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| 1 /* | |
| 2 * Copyright (C) 1998-2000 Netscape Communications Corporation. | |
| 3 * Copyright (C) 2003-6 Apple Computer | |
| 4 * | |
| 5 * Other contributors: | |
| 6 * Nick Blievers <nickb@adacel.com.au> | |
| 7 * Jeff Hostetler <jeff@nerdone.com> | |
| 8 * Tom Rini <trini@kernel.crashing.org> | |
| 9 * Raffaele Sena <raff@netwinder.org> | |
| 10 * | |
| 11 * This library is free software; you can redistribute it and/or | |
| 12 * modify it under the terms of the GNU Lesser General Public | |
| 13 * License as published by the Free Software Foundation; either | |
| 14 * version 2.1 of the License, or (at your option) any later version. | |
| 15 * | |
| 16 * This library is distributed in the hope that it will be useful, | |
| 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 19 * Lesser General Public License for more details. | |
| 20 * | |
| 21 * You should have received a copy of the GNU Lesser General Public | |
| 22 * License along with this library; if not, write to the Free Software | |
| 23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 US
A | |
| 24 * | |
| 25 * Alternatively, the contents of this file may be used under the terms | |
| 26 * of either the Mozilla Public License Version 1.1, found at | |
| 27 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public | |
| 28 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html | |
| 29 * (the "GPL"), in which case the provisions of the MPL or the GPL are | |
| 30 * applicable instead of those above. If you wish to allow use of your | |
| 31 * version of this file only under the terms of one of those two | |
| 32 * licenses (the MPL or the GPL) and not to allow others to use your | |
| 33 * version of this file under the LGPL, indicate your decision by | |
| 34 * deletingthe provisions above and replace them with the notice and | |
| 35 * other provisions required by the MPL or the GPL, as the case may be. | |
| 36 * If you do not delete the provisions above, a recipient may use your | |
| 37 * version of this file under any of the LGPL, the MPL or the GPL. | |
| 38 */ | |
| 39 | |
| 40 /* | |
| 41 * Lifetime-based fast allocation, inspired by much prior art, including | |
| 42 * "Fast Allocation and Deallocation of Memory Based on Object Lifetimes" | |
| 43 * David R. Hanson, Software -- Practice and Experience, Vol. 20(1). | |
| 44 */ | |
| 45 | |
| 46 #include "config.h" | |
| 47 #include "core/platform/Arena.h" | |
| 48 | |
| 49 #include <stdlib.h> | |
| 50 #include <string.h> | |
| 51 #include <algorithm> | |
| 52 #include <wtf/Assertions.h> | |
| 53 #include <wtf/FastMalloc.h> | |
| 54 | |
| 55 using namespace std; | |
| 56 | |
| 57 namespace WebCore { | |
| 58 | |
| 59 #ifdef DEBUG_ARENA_MALLOC | |
| 60 static int i = 0; | |
| 61 #endif | |
| 62 | |
| 63 #define ARENA_DEFAULT_ALIGN sizeof(double) | |
| 64 #define BIT(n) ((unsigned int)1 << (n)) | |
| 65 #define BITMASK(n) (BIT(n) - 1) | |
| 66 #define CEILING_LOG2(_log2, _n) \ | |
| 67 unsigned int j_ = (unsigned int)(_n); \ | |
| 68 (_log2) = 0; \ | |
| 69 if ((j_) & ((j_)-1)) \ | |
| 70 (_log2) += 1; \ | |
| 71 if ((j_) >> 16) \ | |
| 72 (_log2) += 16, (j_) >>= 16; \ | |
| 73 if ((j_) >> 8) \ | |
| 74 (_log2) += 8, (j_) >>= 8; \ | |
| 75 if ((j_) >> 4) \ | |
| 76 (_log2) += 4, (j_) >>= 4; \ | |
| 77 if ((j_) >> 2) \ | |
| 78 (_log2) += 2, (j_) >>= 2; \ | |
| 79 if ((j_) >> 1) \ | |
| 80 (_log2) += 1; | |
| 81 #define FREE_PATTERN 0xDA | |
| 82 | |
| 83 static int CeilingLog2(unsigned int i) { | |
| 84 int log2; | |
| 85 CEILING_LOG2(log2, i); | |
| 86 return log2; | |
| 87 } | |
| 88 | |
| 89 void InitArenaPool(ArenaPool* pool, const char*, unsigned size, unsigned align) | |
| 90 { | |
| 91 if (align == 0) | |
| 92 align = ARENA_DEFAULT_ALIGN; | |
| 93 pool->mask = BITMASK(CeilingLog2(align)); | |
| 94 pool->first.next = NULL; | |
| 95 pool->first.base = pool->first.avail = pool->first.limit = (uword)ARENA_ALI
GN(&pool->first + 1); | |
| 96 pool->current = &pool->first; | |
| 97 pool->arenasize = size; | |
| 98 } | |
| 99 | |
| 100 void* ArenaAllocate(ArenaPool* pool, unsigned int numBytes, unsigned int& bytesA
llocated) | |
| 101 { | |
| 102 Arena* arena; | |
| 103 char* returnPointer; | |
| 104 | |
| 105 ASSERT((numBytes & pool->mask) == 0); | |
| 106 | |
| 107 numBytes = (uword)ARENA_ALIGN(numBytes); | |
| 108 | |
| 109 // attempt to allocate from arenas at pool->current | |
| 110 { | |
| 111 arena = pool->current; | |
| 112 do { | |
| 113 if (arena->avail + numBytes <= arena->limit) { | |
| 114 pool->current = arena; | |
| 115 returnPointer = (char *)arena->avail; | |
| 116 arena->avail += numBytes; | |
| 117 return returnPointer; | |
| 118 } | |
| 119 } while (NULL != (arena = arena->next)); | |
| 120 } | |
| 121 | |
| 122 // attempt to allocate from the heap | |
| 123 { | |
| 124 unsigned int size = max(pool->arenasize, numBytes); | |
| 125 size += sizeof *arena + pool->mask; /* header and alignment slop */ | |
| 126 #ifdef DEBUG_ARENA_MALLOC | |
| 127 i++; | |
| 128 printf("Malloc: %d\n", i); | |
| 129 #endif | |
| 130 bytesAllocated = size; | |
| 131 arena = (Arena*)fastMalloc(size); | |
| 132 // fastMalloc will abort() if it fails, so we are guaranteed that a is n
ot 0. | |
| 133 arena->limit = (uword)arena + size; | |
| 134 arena->base = arena->avail = (uword)ARENA_ALIGN(arena + 1); | |
| 135 returnPointer = (char *)arena->avail; | |
| 136 arena->avail += numBytes; | |
| 137 // the newly allocated arena is linked after pool->current and becomes p
ool->current. | |
| 138 arena->next = pool->current->next; | |
| 139 pool->current->next = arena; | |
| 140 pool->current = arena; | |
| 141 if (!pool->first.next) | |
| 142 pool->first.next = arena; | |
| 143 return(returnPointer); | |
| 144 } | |
| 145 } | |
| 146 | |
| 147 // Free tail arenas linked after head, which may not be the true list head. | |
| 148 // Reset pool->current to point to head in case it pointed at a tail arena. | |
| 149 static void FreeArenaList(ArenaPool* pool, Arena* head) | |
| 150 { | |
| 151 Arena** arenaPointer = &head->next; | |
| 152 Arena* arena = *arenaPointer; | |
| 153 if (!arena) | |
| 154 return; | |
| 155 | |
| 156 #ifdef DEBUG | |
| 157 do { | |
| 158 ASSERT(arena->base <= arena->avail && arena->avail <= arena->limit); | |
| 159 arena->avail = arena->base; | |
| 160 memset((void*)(arena)->avail, FREE_PATTERN, (arena)->limit - (arena)->av
ail) | |
| 161 } while ((arena = arena->next) != 0); | |
| 162 arena = *arenaPointer; | |
| 163 #endif | |
| 164 | |
| 165 do { | |
| 166 *arenaPointer = arena->next; | |
| 167 | |
| 168 #ifdef DEBUG | |
| 169 memset((void*)(arena), FREE_PATTERN, (arena)->limit - (uword)(arena)); | |
| 170 #endif | |
| 171 | |
| 172 #ifdef DEBUG_ARENA_MALLOC | |
| 173 i--; | |
| 174 printf("Free: %d\n", i); | |
| 175 #endif | |
| 176 | |
| 177 fastFree(arena); | |
| 178 arena = 0; | |
| 179 } while ((arena = *arenaPointer) != 0); | |
| 180 pool->current = head; | |
| 181 } | |
| 182 | |
| 183 void FinishArenaPool(ArenaPool* pool) | |
| 184 { | |
| 185 FreeArenaList(pool, &pool->first); | |
| 186 } | |
| 187 | |
| 188 } | |
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Chromium Code Reviews
Issue 16896019:
Replace RenderArena with PartitionAlloc. (Closed)
Base URL: svn://svn.chromium.org/blink/trunk