/* * default memory allocator for libavutil * Copyright (c) 2002 Fabrice Bellard * * 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 * default memory allocator for libavutil */ #include "config.h" #include <limits.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #if HAVE_MALLOC_H #include <malloc.h> #endif #include "avutil.h" #include "common.h" #include "intreadwrite.h" #include "mem.h" #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 */ /* You can redefine av_malloc and av_free in your project to use your * memory allocator. You do not need to suppress this file because the * linker will do it automatically. */ void *av_malloc(size_t size) { void *ptr = NULL; #if CONFIG_MEMALIGN_HACK long diff; #endif /* let's disallow possibly ambiguous cases */ if (size > (INT_MAX - 32) || !size) return NULL; #if CONFIG_MEMALIGN_HACK ptr = malloc(size + 32); if (!ptr) return ptr; diff = ((-(long)ptr - 1) & 31) + 1; ptr = (char *)ptr + diff; ((char *)ptr)[-1] = diff; #elif HAVE_POSIX_MEMALIGN if (posix_memalign(&ptr, 32, size)) ptr = NULL; #elif HAVE_ALIGNED_MALLOC ptr = _aligned_malloc(size, 32); #elif HAVE_MEMALIGN ptr = memalign(32, 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 return ptr; } void *av_realloc(void *ptr, size_t size) { #if CONFIG_MEMALIGN_HACK int diff; #endif /* let's disallow possibly ambiguous cases */ if (size > (INT_MAX - 16)) 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]; return (char *)realloc((char *)ptr - diff, size + diff) + diff; #elif HAVE_ALIGNED_MALLOC return _aligned_realloc(ptr, size, 32); #else return realloc(ptr, size); #endif } int av_reallocp(void *ptr, size_t size) { void **ptrptr = ptr; void *ret; if (!size) { av_freep(ptr); return 0; } ret = av_realloc(*ptrptr, size); if (!ret) { av_freep(ptr); return AVERROR(ENOMEM); } *ptrptr = ret; return 0; } void *av_realloc_array(void *ptr, size_t nmemb, size_t size) { if (!size || nmemb >= INT_MAX / size) return NULL; return av_realloc(ptr, nmemb * size); } int av_reallocp_array(void *ptr, size_t nmemb, size_t size) { void **ptrptr = ptr; void *ret; if (!size || nmemb >= INT_MAX / size) return AVERROR(ENOMEM); if (!nmemb) { av_freep(ptr); return 0; } ret = av_realloc(*ptrptr, nmemb * size); if (!ret) { av_freep(ptr); return AVERROR(ENOMEM); } *ptrptr = ret; return 0; } 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; } char *av_strdup(const char *s) { char *ptr = NULL; if (s) { int len = strlen(s) + 1; ptr = av_realloc(NULL, len); if (ptr) memcpy(ptr, s, len); } return ptr; } char *av_strndup(const char *s, size_t len) { char *ret = NULL, *end; if (!s) return NULL; end = memchr(s, 0, len); if (end) len = end - s; ret = av_realloc(NULL, len + 1); if (!ret) return NULL; memcpy(ret, s, len); ret[len] = 0; return ret; } static void fill16(uint8_t *dst, int len) { uint32_t v = AV_RN16(dst - 2); v |= v << 16; while (len >= 4) { AV_WN32(dst, v); dst += 4; len -= 4; } while (len--) { *dst = dst[-2]; dst++; } } static void fill24(uint8_t *dst, int len) { #if HAVE_BIGENDIAN uint32_t v = AV_RB24(dst - 3); uint32_t a = v << 8 | v >> 16; uint32_t b = v << 16 | v >> 8; uint32_t c = v << 24 | v; #else uint32_t v = AV_RL24(dst - 3); uint32_t a = v | v << 24; uint32_t b = v >> 8 | v << 16; uint32_t c = v >> 16 | v << 8; #endif while (len >= 12) { AV_WN32(dst, a); AV_WN32(dst + 4, b); AV_WN32(dst + 8, c); dst += 12; len -= 12; } if (len >= 4) { AV_WN32(dst, a); dst += 4; len -= 4; } if (len >= 4) { AV_WN32(dst, b); dst += 4; len -= 4; } while (len--) { *dst = dst[-3]; dst++; } } static void fill32(uint8_t *dst, int len) { uint32_t v = AV_RN32(dst - 4); while (len >= 4) { AV_WN32(dst, v); dst += 4; len -= 4; } while (len--) { *dst = dst[-4]; dst++; } } void av_memcpy_backptr(uint8_t *dst, int back, int cnt) { const uint8_t *src = &dst[-back]; if (!back) return; if (back == 1) { memset(dst, *src, cnt); } else if (back == 2) { fill16(dst, cnt); } else if (back == 3) { fill24(dst, cnt); } else if (back == 4) { fill32(dst, cnt); } else { if (cnt >= 16) { int blocklen = back; while (cnt > blocklen) { memcpy(dst, src, blocklen); dst += blocklen; cnt -= blocklen; blocklen <<= 1; } memcpy(dst, src, cnt); return; } if (cnt >= 8) { AV_COPY32U(dst, src); AV_COPY32U(dst + 4, src + 4); src += 8; dst += 8; cnt -= 8; } if (cnt >= 4) { AV_COPY32U(dst, src); src += 4; dst += 4; cnt -= 4; } if (cnt >= 2) { AV_COPY16U(dst, src); src += 2; dst += 2; cnt -= 2; } if (cnt) *dst = *src; } } void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size) { if (min_size < *size) return ptr; min_size = FFMAX(17 * min_size / 16 + 32, min_size); ptr = av_realloc(ptr, min_size); /* we could set this to the unmodified min_size but this is safer * if the user lost the ptr and uses NULL now */ if (!ptr) min_size = 0; *size = min_size; return ptr; } void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size) { void **p = ptr; if (min_size < *size) return; min_size = FFMAX(17 * min_size / 16 + 32, min_size); av_free(*p); *p = av_malloc(min_size); if (!*p) min_size = 0; *size = min_size; }