1/*
2 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21#ifndef RefCounted_h
22#define RefCounted_h
23
24#include <wtf/Assertions.h>
25#include <wtf/Noncopyable.h>
26
27namespace WTF {
28
29// This base class holds the non-template methods and attributes.
30// The RefCounted class inherits from it reducing the template bloat
31// generated by the compiler (technique called template hoisting).
32class RefCountedBase {
33public:
34 void ref()
35 {
36 ASSERT(!m_deletionHasBegun);
37 ++m_refCount;
38 }
39
40 bool hasOneRef() const
41 {
42 ASSERT(!m_deletionHasBegun);
43 return m_refCount == 1;
44 }
45
46 int refCount() const
47 {
48 return m_refCount;
49 }
50
51protected:
52 RefCountedBase()
53 : m_refCount(1)
54#ifndef NDEBUG
55 , m_deletionHasBegun(false)
56#endif
57 {
58 }
59
60 ~RefCountedBase()
61 {
62 }
63
64 // Returns whether the pointer should be freed or not.
65 bool derefBase()
66 {
67 ASSERT(!m_deletionHasBegun);
68 ASSERT(m_refCount > 0);
69 if (m_refCount == 1) {
70#ifndef NDEBUG
71 m_deletionHasBegun = true;
72#endif
73 return true;
74 }
75
76 --m_refCount;
77 return false;
78 }
79
80 // Helper for generating JIT code. Please do not use for non-JIT purposes.
81 int* addressOfCount()
82 {
83 return &m_refCount;
84 }
85
86#ifndef NDEBUG
87 bool deletionHasBegun() const
88 {
89 return m_deletionHasBegun;
90 }
91#endif
92
93private:
94 template<class T>
95 friend class CrossThreadRefCounted;
96
97 int m_refCount;
98#ifndef NDEBUG
99 bool m_deletionHasBegun;
100#endif
101};
102
103
104template<class T> class RefCounted : public RefCountedBase, public Noncopyable {
105public:
106 void deref()
107 {
108 if (derefBase())
109 delete static_cast<T*>(this);
110 }
111
112protected:
113 ~RefCounted()
114 {
115 }
116};
117
118template<class T> class RefCountedCustomAllocated : public RefCountedBase, public NoncopyableCustomAllocated {
119public:
120 void deref()
121 {
122 if (derefBase())
123 delete static_cast<T*>(this);
124 }
125
126protected:
127 ~RefCountedCustomAllocated()
128 {
129 }
130};
131
132} // namespace WTF
133
134using WTF::RefCounted;
135using WTF::RefCountedCustomAllocated;
136
137#endif // RefCounted_h
138

source code of qtscript/src/3rdparty/javascriptcore/JavaScriptCore/wtf/RefCounted.h