/* * default memory allocator for libavutil * Copyright (c) 2002 Fabrice Bellard * * This file is part of FFmpeg. * * FFmpeg 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, * 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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * default memory allocator for libavutil */ #define _XOPEN_SOURCE 600 #include "config.h" #include #include #include #include #if HAVE_MALLOC_H #include #endif #include "avutil.h" #include "intreadwrite.h" #include "mem.h" /* here we can use OS-dependent allocation functions */ #undef free #undef malloc #undef realloc #ifdef MALLOC_PREFIX #define malloc AV_JOIN(MALLOC_PREFIX, malloc) #define memalign AV_JOIN(MALLOC_PREFIX, memalign) #define posix_memalign AV_JOIN(MALLOC_PREFIX, posix_memalign) #define realloc AV_JOIN(MALLOC_PREFIX, realloc) #define free AV_JOIN(MALLOC_PREFIX, free) void *malloc(size_t size); void *memalign(size_t align, size_t size); int posix_memalign(void **ptr, size_t align, size_t size); void *realloc(void *ptr, size_t size); void free(void *ptr); #endif /* MALLOC_PREFIX */ #define ALIGN (HAVE_AVX ? 32 : 16) /* NOTE: if you want to override these functions with your own * implementations (not recommended) you have to link libav* as * dynamic libraries and remove -Wl,-Bsymbolic from the linker flags. * Note that this will cost performance. */ static size_t max_alloc_size= INT_MAX; void av_max_alloc(size_t max){ max_alloc_size = max; } void *av_malloc(size_t size) { void *ptr = NULL; #if CONFIG_MEMALIGN_HACK long diff; #endif /* let's disallow possible ambiguous cases */ if (size > (max_alloc_size - 32)) return NULL; #if CONFIG_MEMALIGN_HACK ptr = malloc(size + ALIGN); if (!ptr) return ptr; diff = ((-(long)ptr - 1)&(ALIGN - 1)) + 1; ptr = (char *)ptr + diff; ((char *)ptr)[-1] = diff; #elif HAVE_POSIX_MEMALIGN if (size) //OS X on SDK 10.6 has a broken posix_memalign implementation if (posix_memalign(&ptr, ALIGN, size)) ptr = NULL; #elif HAVE_ALIGNED_MALLOC ptr = _aligned_malloc(size, ALIGN); #elif HAVE_MEMALIGN ptr = memalign(ALIGN, size); /* Why 64? * Indeed, we should align it: * on 4 for 386 * on 16 for 486 * on 32 for 586, PPro - K6-III * on 64 for K7 (maybe for P3 too). * Because L1 and L2 caches are aligned on those values. * But I don't want to code such logic here! */ /* Why 32? * For AVX ASM. SSE / NEON needs only 16. * Why not larger? Because I did not see a difference in benchmarks ... */ /* benchmarks with P3 * memalign(64) + 1 3071, 3051, 3032 * memalign(64) + 2 3051, 3032, 3041 * memalign(64) + 4 2911, 2896, 2915 * memalign(64) + 8 2545, 2554, 2550 * memalign(64) + 16 2543, 2572, 2563 * memalign(64) + 32 2546, 2545, 2571 * memalign(64) + 64 2570, 2533, 2558 * * BTW, malloc seems to do 8-byte alignment by default here. */ #else ptr = malloc(size); #endif if(!ptr && !size) { size = 1; ptr= av_malloc(1); } #if CONFIG_MEMORY_POISONING if (ptr) memset(ptr, 0x2a, size); #endif return ptr; } void *av_realloc(void *ptr, size_t size) { #if CONFIG_MEMALIGN_HACK int diff; #endif /* let's disallow possible ambiguous cases */ if (size > (max_alloc_size - 32)) return NULL; #if CONFIG_MEMALIGN_HACK //FIXME this isn't aligned correctly, though it probably isn't needed if (!ptr) return av_malloc(size); diff = ((char *)ptr)[-1]; ptr = realloc((char *)ptr - diff, size + diff); if (ptr) ptr = (char *)ptr + diff; return ptr; #elif HAVE_ALIGNED_MALLOC return _aligned_realloc(ptr, size + !size, ALIGN); #else return realloc(ptr, size + !size); #endif } void *av_realloc_f(void *ptr, size_t nelem, size_t elsize) { size_t size; void *r; if (av_size_mult(elsize, nelem, &size)) { av_free(ptr); return NULL; } r = av_realloc(ptr, size); if (!r && size) av_free(ptr); return r; } void av_free(void *ptr) { #if CONFIG_MEMALIGN_HACK if (ptr) free((char *)ptr - ((char *)ptr)[-1]); #elif HAVE_ALIGNED_MALLOC _aligned_free(ptr); #else free(ptr); #endif } void av_freep(void *arg) { void **ptr = (void **)arg; av_free(*ptr); *ptr = NULL; } void *av_mallocz(size_t size) { void *ptr = av_malloc(size); if (ptr) memset(ptr, 0, size); return ptr; } void *av_calloc(size_t nmemb, size_t size) { if (size <= 0 || nmemb >= INT_MAX / size) return NULL; return av_mallocz(nmemb * size); } char *av_strdup(const char *s) { char *ptr = NULL; if (s) { int len = strlen(s) + 1; ptr = av_malloc(len); if (ptr) memcpy(ptr, s, len); } return ptr; } /* add one element to a dynamic array */ void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem) { /* see similar ffmpeg.c:grow_array() */ int nb, nb_alloc; intptr_t *tab; nb = *nb_ptr; tab = *(intptr_t**)tab_ptr; if ((nb & (nb - 1)) == 0) { if (nb == 0) nb_alloc = 1; else nb_alloc = nb * 2; tab = av_realloc(tab, nb_alloc * sizeof(intptr_t)); *(intptr_t**)tab_ptr = tab; } tab[nb++] = (intptr_t)elem; *nb_ptr = nb; } void av_memcpy_backptr(uint8_t *dst, int back, int cnt) { const uint8_t *src = &dst[-back]; if (back <= 1) { memset(dst, *src, cnt); } else { if (cnt >= 4) { AV_COPY16U(dst, src); AV_COPY16U(dst + 2, src + 2); src += 4; dst += 4; cnt -= 4; } if (cnt >= 8) { AV_COPY16U(dst, src); AV_COPY16U(dst + 2, src + 2); AV_COPY16U(dst + 4, src + 4); AV_COPY16U(dst + 6, src + 6); src += 8; dst += 8; cnt -= 8; } if (cnt > 0) { int blocklen = back; while (cnt > blocklen) { memcpy(dst, src, blocklen); dst += blocklen; cnt -= blocklen; blocklen <<= 1; } memcpy(dst, src, cnt); } } }