block, NULL if it cannot be allocated.
93 void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1);
96 * Allocate a block of size * nmemb bytes with av_malloc().
97 * @param nmemb Number of elements
98 * @param size Size of the single element
99 * @return Pointer to the allocated block, NULL if the block cannot
103 av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t size)
105 if (!size || nmemb >= INT_MAX / size)
107 return av_malloc(nmemb * size);
111 * Allocate a block of size * nmemb bytes with av_mallocz().
112 * @param nmemb Number of elements
113 * @param size Size of the single element
114 * @return Pointer to the allocated block, NULL if the block cannot
117 * @see av_malloc_array()
119 av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size)
121 if (!size || nmemb >= INT_MAX / size)
123 return av_mallocz(nmemb * size);
127 * Allocate a block of nmemb * size bytes with alignment suitable for all
128 * memory accesses (including vectors if available on the CPU) and
129 * zero all the bytes of the block.
130 * The allocation will fail if nmemb * size is greater than or equal
134 * @return Pointer to the allocated block, NULL if it cannot be allocated.
136 void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib;
139 * Allocate or reallocate a block of memory.
140 * If ptr is NULL and size > 0, allocate a new block. If
141 * size is zero, free the memory block pointed to by ptr.
142 * @param ptr Pointer to a memory block already allocated with
143 * av_realloc() or NULL.
144 * @param size Size in bytes of the memory block to be allocated or
146 * @return Pointer to a newly-reallocated block or NULL if the block
147 * cannot be reallocated or the function is used to free the memory block.
148 * @warning Pointers originating from the av_malloc() family of functions must
149 * not be passed to av_realloc(). The former can be implemented using
150 * memalign() (or other functions), and there is no guarantee that
151 * pointers from such functions can be passed to realloc() at all.
152 * The situation is undefined according to POSIX and may crash with
153 * some libc implementations.
154 * @see av_fast_realloc()
156 void *av_realloc(void *ptr, size_t size) av_alloc_size(2);
159 * Allocate or reallocate a block of memory.
160 * If *ptr is NULL and size > 0, allocate a new block. If
161 * size is zero, free the memory block pointed to by ptr.
162 * @param ptr Pointer to a pointer to a memory block already allocated
163 * with av_realloc(), or pointer to a pointer to NULL.
164 * The pointer is updated on success, or freed on failure.
165 * @param size Size in bytes for the memory block to be allocated or
167 * @return Zero on success, an AVERROR error code on failure.
168 * @warning Pointers originating from the av_malloc() family of functions must
169 * not be passed to av_reallocp(). The former can be implemented using
170 * memalign() (or other functions), and there is no guarantee that
171 * pointers from such functions can be passed to realloc() at all.
172 * The situation is undefined according to POSIX and may crash with
173 * some libc implementations.
175 av_warn_unused_result
176 int av_reallocp(void *ptr, size_t size);
179 * Allocate or reallocate a block of memory.
180 * This function does the same thing as av_realloc, except:
181 * - It takes two arguments and checks the result of the multiplication for
183 * - It frees the input block in case of failure, thus avoiding the memory
184 * leak with the classic "buf = realloc(buf); if (!buf) return -1;".
186 void *av_realloc_f(void *ptr, size_t nelem, size_t elsize);
189 * Allocate or reallocate an array.
190 * If ptr is NULL and nmemb > 0, allocate a new block. If
191 * nmemb is zero, free the memory block pointed to by ptr.
192 * @param ptr Pointer to a memory block already allocated with
193 * av_realloc() or NULL.
194 * @param nmemb Number of elements
195 * @param size Size of the single element
196 * @return Pointer to a newly-reallocated block or NULL if the block
197 * cannot be reallocated or the function is used to free the memory block.
198 * @warning Pointers originating from the av_malloc() family of functions must
199 * not be passed to av_realloc(). The former can be implemented using
200 * memalign() (or other functions), and there is no guarantee that
201 * pointers from such functions can be passed to realloc() at all.
202 * The situation is undefined according to POSIX and may crash with
203 * some libc implementations.
205 av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size);
208 * Allocate or reallocate an array through a pointer to a pointer.
209 * If *ptr is NULL and nmemb > 0, allocate a new block. If
210 * nmemb is zero, free the memory block pointed to by ptr.
211 * @param ptr Pointer to a pointer to a memory block already allocated
212 * with av_realloc(), or pointer to a pointer to NULL.
213 * The pointer is updated on success, or freed on failure.
214 * @param nmemb Number of elements
215 * @param size Size of the single element
216 * @return Zero on success, an AVERROR error code on failure.
217 * @warning Pointers originating from the av_malloc() family of functions must
218 * not be passed to av_realloc(). The former can be implemented using
219 * memalign() (or other functions), and there is no guarantee that
220 * pointers from such functions can be passed to realloc() at all.
221 * The situation is undefined according to POSIX and may crash with
222 * some libc implementations.
224 av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size);
227 * Reallocate the given block if it is not large enough, otherwise do nothing.
231 void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size);
234 * Allocate a buffer, reusing the given one if large enough.
236 * Contrary to av_fast_realloc the current buffer contents might not be
237 * preserved and on error the old buffer is freed, thus no special
238 * handling to avoid memleaks is necessary.
240 * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
241 * @param size size of the buffer *ptr points to
242 * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
243 * *size 0 if an error occurred.
245 void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size);
248 * Allocate a buffer, reusing the given one if large enough.
250 * All newly allocated space is initially cleared
251 * Contrary to av_fast_realloc the current buffer contents might not be
252 * preserved and on error the old buffer is freed, thus no special
253 * handling to avoid memleaks is necessary.
255 * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
256 * @param size size of the buffer *ptr points to
257 * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
258 * *size 0 if an error occurred.
260 void av_fast_mallocz(void *ptr, unsigned int *size, size_t min_size);
263 * Free a memory block which has been allocated with av_malloc(z)() or
265 * @param ptr Pointer to the memory block which should be freed.
266 * @note ptr = NULL is explicitly allowed.
267 * @note It is recommended that you use av_freep() instead.
270 void av_free(void *ptr);
273 * Free a memory block which has been allocated with av_malloc(z)() or
274 * av_realloc() and set the pointer pointing to it to NULL.
275 * @param ptr Pointer to the pointer to the memory block which should
277 * @note passing a pointer to a NULL pointer is safe and leads to no action.
280 void av_freep(void *ptr);
283 * Duplicate the string s.
284 * @param s string to be duplicated
285 * @return Pointer to a newly-allocated string containing a
286 * copy of s or NULL if the string cannot be allocated.
288 char *av_strdup(const char *s) av_malloc_attrib;
291 * Duplicate a substring of the string s.
292 * @param s string to be duplicated
293 * @param len the maximum length of the resulting string (not counting the
295 * @return Pointer to a newly-allocated string containing a
296 * copy of s or NULL if the string cannot be allocated.
298 char *av_strndup(const char *s, size_t len) av_malloc_attrib;
301 * Duplicate the buffer p.
302 * @param p buffer to be duplicated
303 * @return Pointer to a newly allocated buffer containing a
304 * copy of p or NULL if the buffer cannot be allocated.
306 void *av_memdup(const void *p, size_t size);
309 * deliberately overlapping memcpy implementation
310 * @param dst destination buffer
311 * @param back how many bytes back we start (the initial size of the overlapping window), must be > 0
312 * @param cnt number of bytes to copy, must be >= 0
314 * cnt > back is valid, this will copy the bytes we just copied,
315 * thus creating a repeating pattern with a period length of back.
317 void av_memcpy_backptr(uint8_t *dst, int back, int cnt);
320 * Add an element to a dynamic array.
322 * The array to grow is supposed to be an array of pointers to
323 * structures, and the element to add must be a pointer to an already
324 * allocated structure.
326 * The array is reallocated when its size reaches powers of 2.
327 * Therefore, the amortized cost of adding an element is constant.
329 * In case of success, the pointer to the array is updated in order to
330 * point to the new grown array, and the number pointed to by nb_ptr
332 * In case of failure, the array is freed, *tab_ptr is set to NULL and
333 * *nb_ptr is set to 0.
335 * @param tab_ptr pointer to the array to grow
336 * @param nb_ptr pointer to the number of elements in the array
337 * @param elem element to add
338 * @see av_dynarray_add_nofree(), av_dynarray2_add()
340 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem);
343 * Add an element to a dynamic array.
345 * Function has the same functionality as av_dynarray_add(),
346 * but it doesn't free memory on fails. It returns error code
347 * instead and leave current buffer untouched.
349 * @param tab_ptr pointer to the array to grow
350 * @param nb_ptr pointer to the number of elements in the array
351 * @param elem element to add
352 * @return >=0 on success, negative otherwise.
353 * @see av_dynarray_add(), av_dynarray2_add()
355 av_warn_unused_result
356 int av_dynarray_add_nofree(void *tab_ptr, int *nb_ptr, void *elem);
359 * Add an element of size elem_size to a dynamic array.
361 * The array is reallocated when its number of elements reaches powers of 2.
362 * Therefore, the amortized cost of adding an element is constant.
364 * In case of success, the pointer to the array is updated in order to
365 * point to the new grown array, and the number pointed to by nb_ptr
367 * In case of failure, the array is freed, *tab_ptr is set to NULL and
368 * *nb_ptr is set to 0.
370 * @param tab_ptr pointer to the array to grow
371 * @param nb_ptr pointer to the number of elements in the array
372 * @param elem_size size in bytes of the elements in the array
373 * @param elem_data pointer to the data of the element to add. If NULL, the space of
374 * the new added element is not filled.
375 * @return pointer to the data of the element to copy in the new allocated space.
376 * If NULL, the new allocated space is left uninitialized."
377 * @see av_dynarray_add(), av_dynarray_add_nofree()
379 void *av_dynarray2_add(void **tab_ptr, int *nb_ptr, size_t elem_size,
380 const uint8_t *elem_data);
383 * Multiply two size_t values checking for overflow.
384 * @return 0 if success, AVERROR(EINVAL) if overflow.
386 static inline int av_size_mult(size_t a, size_t b, size_t *r)
389 /* Hack inspired from glibc: don't try the division if nelem and elsize
390 * are both less than sqrt(SIZE_MAX). */
391 if ((a | b) >= ((size_t)1 << (sizeof(size_t) * 4)) && a && t / a != b)
392 return AVERROR(EINVAL);
398 * Set the maximum size that may me allocated in one block.
400 void av_max_alloc(size_t max);
406 #endif /* AVUTIL_MEM_H */