refcounted.h
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1 /*
2  * Copyright (C) 2005 Tommi Maekitalo
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * As a special exception, you may use this file as part of a free
10  * software library without restriction. Specifically, if other files
11  * instantiate templates or use macros or inline functions from this
12  * file, or you compile this file and link it with other files to
13  * produce an executable, this file does not by itself cause the
14  * resulting executable to be covered by the GNU General Public
15  * License. This exception does not however invalidate any other
16  * reasons why the executable file might be covered by the GNU Library
17  * General Public License.
18  *
19  * This library is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22  * Lesser General Public License for more details.
23  *
24  * You should have received a copy of the GNU Lesser General Public
25  * License along with this library; if not, write to the Free Software
26  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27  */
28 
29 #ifndef CXXTOOLS_REFCOUNTED_H
30 #define CXXTOOLS_REFCOUNTED_H
31 
32 #include <cxxtools/noncopyable.h>
33 #include <cxxtools/atomicity.h>
34 
35 namespace cxxtools
36 {
37  class SimpleRefCounted : private NonCopyable
38  {
39  unsigned rc;
40 
41  public:
43  : rc(0)
44  { }
45 
46  explicit SimpleRefCounted(unsigned refs_)
47  : rc(refs_)
48  { }
49 
50  virtual ~SimpleRefCounted() { }
51 
52  virtual unsigned addRef() { return ++rc; }
53  virtual unsigned release() { return --rc; }
54  unsigned refs() const { return rc; }
55  };
56 
57  class AtomicRefCounted : private NonCopyable
58  {
59  mutable volatile atomic_t rc;
60 
61  public:
63  : rc(0)
64  { }
65 
66  explicit AtomicRefCounted(unsigned refs_)
67  : rc(refs_)
68  { }
69 
70  virtual ~AtomicRefCounted() { }
71 
72  virtual atomic_t addRef() { return atomicIncrement(rc); }
73  virtual atomic_t release() { atomic_t ret = atomicDecrement(rc); return ret; }
74  atomic_t refs() const { return rc; }
75  };
76 
78 }
79 
80 #endif // CXXTOOLS_REFCOUNTED_H
81