1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
/*
* Copyright (C) 2006, 2007, 2009, 2010, 2012 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef TreeShared_h
#define TreeShared_h
#include <wtf/Assertions.h>
#include <wtf/MainThread.h>
#include <wtf/Noncopyable.h>
namespace WebCore {
#ifndef NDEBUG
template<typename NodeType, typename ParentNodeType> class TreeShared;
template<typename NodeType, typename ParentNodeType> void adopted(TreeShared<NodeType, ParentNodeType>*);
#endif
template<typename NodeType, typename ParentNodeType> class TreeShared {
WTF_MAKE_NONCOPYABLE(TreeShared);
protected:
TreeShared()
: m_parent(0)
, m_refCount(1)
#ifndef NDEBUG
, m_adoptionIsRequired(true)
#endif
{
ASSERT(isMainThread());
#ifndef NDEBUG
m_deletionHasBegun = false;
m_inRemovedLastRefFunction = false;
#endif
}
~TreeShared()
{
ASSERT(isMainThread());
ASSERT(!m_refCount);
ASSERT(m_deletionHasBegun);
ASSERT(!m_adoptionIsRequired);
}
public:
void ref()
{
ASSERT(isMainThread());
ASSERT(!m_deletionHasBegun);
ASSERT(!m_inRemovedLastRefFunction);
ASSERT(!m_adoptionIsRequired);
++m_refCount;
}
void deref()
{
ASSERT(isMainThread());
ASSERT(m_refCount >= 0);
ASSERT(!m_deletionHasBegun);
ASSERT(!m_inRemovedLastRefFunction);
ASSERT(!m_adoptionIsRequired);
if (--m_refCount <= 0 && !m_parent) {
#ifndef NDEBUG
m_inRemovedLastRefFunction = true;
#endif
static_cast<NodeType*>(this)->removedLastRef();
}
}
bool hasOneRef() const
{
ASSERT(!m_deletionHasBegun);
ASSERT(!m_inRemovedLastRefFunction);
return m_refCount == 1;
}
int refCount() const
{
return m_refCount;
}
void setParent(ParentNodeType* parent)
{
ASSERT(isMainThread());
m_parent = parent;
}
ParentNodeType* parent() const
{
ASSERT(isMainThreadOrGCThread());
return m_parent;
}
#ifndef NDEBUG
bool m_deletionHasBegun;
bool m_inRemovedLastRefFunction;
#endif
void reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
{
MemoryClassInfo info(memoryObjectInfo, this);
info.addMember(m_parent);
}
private:
#ifndef NDEBUG
friend void adopted<>(TreeShared<NodeType, ParentNodeType>*);
#endif
ParentNodeType* m_parent;
int m_refCount;
#ifndef NDEBUG
bool m_adoptionIsRequired;
#endif
};
#ifndef NDEBUG
template<typename NodeType, typename ParentNodeType> inline void adopted(TreeShared<NodeType, ParentNodeType>* object)
{
if (!object)
return;
ASSERT(!object->m_deletionHasBegun);
ASSERT(!object->m_inRemovedLastRefFunction);
object->m_adoptionIsRequired = false;
}
#endif
}
#endif // TreeShared.h
|
