1/*
2 * Copyright (C) 2012 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#ifndef WeakSet_h
27#define WeakSet_h
28
29#include "WeakBlock.h"
30
31namespace JSC {
32
33class Heap;
34class MarkedBlock;
35class WeakImpl;
36
37class WeakSet {
38 friend class LLIntOffsetsExtractor;
39
40public:
41 static WeakImpl* allocate(JSValue, WeakHandleOwner* = 0, void* context = 0);
42 static void deallocate(WeakImpl*);
43
44 WeakSet(VM*, MarkedBlock&);
45 ~WeakSet();
46 void lastChanceToFinalize();
47
48 Heap* heap() const;
49 VM* vm() const;
50
51 bool isEmpty() const;
52
53 void visit(HeapRootVisitor&);
54 void reap();
55 void sweep();
56 void shrink();
57 void resetAllocator();
58
59private:
60 JS_EXPORT_PRIVATE WeakBlock::FreeCell* findAllocator();
61 WeakBlock::FreeCell* tryFindAllocator();
62 WeakBlock::FreeCell* addAllocator();
63 void removeAllocator(WeakBlock*);
64
65 WeakBlock::FreeCell* m_allocator;
66 WeakBlock* m_nextAllocator;
67 DoublyLinkedList<WeakBlock> m_blocks;
68 VM* m_vm;
69 MarkedBlock& m_markedBlock;
70};
71
72inline WeakSet::WeakSet(VM* vm, MarkedBlock& markedBlock)
73 : m_allocator(0)
74 , m_nextAllocator(0)
75 , m_vm(vm)
76 , m_markedBlock(markedBlock)
77{
78}
79
80inline VM* WeakSet::vm() const
81{
82 return m_vm;
83}
84
85inline bool WeakSet::isEmpty() const
86{
87 for (WeakBlock* block = m_blocks.head(); block; block = block->next()) {
88 if (!block->isEmpty())
89 return false;
90 }
91
92 return true;
93}
94
95inline void WeakSet::deallocate(WeakImpl* weakImpl)
96{
97 weakImpl->setState(WeakImpl::Deallocated);
98}
99
100inline void WeakSet::lastChanceToFinalize()
101{
102 for (WeakBlock* block = m_blocks.head(); block; block = block->next())
103 block->lastChanceToFinalize();
104}
105
106inline void WeakSet::visit(HeapRootVisitor& visitor)
107{
108 for (WeakBlock* block = m_blocks.head(); block; block = block->next())
109 block->visit(visitor);
110}
111
112inline void WeakSet::reap()
113{
114 for (WeakBlock* block = m_blocks.head(); block; block = block->next())
115 block->reap();
116}
117
118inline void WeakSet::shrink()
119{
120 WeakBlock* next;
121 for (WeakBlock* block = m_blocks.head(); block; block = next) {
122 next = block->next();
123
124 if (block->isEmpty())
125 removeAllocator(block);
126 }
127
128 resetAllocator();
129}
130
131inline void WeakSet::resetAllocator()
132{
133 m_allocator = 0;
134 m_nextAllocator = m_blocks.head();
135}
136
137} // namespace JSC
138
139#endif // WeakSet_h
140