Qore Programming Language - C/C++ Library  0.8.12.3
QoreReferenceCounter.h
1 /* -*- mode: c++; indent-tabs-mode: nil -*- */
2 /*
3  QoreReferenceCounter.h
4 
5  Qore Programming Language
6 
7  Copyright (C) 2003 - 2015 David Nichols
8 
9  Permission is hereby granted, free of charge, to any person obtaining a
10  copy of this software and associated documentation files (the "Software"),
11  to deal in the Software without restriction, including without limitation
12  the rights to use, copy, modify, merge, publish, distribute, sublicense,
13  and/or sell copies of the Software, and to permit persons to whom the
14  Software is furnished to do so, subject to the following conditions:
15 
16  The above copyright notice and this permission notice shall be included in
17  all copies or substantial portions of the Software.
18 
19  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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23  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25  DEALINGS IN THE SOFTWARE.
26 
27  Note that the Qore library is released under a choice of three open-source
28  licenses: MIT (as above), LGPL 2+, or GPL 2+; see README-LICENSE for more
29  information.
30 */
31 
32 #ifndef _QORE_QOREREFERENCECOUNTER_H
33 
34 #define _QORE_QOREREFERENCECOUNTER_H
35 
36 #include <qore/common.h>
37 #include <qore/macros.h>
38 
39 class QoreThreadLock;
40 
43 protected:
44  mutable int references;
45 #ifndef HAVE_ATOMIC_MACROS
46  mutable QoreThreadLock mRO;
48 #endif
49 
50 public:
52  DLLEXPORT QoreReferenceCounter();
53 
55  DLLEXPORT ~QoreReferenceCounter();
56 
58 
61  DLLLOCAL int reference_count() const {
62  return references;
63  }
64 
66 
69  DLLLOCAL bool is_unique() const {
70  return references == 1;
71  }
72 
74  DLLEXPORT void ROreference() const;
75 
77 
81  DLLEXPORT bool ROdereference() const;
82 };
83 
84 #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't have an atomic increment...
Definition: QoreReferenceCounter.h:47
DLLEXPORT void ROreference() const
atomically increments the reference count
DLLLOCAL int reference_count() const
gets the reference count
Definition: QoreReferenceCounter.h:61
provides atomic reference counting to Qore objects
Definition: QoreReferenceCounter.h:42
DLLLOCAL bool is_unique() const
returns true if the reference count is 1
Definition: QoreReferenceCounter.h:69
provides a mutually-exclusive thread lock
Definition: QoreThreadLock.h:49
DLLEXPORT ~QoreReferenceCounter()
destroys the reference counter object
DLLEXPORT QoreReferenceCounter()
creates the reference counter object