A Discrete-Event Network Simulator
API
Loading...
Searching...
No Matches
singleton.h
Go to the documentation of this file.
1/*
2 * Copyright (c) 2007 INRIA
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation;
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 *
17 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
18 */
19#ifndef SINGLETON_H
20#define SINGLETON_H
21
22/**
23 * \file
24 * \ingroup singleton
25 * ns3::Singleton declaration and template implementation.
26 */
27
28namespace ns3
29{
30
31/**
32 * \ingroup core
33 * \defgroup singleton Singleton
34 *
35 * Template class implementing the Singleton design pattern.
36 */
37
38/**
39 * \ingroup singleton
40 * \brief A template singleton
41 *
42 * This template class can be used to implement the singleton pattern.
43 * The underlying object will be destroyed automatically when the process
44 * exits.
45 *
46 * For a singleton whose lifetime is bounded by the simulation run,
47 * not the process, see SimulationSingleton.
48 *
49 * To force your `class ExampleS` to be a singleton, inherit from Singleton:
50 * \code
51 * class ExampleS : public Singleton<ExampleS> { ... };
52 * \endcode
53 *
54 * Then, to reach the singleton instance, just do
55 * \code
56 * ExampleS::Get ()->...;
57 * \endcode
58 *
59 * \note
60 * If you call Get() again after the object has
61 * been destroyed, the object will be re-created which will result in a
62 * memory leak as reported by most memory leak checkers. It is up to the
63 * user to ensure that Get() is never called from a static variable
64 * finalizer.
65 */
66template <typename T>
67class Singleton
68{
69 public:
70 // Delete copy constructor and assignment operator to avoid misuse
71 Singleton(const Singleton<T>&) = delete;
72 Singleton& operator=(const Singleton<T>&) = delete;
73
74 /**
75 * Get a pointer to the singleton instance.
76 *
77 * The instance will be automatically deleted when
78 * the process exits.
79 *
80 * \return A pointer to the singleton instance.
81 */
82 static T* Get();
83
84 protected:
85 /** Constructor. */
86 Singleton()
87 {
88 }
89
90 /** Destructor. */
91 virtual ~Singleton()
92 {
93 }
94};
95
96} // namespace ns3
97
98/********************************************************************
99 * Implementation of the templates declared above.
100 ********************************************************************/
101
102namespace ns3
103{
104
105template <typename T>
106T*
107Singleton<T>::Get()
108{
109 static T object;
110 return &object;
111}
112
113} // namespace ns3
114
115#endif /* SINGLETON_H */
ns3::Singleton
A template singleton.
Definition: singleton.h:68
ns3::Singleton::Singleton
Singleton(const Singleton< T > &)=delete
ns3::Singleton::operator=
Singleton & operator=(const Singleton< T > &)=delete
ns3::Singleton::Get
static T * Get()
Get a pointer to the singleton instance.
Definition: singleton.h:107
ns3::Singleton::Singleton
Singleton()
Constructor.
Definition: singleton.h:86
ns3::Singleton::~Singleton
virtual ~Singleton()
Destructor.
Definition: singleton.h:91
ns3
Every class exported by the ns3 library is enclosed in the ns3 namespace.