1/* 2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> 3 * 4 * This file is part of FFmpeg. 5 * 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. 10 * 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. 15 * 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 19 */ 20 21/** 22 * @file 23 * memory handling functions 24 */ 25 26#ifndef AVUTIL_MEM_H 27#define AVUTIL_MEM_H 28 29#include <limits.h> 30#include <stdint.h> 31 32#include "attributes.h" 33#include "error.h" 34#include "avutil.h" 35 36/** 37 * @addtogroup lavu_mem 38 * @{ 39 */ 40 41 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 58#else 59 #define DECLARE_ALIGNED(n,t,v) t v 60 #define DECLARE_ASM_CONST(n,t,v) static const t v 61#endif 62 63#if AV_GCC_VERSION_AT_LEAST(3,1) 64 #define av_malloc_attrib __attribute__((__malloc__)) 65#else 66 #define av_malloc_attrib 67#endif 68 69#if AV_GCC_VERSION_AT_LEAST(4,3) 70 #define av_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__))) 71#else 72 #define av_alloc_size(...) 73#endif 74 75/** 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 80 * be allocated. 81 * @see av_mallocz() 82 */ 83void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1); 84 85/** 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 90 * be allocated. 91 * @see av_malloc() 92 */ 93av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t size) 94{ 95 if (!size || nmemb >= INT_MAX / size) 96 return NULL; 97 return av_malloc(nmemb * size); 98} 99 100/** 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 107 * reallocated. 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 * @warning Pointers originating from the av_malloc() family of functions must 111 * not be passed to av_realloc(). The former can be implemented using 112 * memalign() (or other functions), and there is no guarantee that 113 * pointers from such functions can be passed to realloc() at all. 114 * The situation is undefined according to POSIX and may crash with 115 * some libc implementations. 116 * @see av_fast_realloc() 117 */ 118void *av_realloc(void *ptr, size_t size) av_alloc_size(2); 119 120/** 121 * Allocate or reallocate a block of memory. 122 * This function does the same thing as av_realloc, except: 123 * - It takes two arguments and checks the result of the multiplication for 124 * integer overflow. 125 * - It frees the input block in case of failure, thus avoiding the memory 126 * leak with the classic "buf = realloc(buf); if (!buf) return -1;". 127 */ 128void *av_realloc_f(void *ptr, size_t nelem, size_t elsize); 129 130/** 131 * Allocate or reallocate a block of memory. 132 * If *ptr is NULL and size > 0, allocate a new block. If 133 * size is zero, free the memory block pointed to by ptr. 134 * @param ptr Pointer to a pointer to a memory block already allocated 135 * with av_realloc(), or pointer to a pointer to NULL. 136 * The pointer is updated on success, or freed on failure. 137 * @param size Size in bytes for the memory block to be allocated or 138 * reallocated 139 * @return Zero on success, an AVERROR error code on failure. 140 * @warning Pointers originating from the av_malloc() family of functions must 141 * not be passed to av_reallocp(). The former can be implemented using 142 * memalign() (or other functions), and there is no guarantee that 143 * pointers from such functions can be passed to realloc() at all. 144 * The situation is undefined according to POSIX and may crash with 145 * some libc implementations. 146 */ 147int av_reallocp(void *ptr, size_t size); 148 149/** 150 * Allocate or reallocate an array. 151 * If ptr is NULL and nmemb > 0, allocate a new block. If 152 * nmemb is zero, free the memory block pointed to by ptr. 153 * @param ptr Pointer to a memory block already allocated with 154 * av_realloc() or NULL. 155 * @param nmemb Number of elements 156 * @param size Size of the single element 157 * @return Pointer to a newly-reallocated block or NULL if the block 158 * cannot be reallocated or the function is used to free the memory block. 159 * @warning Pointers originating from the av_malloc() family of functions must 160 * not be passed to av_realloc(). The former can be implemented using 161 * memalign() (or other functions), and there is no guarantee that 162 * pointers from such functions can be passed to realloc() at all. 163 * The situation is undefined according to POSIX and may crash with 164 * some libc implementations. 165 */ 166av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size); 167 168/** 169 * Allocate or reallocate an array through a pointer to a pointer. 170 * If *ptr is NULL and nmemb > 0, allocate a new block. If 171 * nmemb is zero, free the memory block pointed to by ptr. 172 * @param ptr Pointer to a pointer to a memory block already allocated 173 * with av_realloc(), or pointer to a pointer to NULL. 174 * The pointer is updated on success, or freed on failure. 175 * @param nmemb Number of elements 176 * @param size Size of the single element 177 * @return Zero on success, an AVERROR error code on failure. 178 * @warning Pointers originating from the av_malloc() family of functions must 179 * not be passed to av_realloc(). The former can be implemented using 180 * memalign() (or other functions), and there is no guarantee that 181 * pointers from such functions can be passed to realloc() at all. 182 * The situation is undefined according to POSIX and may crash with 183 * some libc implementations. 184 */ 185av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size); 186 187/** 188 * Free a memory block which has been allocated with av_malloc(z)() or 189 * av_realloc(). 190 * @param ptr Pointer to the memory block which should be freed. 191 * @note ptr = NULL is explicitly allowed. 192 * @note It is recommended that you use av_freep() instead. 193 * @see av_freep() 194 */ 195void av_free(void *ptr); 196 197/** 198 * Allocate a block of size bytes with alignment suitable for all 199 * memory accesses (including vectors if available on the CPU) and 200 * zero all the bytes of the block. 201 * @param size Size in bytes for the memory block to be allocated. 202 * @return Pointer to the allocated block, NULL if it cannot be allocated. 203 * @see av_malloc() 204 */ 205void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1); 206 207/** 208 * Allocate a block of nmemb * size bytes with alignment suitable for all 209 * memory accesses (including vectors if available on the CPU) and 210 * zero all the bytes of the block. 211 * The allocation will fail if nmemb * size is greater than or equal 212 * to INT_MAX. 213 * @param nmemb 214 * @param size 215 * @return Pointer to the allocated block, NULL if it cannot be allocated. 216 */ 217void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib; 218 219/** 220 * Allocate a block of size * nmemb bytes with av_mallocz(). 221 * @param nmemb Number of elements 222 * @param size Size of the single element 223 * @return Pointer to the allocated block, NULL if the block cannot 224 * be allocated. 225 * @see av_mallocz() 226 * @see av_malloc_array() 227 */ 228av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size) 229{ 230 if (!size || nmemb >= INT_MAX / size) 231 return NULL; 232 return av_mallocz(nmemb * size); 233} 234 235/** 236 * Duplicate the string s. 237 * @param s string to be duplicated 238 * @return Pointer to a newly-allocated string containing a 239 * copy of s or NULL if the string cannot be allocated. 240 */ 241char *av_strdup(const char *s) av_malloc_attrib; 242 243/** 244 * Duplicate the buffer p. 245 * @param p buffer to be duplicated 246 * @return Pointer to a newly allocated buffer containing a 247 * copy of p or NULL if the buffer cannot be allocated. 248 */ 249void *av_memdup(const void *p, size_t size); 250 251/** 252 * Free a memory block which has been allocated with av_malloc(z)() or 253 * av_realloc() and set the pointer pointing to it to NULL. 254 * @param ptr Pointer to the pointer to the memory block which should 255 * be freed. 256 * @see av_free() 257 */ 258void av_freep(void *ptr); 259 260/** 261 * Add an element to a dynamic array. 262 * 263 * The array to grow is supposed to be an array of pointers to 264 * structures, and the element to add must be a pointer to an already 265 * allocated structure. 266 * 267 * The array is reallocated when its size reaches powers of 2. 268 * Therefore, the amortized cost of adding an element is constant. 269 * 270 * In case of success, the pointer to the array is updated in order to 271 * point to the new grown array, and the number pointed to by nb_ptr 272 * is incremented. 273 * In case of failure, the array is freed, *tab_ptr is set to NULL and 274 * *nb_ptr is set to 0. 275 * 276 * @param tab_ptr pointer to the array to grow 277 * @param nb_ptr pointer to the number of elements in the array 278 * @param elem element to add 279 * @see av_dynarray_add_nofree(), av_dynarray2_add() 280 */ 281void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem); 282 283/** 284 * Add an element to a dynamic array. 285 * 286 * Function has the same functionality as av_dynarray_add(), 287 * but it doesn't free memory on fails. It returns error code 288 * instead and leave current buffer untouched. 289 * 290 * @param tab_ptr pointer to the array to grow 291 * @param nb_ptr pointer to the number of elements in the array 292 * @param elem element to add 293 * @return >=0 on success, negative otherwise. 294 * @see av_dynarray_add(), av_dynarray2_add() 295 */ 296int av_dynarray_add_nofree(void *tab_ptr, int *nb_ptr, void *elem); 297 298/** 299 * Add an element of size elem_size to a dynamic array. 300 * 301 * The array is reallocated when its number of elements reaches powers of 2. 302 * Therefore, the amortized cost of adding an element is constant. 303 * 304 * In case of success, the pointer to the array is updated in order to 305 * point to the new grown array, and the number pointed to by nb_ptr 306 * is incremented. 307 * In case of failure, the array is freed, *tab_ptr is set to NULL and 308 * *nb_ptr is set to 0. 309 * 310 * @param tab_ptr pointer to the array to grow 311 * @param nb_ptr pointer to the number of elements in the array 312 * @param elem_size size in bytes of the elements in the array 313 * @param elem_data pointer to the data of the element to add. If NULL, the space of 314 * the new added element is not filled. 315 * @return pointer to the data of the element to copy in the new allocated space. 316 * If NULL, the new allocated space is left uninitialized." 317 * @see av_dynarray_add(), av_dynarray_add_nofree() 318 */ 319void *av_dynarray2_add(void **tab_ptr, int *nb_ptr, size_t elem_size, 320 const uint8_t *elem_data); 321 322/** 323 * Multiply two size_t values checking for overflow. 324 * @return 0 if success, AVERROR(EINVAL) if overflow. 325 */ 326static inline int av_size_mult(size_t a, size_t b, size_t *r) 327{ 328 size_t t = a * b; 329 /* Hack inspired from glibc: only try the division if nelem and elsize 330 * are both greater than sqrt(SIZE_MAX). */ 331 if ((a | b) >= ((size_t)1 << (sizeof(size_t) * 4)) && a && t / a != b) 332 return AVERROR(EINVAL); 333 *r = t; 334 return 0; 335} 336 337/** 338 * Set the maximum size that may me allocated in one block. 339 */ 340void av_max_alloc(size_t max); 341 342/** 343 * deliberately overlapping memcpy implementation 344 * @param dst destination buffer 345 * @param back how many bytes back we start (the initial size of the overlapping window), must be > 0 346 * @param cnt number of bytes to copy, must be >= 0 347 * 348 * cnt > back is valid, this will copy the bytes we just copied, 349 * thus creating a repeating pattern with a period length of back. 350 */ 351void av_memcpy_backptr(uint8_t *dst, int back, int cnt); 352 353/** 354 * Reallocate the given block if it is not large enough, otherwise do nothing. 355 * 356 * @see av_realloc 357 */ 358void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size); 359 360/** 361 * Allocate a buffer, reusing the given one if large enough. 362 * 363 * Contrary to av_fast_realloc the current buffer contents might not be 364 * preserved and on error the old buffer is freed, thus no special 365 * handling to avoid memleaks is necessary. 366 * 367 * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer 368 * @param size size of the buffer *ptr points to 369 * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and 370 * *size 0 if an error occurred. 371 */ 372void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size); 373 374/** 375 * @} 376 */ 377 378#endif /* AVUTIL_MEM_H */ 379