2 * Copyright (C) 2009, 2011 Apple Inc. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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.
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.
27 #include "MarkStack.h"
29 #include "ConservativeRoots.h"
34 #include "ScopeChain.h"
35 #include "Structure.h"
39 void MarkStack::reset()
41 m_values.shrinkAllocation(pageSize());
42 m_markSets.shrinkAllocation(pageSize());
43 m_opaqueRoots.clear();
46 void MarkStack::append(ConservativeRoots& conservativeRoots)
48 JSCell** roots = conservativeRoots.roots();
49 size_t size = conservativeRoots.size();
50 for (size_t i = 0; i < size; ++i)
51 internalAppend(roots[i]);
54 inline void SlotVisitor::visitChildren(JSCell* cell)
56 #if ENABLE(SIMPLE_HEAP_PROFILING)
57 m_visitedTypeCounts.count(cell);
60 ASSERT(Heap::isMarked(cell));
61 if (cell->structure()->typeInfo().type() < CompoundType) {
62 cell->JSCell::visitChildren(*this);
66 if (!cell->structure()->typeInfo().overridesVisitChildren()) {
67 ASSERT(cell->isObject());
69 asObject(cell)->visitChildrenDirect(*this);
71 ASSERT(!m_isCheckingForDefaultMarkViolation);
72 m_isCheckingForDefaultMarkViolation = true;
73 cell->visitChildren(*this);
74 ASSERT(m_isCheckingForDefaultMarkViolation);
75 m_isCheckingForDefaultMarkViolation = false;
79 if (cell->vptr() == m_jsArrayVPtr) {
80 asArray(cell)->visitChildrenDirect(*this);
83 cell->visitChildren(*this);
86 void SlotVisitor::drain()
89 ASSERT(!m_isDraining);
92 while (!m_markSets.isEmpty() || !m_values.isEmpty()) {
93 while (!m_markSets.isEmpty() && m_values.size() < 50) {
94 ASSERT(!m_markSets.isEmpty());
95 MarkSet& current = m_markSets.last();
96 ASSERT(current.m_values);
97 JSValue* end = current.m_end;
98 ASSERT(current.m_values);
99 ASSERT(current.m_values != end);
100 findNextUnmarkedNullValue:
101 ASSERT(current.m_values != end);
102 JSValue value = *current.m_values;
106 if (!value || !value.isCell() || Heap::testAndSetMarked(cell = value.asCell())) {
107 if (current.m_values == end) {
108 m_markSets.removeLast();
111 goto findNextUnmarkedNullValue;
114 if (cell->structure()->typeInfo().type() < CompoundType) {
115 #if ENABLE(SIMPLE_HEAP_PROFILING)
116 m_visitedTypeCounts.count(cell);
118 cell->JSCell::visitChildren(*this);
119 if (current.m_values == end) {
120 m_markSets.removeLast();
123 goto findNextUnmarkedNullValue;
126 if (current.m_values == end)
127 m_markSets.removeLast();
131 while (!m_values.isEmpty())
132 visitChildren(m_values.removeLast());
135 m_isDraining = false;
139 void SlotVisitor::harvestWeakReferences()
141 while (m_firstWeakReferenceHarvester) {
142 WeakReferenceHarvester* current = m_firstWeakReferenceHarvester;
143 WeakReferenceHarvester* next = reinterpret_cast<WeakReferenceHarvester*>(current->m_nextAndFlag & ~1);
144 current->m_nextAndFlag = 0;
145 m_firstWeakReferenceHarvester = next;
146 current->visitWeakReferences(*this);
150 #if ENABLE(GC_VALIDATION)
151 void MarkStack::validateSet(JSValue* values, size_t count)
153 for (size_t i = 0; i < count; i++) {
155 validateValue(values[i]);
159 void MarkStack::validateValue(JSValue value)
165 JSCell* cell = value.asCell();
169 if (!cell->structure())
172 // Both the cell's structure, and the cell's structure's structure should be the Structure Structure.
173 // I hate this sentence.
174 if (cell->structure()->structure()->JSCell::classInfo() != cell->structure()->JSCell::classInfo())
178 void MarkStack::validateValue(JSValue)