X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Fmem.h;h=f3cf56c498f45f24f334a1ba9d80847fdc0314ea;hb=acfa7a2178f08fd81b66279959cd55ec3ae237e2;hp=fe18561e0e1597823a98ba7a6c0f8a7b4efef06c;hpb=06be9d9d8ed79d043ffaa816185e69e9f19e005e;p=ffmpeg diff --git a/libavutil/mem.h b/libavutil/mem.h index fe18561e0e1..f3cf56c498f 100644 --- a/libavutil/mem.h +++ b/libavutil/mem.h @@ -1,32 +1,63 @@ /* * copyright (c) 2006 Michael Niedermayer * - * This file is part of FFmpeg. + * This file is part of Libav. * - * FFmpeg is free software; you can redistribute it and/or + * 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. * - * FFmpeg is distributed in the hope that it will be useful, + * 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 FFmpeg; if not, write to the Free Software + * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** - * @file libavutil/mem.h + * @file * memory handling functions */ #ifndef AVUTIL_MEM_H #define AVUTIL_MEM_H -#include "common.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__) || defined(__clang__) + #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__)) @@ -34,38 +65,116 @@ #define av_malloc_attrib #endif -#if (!defined(__ICC) || __ICC > 1110) && AV_GCC_VERSION_AT_LEAST(4,3) - #define av_alloc_size(n) __attribute__((alloc_size(n))) +#if AV_GCC_VERSION_AT_LEAST(4,3) + #define av_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__))) #else - #define av_alloc_size(n) + #define av_alloc_size(...) #endif /** - * Allocates a block of size bytes with alignment suitable for all + * 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(unsigned int size) av_malloc_attrib av_alloc_size(1); +void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1); /** - * Allocates or reallocates a block of memory. - * If ptr is NULL and size > 0, allocates a new block. If \p - * size is zero, frees the memory block pointed to by ptr. - * @param size Size in bytes for the memory block to be allocated or - * reallocated. + * 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_malloc(z)() or av_realloc() or NULL. - * @return Pointer to a newly reallocated block or NULL if the block + * 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, unsigned int size) av_alloc_size(2); +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); /** - * Frees a memory block which has been allocated with av_malloc(z)() or + * 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. @@ -75,25 +184,51 @@ void *av_realloc(void *ptr, unsigned int size) av_alloc_size(2); void av_free(void *ptr); /** - * Allocates a block of size bytes with alignment suitable for all + * Allocate a block of size bytes with alignment suitable for all * memory accesses (including vectors if available on the CPU) and - * zeroes all the bytes of the block. + * 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(unsigned int size) av_malloc_attrib av_alloc_size(1); +void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1); /** - * Duplicates the string s. + * 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 + * @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; /** - * Frees a memory block which has been allocated with av_malloc(z)() or + * 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. @@ -101,4 +236,40 @@ char *av_strdup(const char *s) av_malloc_attrib; */ 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 */