1/* 2 * Copyright (C) 2009, 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. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#ifndef MarkStack_h 27#define MarkStack_h 28 29#if ENABLE(OBJECT_MARK_LOGGING) 30#define MARK_LOG_MESSAGE0(message) dataLogF(message) 31#define MARK_LOG_MESSAGE1(message, arg1) dataLogF(message, arg1) 32#define MARK_LOG_MESSAGE2(message, arg1, arg2) dataLogF(message, arg1, arg2) 33#define MARK_LOG_ROOT(visitor, rootName) \ 34 dataLogF("\n%s: ", rootName); \ 35 (visitor).resetChildCount() 36#define MARK_LOG_PARENT(visitor, parent) \ 37 dataLogF("\n%p (%s): ", parent, parent->className() ? parent->className() : "unknown"); \ 38 (visitor).resetChildCount() 39#define MARK_LOG_CHILD(visitor, child) \ 40 if ((visitor).childCount()) \ 41 dataLogFString(", "); \ 42 dataLogF("%p", child); \ 43 (visitor).incrementChildCount() 44#else 45#define MARK_LOG_MESSAGE0(message) do { } while (false) 46#define MARK_LOG_MESSAGE1(message, arg1) do { } while (false) 47#define MARK_LOG_MESSAGE2(message, arg1, arg2) do { } while (false) 48#define MARK_LOG_ROOT(visitor, rootName) do { } while (false) 49#define MARK_LOG_PARENT(visitor, parent) do { } while (false) 50#define MARK_LOG_CHILD(visitor, child) do { } while (false) 51#endif 52 53#include "HeapBlock.h" 54#include <wtf/StdLibExtras.h> 55 56namespace JSC { 57 58class BlockAllocator; 59class DeadBlock; 60class JSCell; 61 62class MarkStackSegment : public HeapBlock<MarkStackSegment> { 63public: 64 MarkStackSegment(Region* region) 65 : HeapBlock<MarkStackSegment>(region) 66#if !ASSERT_DISABLED 67 , m_top(0) 68#endif 69 { 70 } 71 72 static MarkStackSegment* create(DeadBlock*); 73 74 const JSCell** data() 75 { 76 return bitwise_cast<const JSCell**>(this + 1); 77 } 78 79 static const size_t blockSize = 4 * KB; 80 81#if !ASSERT_DISABLED 82 size_t m_top; 83#endif 84}; 85 86class MarkStackArray { 87public: 88 MarkStackArray(BlockAllocator&); 89 ~MarkStackArray(); 90 91 void append(const JSCell*); 92 93 bool canRemoveLast(); 94 const JSCell* removeLast(); 95 bool refill(); 96 97 void donateSomeCellsTo(MarkStackArray& other); 98 void stealSomeCellsFrom(MarkStackArray& other, size_t idleThreadCount); 99 100 size_t size(); 101 bool isEmpty(); 102 103private: 104 template <size_t size> struct CapacityFromSize { 105 static const size_t value = (size - sizeof(MarkStackSegment)) / sizeof(const JSCell*); 106 }; 107 108 JS_EXPORT_PRIVATE void expand(); 109 110 size_t postIncTop(); 111 size_t preDecTop(); 112 void setTopForFullSegment(); 113 void setTopForEmptySegment(); 114 size_t top(); 115 116 void validatePrevious(); 117 118 DoublyLinkedList<MarkStackSegment> m_segments; 119 BlockAllocator& m_blockAllocator; 120 121 JS_EXPORT_PRIVATE static const size_t s_segmentCapacity = CapacityFromSize<MarkStackSegment::blockSize>::value; 122 size_t m_top; 123 size_t m_numberOfSegments; 124 125}; 126 127} // namespace JSC 128 129#endif 130