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:
SimpleRefCounted()42       SimpleRefCounted()
43         : rc(0)
44         { }
45 
SimpleRefCounted(unsigned refs_)46       explicit SimpleRefCounted(unsigned refs_)
47         : rc(refs_)
48         { }
49 
~SimpleRefCounted()50       virtual ~SimpleRefCounted()  { }
51 
addRef()52       virtual unsigned addRef()  { return ++rc; }
release()53       virtual unsigned release() { return --rc; }
refs()54       unsigned refs() const      { return rc; }
55   };
56 
57   class AtomicRefCounted : private NonCopyable
58   {
59       mutable volatile atomic_t rc;
60 
61     public:
AtomicRefCounted()62       AtomicRefCounted()
63         : rc(0)
64         { }
65 
AtomicRefCounted(unsigned refs_)66       explicit AtomicRefCounted(unsigned refs_)
67         : rc(refs_)
68         { }
69 
~AtomicRefCounted()70       virtual ~AtomicRefCounted()  { }
71 
addRef()72       virtual atomic_t addRef()  { return atomicIncrement(rc); }
release()73       virtual atomic_t release() { atomic_t ret = atomicDecrement(rc); return ret; }
refs()74       atomic_t refs() const      { return rc; }
75   };
76 
77   typedef SimpleRefCounted RefCounted;
78 }
79 
80 #endif // CXXTOOLS_REFCOUNTED_H
81 
82