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 
27 namespace WTF
28 {
29 
30 template<class T> class RefCounted : Noncopyable
31 {
32 public:
33     RefCounted(int initialRefCount = 1)
m_refCount(initialRefCount)34         : m_refCount(initialRefCount)
35 #ifndef NDEBUG
36         , m_deletionHasBegun(false)
37 #endif
38     {
39     }
40 
ref()41     void ref()
42     {
43         ASSERT(!m_deletionHasBegun);
44         ++m_refCount;
45     }
46 
deref()47     void deref()
48     {
49         ASSERT(!m_deletionHasBegun);
50         ASSERT(m_refCount > 0);
51         if (m_refCount == 1) {
52 #ifndef NDEBUG
53             m_deletionHasBegun = true;
54 #endif
55             delete static_cast<T *>(this);
56         } else {
57             --m_refCount;
58         }
59     }
60 
hasOneRef()61     bool hasOneRef()
62     {
63         ASSERT(!m_deletionHasBegun);
64         return m_refCount == 1;
65     }
66 
refCount()67     int refCount() const
68     {
69         return m_refCount;
70     }
71 
72 private:
73     int m_refCount;
74 #ifndef NDEBUG
75     bool m_deletionHasBegun;
76 #endif
77 };
78 
79 } // namespace WTF
80 
81 using WTF::RefCounted;
82 
83 #endif // RefCounted_h
84