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QoreReferenceCounter.h
1 /* -*- mode: c++; indent-tabs-mode: nil -*- */
2 /*
3  QoreReferenceCounter.h
4 
5  Qore Programming Language
6 
7  Copyright (C) 2003 - 2014 David Nichols, all rights reserved
8 
9  This library is free software; you can redistribute it and/or
10  modify it under the terms of the GNU Lesser General Public
11  License as published by the Free Software Foundation; either
12  version 2.1 of the License, or (at your option) any later version.
13 
14  This library is distributed in the hope that it will be useful,
15  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  Lesser General Public License for more details.
18 
19  You should have received a copy of the GNU Lesser General Public
20  License along with this library; if not, write to the Free Software
21  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23 
24 #ifndef _QORE_QOREREFERENCECOUNTER_H
25 
26 #define _QORE_QOREREFERENCECOUNTER_H
27 
28 #include <qore/common.h>
29 #include <qore/macros.h>
30 
31 class QoreThreadLock;
32 
35 protected:
36  mutable int references;
37 #ifndef HAVE_ATOMIC_MACROS
38  mutable QoreThreadLock mRO;
40 #endif
41 
42 public:
44  DLLEXPORT QoreReferenceCounter();
45 
47  DLLEXPORT ~QoreReferenceCounter();
48 
50 
53  DLLLOCAL int reference_count() const {
54  return references;
55  }
56 
58 
61  DLLLOCAL bool is_unique() const {
62  return references == 1;
63  }
64 
66  DLLEXPORT void ROreference() const;
67 
69 
73  DLLEXPORT bool ROdereference() const;
74 };
75 
76 #endif // _QORE_QOREREFERENCECOUNTER_H
DLLEXPORT bool ROdereference() const
atomically decrements the reference count
QoreThreadLock mRO
pthread lock to ensure atomicity of updates for architectures where we don&#39;t have an atomic increment...
Definition: QoreReferenceCounter.h:39
DLLEXPORT void ROreference() const
atomically increments the reference count
DLLLOCAL int reference_count() const
gets the reference count
Definition: QoreReferenceCounter.h:53
provides atomic reference counting to Qore objects
Definition: QoreReferenceCounter.h:34
DLLLOCAL bool is_unique() const
returns true if the reference count is 1
Definition: QoreReferenceCounter.h:61
provides a mutually-exclusive thread lock
Definition: QoreThreadLock.h:41
DLLEXPORT ~QoreReferenceCounter()
destroys the reference counter object
DLLEXPORT QoreReferenceCounter()
creates the reference counter object