refcounted.h
Go to the documentation of this file.
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/atomicity.h>
33 
34 namespace cxxtools
35 {
37  {
38  unsigned rc;
39 
40  public:
42  : rc(0)
43  { }
44 
45  explicit SimpleRefCounted(unsigned refs_)
46  : rc(refs_)
47  { }
48 
49  virtual ~SimpleRefCounted() { }
50 
51  virtual unsigned addRef() { return ++rc; }
52  virtual unsigned release() { return --rc; }
53  unsigned refs() const { return rc; }
54  };
55 
57  {
58  mutable volatile atomic_t rc;
59 
60  public:
62  : rc(0)
63  { }
64 
65  explicit AtomicRefCounted(unsigned refs_)
66  : rc(refs_)
67  { }
68 
69  virtual ~AtomicRefCounted() { }
70 
71  virtual atomic_t addRef() { return atomicIncrement(rc); }
72  virtual atomic_t release() { atomic_t ret = atomicDecrement(rc); return ret; }
73  atomic_t refs() const { return rc; }
74  };
75 
77 }
78 
79 #endif // CXXTOOLS_REFCOUNTED_H
80