/* * copyright (c) 2006 Michael Niedermayer * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * memory handling functions */ #ifndef AVUTIL_MEM_H #define AVUTIL_MEM_H #include #include #include "attributes.h" #include "avutil.h" /** * @addtogroup lavu_mem * @{ */ #if defined(__ICC) && __ICC < 1200 || defined(__SUNPRO_C) #define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v #define DECLARE_ASM_CONST(n,t,v) const t __attribute__ ((aligned (n))) v #elif defined(__TI_COMPILER_VERSION__) #define DECLARE_ALIGNED(n,t,v) \ AV_PRAGMA(DATA_ALIGN(v,n)) \ t __attribute__((aligned(n))) v #define DECLARE_ASM_CONST(n,t,v) \ AV_PRAGMA(DATA_ALIGN(v,n)) \ static const t __attribute__((aligned(n))) v #elif defined(__GNUC__) #define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v #define DECLARE_ASM_CONST(n,t,v) static const t av_used __attribute__ ((aligned (n))) v #elif defined(_MSC_VER) #define DECLARE_ALIGNED(n,t,v) __declspec(align(n)) t v #define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v #else #define DECLARE_ALIGNED(n,t,v) t v #define DECLARE_ASM_CONST(n,t,v) static const t v #endif #if AV_GCC_VERSION_AT_LEAST(3,1) #define av_malloc_attrib __attribute__((__malloc__)) #else #define av_malloc_attrib #endif #if AV_GCC_VERSION_AT_LEAST(4,3) #define av_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__))) #else #define av_alloc_size(...) #endif /** * Allocate a block of size bytes with alignment suitable for all * memory accesses (including vectors if available on the CPU). * @param size Size in bytes for the memory block to be allocated. * @return Pointer to the allocated block, NULL if the block cannot * be allocated. * @see av_mallocz() */ void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1); /** * Allocate a block of size * nmemb bytes with av_malloc(). * @param nmemb Number of elements * @param size Size of the single element * @return Pointer to the allocated block, NULL if the block cannot * be allocated. * @see av_malloc() */ av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t size) { if (!size || nmemb >= INT_MAX / size) return NULL; return av_malloc(nmemb * size); } /** * Allocate or reallocate a block of memory. * If ptr is NULL and size > 0, allocate a new block. If * size is zero, free the memory block pointed to by ptr. * @param ptr Pointer to a memory block already allocated with * av_realloc() or NULL. * @param size Size in bytes of the memory block to be allocated or * reallocated. * @return Pointer to a newly-reallocated block or NULL if the block * cannot be reallocated or the function is used to free the memory block. * @warning Pointers originating from the av_malloc() family of functions must * not be passed to av_realloc(). The former can be implemented using * memalign() (or other functions), and there is no guarantee that * pointers from such functions can be passed to realloc() at all. * The situation is undefined according to POSIX and may crash with * some libc implementations. * @see av_fast_realloc() */ void *av_realloc(void *ptr, size_t size) av_alloc_size(2); /** * Allocate or reallocate a block of memory. * If *ptr is NULL and size > 0, allocate a new block. If * size is zero, free the memory block pointed to by ptr. * @param ptr Pointer to a pointer to a memory block already allocated * with av_realloc(), or pointer to a pointer to NULL. * The pointer is updated on success, or freed on failure. * @param size Size in bytes for the memory block to be allocated or * reallocated * @return Zero on success, an AVERROR error code on failure. * @warning Pointers originating from the av_malloc() family of functions must * not be passed to av_reallocp(). The former can be implemented using * memalign() (or other functions), and there is no guarantee that * pointers from such functions can be passed to realloc() at all. * The situation is undefined according to POSIX and may crash with * some libc implementations. */ int av_reallocp(void *ptr, size_t size); /** * Allocate or reallocate an array. * If ptr is NULL and nmemb > 0, allocate a new block. If * nmemb is zero, free the memory block pointed to by ptr. * @param ptr Pointer to a memory block already allocated with * av_realloc() or NULL. * @param nmemb Number of elements * @param size Size of the single element * @return Pointer to a newly-reallocated block or NULL if the block * cannot be reallocated or the function is used to free the memory block. * @warning Pointers originating from the av_malloc() family of functions must * not be passed to av_realloc(). The former can be implemented using * memalign() (or other functions), and there is no guarantee that * pointers from such functions can be passed to realloc() at all. * The situation is undefined according to POSIX and may crash with * some libc implementations. */ av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size); /** * Allocate or reallocate an array through a pointer to a pointer. * If *ptr is NULL and nmemb > 0, allocate a new block. If * nmemb is zero, free the memory block pointed to by ptr. * @param ptr Pointer to a pointer to a memory block already allocated * with av_realloc(), or pointer to a pointer to NULL. * The pointer is updated on success, or freed on failure. * @param nmemb Number of elements * @param size Size of the single element * @return Zero on success, an AVERROR error code on failure. * @warning Pointers originating from the av_malloc() family of functions must * not be passed to av_realloc(). The former can be implemented using * memalign() (or other functions), and there is no guarantee that * pointers from such functions can be passed to realloc() at all. * The situation is undefined according to POSIX and may crash with * some libc implementations. */ av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size); /** * Free a memory block which has been allocated with av_malloc(z)() or * av_realloc(). * @param ptr Pointer to the memory block which should be freed. * @note ptr = NULL is explicitly allowed. * @note It is recommended that you use av_freep() instead. * @see av_freep() */ void av_free(void *ptr); /** * Allocate a block of size bytes with alignment suitable for all * memory accesses (including vectors if available on the CPU) and * zero all the bytes of the block. * @param size Size in bytes for the memory block to be allocated. * @return Pointer to the allocated block, NULL if it cannot be allocated. * @see av_malloc() */ void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1); /** * Allocate a block of size * nmemb bytes with av_mallocz(). * @param nmemb Number of elements * @param size Size of the single element * @return Pointer to the allocated block, NULL if the block cannot * be allocated. * @see av_mallocz() * @see av_malloc_array() */ av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size) { if (!size || nmemb >= INT_MAX / size) return NULL; return av_mallocz(nmemb * size); } /** * Duplicate the string s. * @param s string to be duplicated * @return Pointer to a newly-allocated string containing a * copy of s or NULL if the string cannot be allocated. */ char *av_strdup(const char *s) av_malloc_attrib; /** * Duplicate a substring of the string s. * @param s string to be duplicated * @param len the maximum length of the resulting string (not counting the * terminating byte). * @return Pointer to a newly-allocated string containing a * copy of s or NULL if the string cannot be allocated. */ char *av_strndup(const char *s, size_t len) av_malloc_attrib; /** * Free a memory block which has been allocated with av_malloc(z)() or * av_realloc() and set the pointer pointing to it to NULL. * @param ptr Pointer to the pointer to the memory block which should * be freed. * @see av_free() */ void av_freep(void *ptr); /** * deliberately overlapping memcpy implementation * @param dst destination buffer * @param back how many bytes back we start (the initial size of the overlapping window) * @param cnt number of bytes to copy, must be >= 0 * * cnt > back is valid, this will copy the bytes we just copied, * thus creating a repeating pattern with a period length of back. */ void av_memcpy_backptr(uint8_t *dst, int back, int cnt); /** * Reallocate the given block if it is not large enough, otherwise do nothing. * * @see av_realloc */ void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size); /** * Allocate a buffer, reusing the given one if large enough. * * Contrary to av_fast_realloc the current buffer contents might not be * preserved and on error the old buffer is freed, thus no special * handling to avoid memleaks is necessary. * * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer * @param size size of the buffer *ptr points to * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and * *size 0 if an error occurred. */ void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size); /** * @} */ #endif /* AVUTIL_MEM_H */