1/* 2 * Copyright (C) 2011 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include "config.h" 27#include "ConservativeRoots.h" 28 29#include "CodeBlock.h" 30#include "CopiedSpace.h" 31#include "CopiedSpaceInlines.h" 32#include "DFGCodeBlocks.h" 33#include "JSCell.h" 34#include "JSObject.h" 35#include "Structure.h" 36 37namespace JSC { 38 39ConservativeRoots::ConservativeRoots(const MarkedBlockSet* blocks, CopiedSpace* copiedSpace) 40 : m_roots(m_inlineRoots) 41 , m_size(0) 42 , m_capacity(inlineCapacity) 43 , m_blocks(blocks) 44 , m_copiedSpace(copiedSpace) 45{ 46} 47 48ConservativeRoots::~ConservativeRoots() 49{ 50 if (m_roots != m_inlineRoots) 51 OSAllocator::decommitAndRelease(m_roots, m_capacity * sizeof(JSCell*)); 52} 53 54void ConservativeRoots::grow() 55{ 56 size_t newCapacity = m_capacity == inlineCapacity ? nonInlineCapacity : m_capacity * 2; 57 JSCell** newRoots = static_cast<JSCell**>(OSAllocator::reserveAndCommit(newCapacity * sizeof(JSCell*))); 58 memcpy(newRoots, m_roots, m_size * sizeof(JSCell*)); 59 if (m_roots != m_inlineRoots) 60 OSAllocator::decommitAndRelease(m_roots, m_capacity * sizeof(JSCell*)); 61 m_capacity = newCapacity; 62 m_roots = newRoots; 63} 64 65template<typename MarkHook> 66inline void ConservativeRoots::genericAddPointer(void* p, TinyBloomFilter filter, MarkHook& markHook) 67{ 68 markHook.mark(p); 69 70 m_copiedSpace->pinIfNecessary(p); 71 72 MarkedBlock* candidate = MarkedBlock::blockFor(p); 73 if (filter.ruleOut(reinterpret_cast<Bits>(candidate))) { 74 ASSERT(!candidate || !m_blocks->set().contains(candidate)); 75 return; 76 } 77 78 if (!MarkedBlock::isAtomAligned(p)) 79 return; 80 81 if (!m_blocks->set().contains(candidate)) 82 return; 83 84 if (!candidate->isLiveCell(p)) 85 return; 86 87 if (m_size == m_capacity) 88 grow(); 89 90 m_roots[m_size++] = static_cast<JSCell*>(p); 91} 92 93template<typename MarkHook> 94void ConservativeRoots::genericAddSpan(void* begin, void* end, MarkHook& markHook) 95{ 96 ASSERT(begin <= end); 97 ASSERT((static_cast<char*>(end) - static_cast<char*>(begin)) < 0x1000000); 98 ASSERT(isPointerAligned(begin)); 99 ASSERT(isPointerAligned(end)); 100 101 TinyBloomFilter filter = m_blocks->filter(); // Make a local copy of filter to show the compiler it won't alias, and can be register-allocated. 102 for (char** it = static_cast<char**>(begin); it != static_cast<char**>(end); ++it) 103 genericAddPointer(*it, filter, markHook); 104} 105 106class DummyMarkHook { 107public: 108 void mark(void*) { } 109}; 110 111void ConservativeRoots::add(void* begin, void* end) 112{ 113 DummyMarkHook dummy; 114 genericAddSpan(begin, end, dummy); 115} 116 117void ConservativeRoots::add(void* begin, void* end, JITStubRoutineSet& jitStubRoutines) 118{ 119 genericAddSpan(begin, end, jitStubRoutines); 120} 121 122template<typename T, typename U> 123class CompositeMarkHook { 124public: 125 CompositeMarkHook(T& first, U& second) 126 : m_first(first) 127 , m_second(second) 128 { 129 } 130 131 void mark(void* address) 132 { 133 m_first.mark(address); 134 m_second.mark(address); 135 } 136 137private: 138 T& m_first; 139 U& m_second; 140}; 141 142void ConservativeRoots::add( 143 void* begin, void* end, JITStubRoutineSet& jitStubRoutines, DFGCodeBlocks& dfgCodeBlocks) 144{ 145 CompositeMarkHook<JITStubRoutineSet, DFGCodeBlocks> markHook( 146 jitStubRoutines, dfgCodeBlocks); 147 genericAddSpan(begin, end, markHook); 148} 149 150} // namespace JSC 151