1 /* 2 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved. 3 * Copyright (C) 2007 Eric Seidel <eric (at) webkit.org> 4 * 5 * This library is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU Lesser General Public 7 * License as published by the Free Software Foundation; either 8 * version 2 of the License, or (at your option) any later version. 9 * 10 * This library is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * Lesser General Public License for more details. 14 * 15 * You should have received a copy of the GNU Lesser General Public 16 * License along with this library; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 18 * 19 */ 20 21 #include "config.h" 22 #include "MarkedSpace.h" 23 24 #include "JSCell.h" 25 #include "JSGlobalData.h" 26 #include "JSLock.h" 27 #include "JSObject.h" 28 #include "ScopeChain.h" 29 30 namespace JSC { 31 32 class Structure; 33 34 MarkedSpace::MarkedSpace(JSGlobalData* globalData) 35 : m_waterMark(0) 36 , m_highWaterMark(0) 37 , m_globalData(globalData) 38 { 39 for (size_t cellSize = preciseStep; cellSize < preciseCutoff; cellSize += preciseStep) 40 sizeClassFor(cellSize).cellSize = cellSize; 41 42 for (size_t cellSize = impreciseStep; cellSize < impreciseCutoff; cellSize += impreciseStep) 43 sizeClassFor(cellSize).cellSize = cellSize; 44 } 45 46 void MarkedSpace::destroy() 47 { 48 clearMarks(); 49 shrink(); 50 ASSERT(!size()); 51 } 52 53 MarkedBlock* MarkedSpace::allocateBlock(SizeClass& sizeClass) 54 { 55 MarkedBlock* block = MarkedBlock::create(globalData(), sizeClass.cellSize); 56 sizeClass.blockList.append(block); 57 sizeClass.nextBlock = block; 58 m_blocks.add(block); 59 60 return block; 61 } 62 63 void MarkedSpace::freeBlocks(DoublyLinkedList<MarkedBlock>& blocks) 64 { 65 MarkedBlock* next; 66 for (MarkedBlock* block = blocks.head(); block; block = next) { 67 next = block->next(); 68 69 blocks.remove(block); 70 m_blocks.remove(block); 71 MarkedBlock::destroy(block); 72 } 73 } 74 75 void* MarkedSpace::allocateFromSizeClass(SizeClass& sizeClass) 76 { 77 for (MarkedBlock*& block = sizeClass.nextBlock ; block; block = block->next()) { 78 if (void* result = block->allocate()) 79 return result; 80 81 m_waterMark += block->capacity(); 82 } 83 84 if (m_waterMark < m_highWaterMark) 85 return allocateBlock(sizeClass)->allocate(); 86 87 return 0; 88 } 89 90 void MarkedSpace::shrink() 91 { 92 // We record a temporary list of empties to avoid modifying m_blocks while iterating it. 93 DoublyLinkedList<MarkedBlock> empties; 94 95 BlockIterator end = m_blocks.end(); 96 for (BlockIterator it = m_blocks.begin(); it != end; ++it) { 97 MarkedBlock* block = *it; 98 if (block->isEmpty()) { 99 SizeClass& sizeClass = sizeClassFor(block->cellSize()); 100 sizeClass.blockList.remove(block); 101 sizeClass.nextBlock = sizeClass.blockList.head(); 102 empties.append(block); 103 } 104 } 105 106 freeBlocks(empties); 107 ASSERT(empties.isEmpty()); 108 } 109 110 void MarkedSpace::clearMarks() 111 { 112 BlockIterator end = m_blocks.end(); 113 for (BlockIterator it = m_blocks.begin(); it != end; ++it) 114 (*it)->clearMarks(); 115 } 116 117 void MarkedSpace::sweep() 118 { 119 BlockIterator end = m_blocks.end(); 120 for (BlockIterator it = m_blocks.begin(); it != end; ++it) 121 (*it)->sweep(); 122 } 123 124 size_t MarkedSpace::objectCount() const 125 { 126 size_t result = 0; 127 BlockIterator end = m_blocks.end(); 128 for (BlockIterator it = m_blocks.begin(); it != end; ++it) 129 result += (*it)->markCount(); 130 return result; 131 } 132 133 size_t MarkedSpace::size() const 134 { 135 size_t result = 0; 136 BlockIterator end = m_blocks.end(); 137 for (BlockIterator it = m_blocks.begin(); it != end; ++it) 138 result += (*it)->size(); 139 return result; 140 } 141 142 size_t MarkedSpace::capacity() const 143 { 144 size_t result = 0; 145 BlockIterator end = m_blocks.end(); 146 for (BlockIterator it = m_blocks.begin(); it != end; ++it) 147 result += (*it)->capacity(); 148 return result; 149 } 150 151 void MarkedSpace::reset() 152 { 153 m_waterMark = 0; 154 155 for (size_t cellSize = preciseStep; cellSize < preciseCutoff; cellSize += preciseStep) 156 sizeClassFor(cellSize).reset(); 157 158 for (size_t cellSize = impreciseStep; cellSize < impreciseCutoff; cellSize += impreciseStep) 159 sizeClassFor(cellSize).reset(); 160 161 BlockIterator end = m_blocks.end(); 162 for (BlockIterator it = m_blocks.begin(); it != end; ++it) 163 (*it)->reset(); 164 } 165 166 } // namespace JSC 167
