OpenMesh
SingletonT.hh
1 /* ========================================================================= *
2  * *
3  * OpenMesh *
4  * Copyright (c) 2001-2015, RWTH-Aachen University *
5  * Department of Computer Graphics and Multimedia *
6  * All rights reserved. *
7  * www.openmesh.org *
8  * *
9  *---------------------------------------------------------------------------*
10  * This file is part of OpenMesh. *
11  *---------------------------------------------------------------------------*
12  * *
13  * Redistribution and use in source and binary forms, with or without *
14  * modification, are permitted provided that the following conditions *
15  * are met: *
16  * *
17  * 1. Redistributions of source code must retain the above copyright notice, *
18  * this list of conditions and the following disclaimer. *
19  * *
20  * 2. Redistributions in binary form must reproduce the above copyright *
21  * notice, this list of conditions and the following disclaimer in the *
22  * documentation and/or other materials provided with the distribution. *
23  * *
24  * 3. Neither the name of the copyright holder nor the names of its *
25  * contributors may be used to endorse or promote products derived from *
26  * this software without specific prior written permission. *
27  * *
28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS *
29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED *
30  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A *
31  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER *
32  * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, *
33  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, *
34  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR *
35  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF *
36  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING *
37  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS *
38  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *
39  * *
40  * ========================================================================= */
41 
42 /*===========================================================================*\
43  * *
44  * $Revision$ *
45  * $Date$ *
46  * *
47 \*===========================================================================*/
48 
49 
50 //=============================================================================
51 //
52 // Implements a simple singleton template
53 //
54 //=============================================================================
55 
56 
57 #ifndef __SINGLETON_HH__
58 #define __SINGLETON_HH__
59 
60 
61 //=== INCLUDES ================================================================
62 
63 // OpenMesh
64 #include <OpenMesh/Core/System/config.h>
65 
66 // STL
67 #include <stdexcept>
68 
69 
70 //== NAMESPACES ===============================================================
71 
72 
73 namespace OpenMesh {
74 
75 
76 //=== IMPLEMENTATION ==========================================================
77 
78 
83 template <typename T>
85 {
86 public:
87 
94  static T& Instance()
95  {
96  if (!pInstance__)
97  {
98  // check if singleton alive
99  if (destroyed__)
100  {
101  OnDeadReference();
102  }
103  // first time request -> initialize
104  else
105  {
106  Create();
107  }
108  }
109  return *pInstance__;
110  }
111 
112 
113 private:
114 
115  // Disable constructors/assignment to enforce uniqueness
116  SingletonT();
117  SingletonT(const SingletonT&);
118  SingletonT& operator=(const SingletonT&);
119 
120  // Create a new singleton and store its pointer
121  static void Create()
122  {
123  static T theInstance;
124  pInstance__ = &theInstance;
125  }
126 
127  // Will be called if instance is accessed after its lifetime has expired
128  static void OnDeadReference()
129  {
130  throw std::runtime_error("[Singelton error] - Dead reference detected!\n");
131  }
132 
133  virtual ~SingletonT()
134  {
135  pInstance__ = 0;
136  destroyed__ = true;
137  }
138 
139  static T* pInstance__;
140  static bool destroyed__;
141 };
142 
143 
144 
145 //=============================================================================
146 } // namespace OpenMesh
147 //=============================================================================
148 #if defined(OM_INCLUDE_TEMPLATES) && !defined(OPENMESH_SINGLETON_C)
149 # define OPENMESH_SINGLETON_TEMPLATES
150 # include "SingletonT.cc"
151 #endif
152 //=============================================================================
153 #endif // __SINGLETON_HH__
154 //=============================================================================
static T & Instance()
Singleton access function.
Definition: SingletonT.hh:94
A simple singleton template.
Definition: SingletonT.hh:84
Contains all the mesh ingredients like the polygonal mesh, the triangle mesh, different mesh kernels ...
Definition: MeshItems.hh:64

Project OpenMesh, ©  Computer Graphics Group, RWTH Aachen. Documentation generated using doxygen .