1 | // |
2 | // RefCountedObject.h |
3 | // |
4 | // Library: Foundation |
5 | // Package: Core |
6 | // Module: RefCountedObject |
7 | // |
8 | // Definition of the RefCountedObject class. |
9 | // |
10 | // Copyright (c) 2004-2009, Applied Informatics Software Engineering GmbH. |
11 | // and Contributors. |
12 | // |
13 | // SPDX-License-Identifier: BSL-1.0 |
14 | // |
15 | |
16 | |
17 | #ifndef Foundation_RefCountedObject_INCLUDED |
18 | #define Foundation_RefCountedObject_INCLUDED |
19 | |
20 | |
21 | #include "Poco/Foundation.h" |
22 | #include "Poco/AtomicCounter.h" |
23 | |
24 | |
25 | namespace Poco { |
26 | |
27 | |
28 | class Foundation_API RefCountedObject |
29 | /// A base class for objects that employ |
30 | /// reference counting based garbage collection. |
31 | /// |
32 | /// Reference-counted objects inhibit construction |
33 | /// by copying and assignment. |
34 | { |
35 | public: |
36 | RefCountedObject(); |
37 | /// Creates the RefCountedObject. |
38 | /// The initial reference count is one. |
39 | |
40 | void duplicate() const; |
41 | /// Increments the object's reference count. |
42 | |
43 | void release() const throw(); |
44 | /// Decrements the object's reference count |
45 | /// and deletes the object if the count |
46 | /// reaches zero. |
47 | |
48 | int referenceCount() const; |
49 | /// Returns the reference count. |
50 | |
51 | protected: |
52 | virtual ~RefCountedObject(); |
53 | /// Destroys the RefCountedObject. |
54 | |
55 | private: |
56 | RefCountedObject(const RefCountedObject&); |
57 | RefCountedObject& operator = (const RefCountedObject&); |
58 | |
59 | mutable AtomicCounter _counter; |
60 | }; |
61 | |
62 | |
63 | // |
64 | // inlines |
65 | // |
66 | inline int RefCountedObject::referenceCount() const |
67 | { |
68 | return _counter.value(); |
69 | } |
70 | |
71 | |
72 | inline void RefCountedObject::duplicate() const |
73 | { |
74 | ++_counter; |
75 | } |
76 | |
77 | |
78 | inline void RefCountedObject::release() const throw() |
79 | { |
80 | try |
81 | { |
82 | if (--_counter == 0) delete this; |
83 | } |
84 | catch (...) |
85 | { |
86 | poco_unexpected(); |
87 | } |
88 | } |
89 | |
90 | |
91 | } // namespace Poco |
92 | |
93 | |
94 | #endif // Foundation_RefCountedObject_INCLUDED |
95 | |