00001 // 00002 // SingletonHolder.h 00003 // 00004 // $Id: //poco/1.3/Foundation/include/Poco/SingletonHolder.h#1 $ 00005 // 00006 // Library: Foundation 00007 // Package: Core 00008 // Module: SingletonHolder 00009 // 00010 // Definition of the SingletonHolder template. 00011 // 00012 // Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH. 00013 // and Contributors. 00014 // 00015 // Permission is hereby granted, free of charge, to any person or organization 00016 // obtaining a copy of the software and accompanying documentation covered by 00017 // this license (the "Software") to use, reproduce, display, distribute, 00018 // execute, and transmit the Software, and to prepare derivative works of the 00019 // Software, and to permit third-parties to whom the Software is furnished to 00020 // do so, all subject to the following: 00021 // 00022 // The copyright notices in the Software and this entire statement, including 00023 // the above license grant, this restriction and the following disclaimer, 00024 // must be included in all copies of the Software, in whole or in part, and 00025 // all derivative works of the Software, unless such copies or derivative 00026 // works are solely in the form of machine-executable object code generated by 00027 // a source language processor. 00028 // 00029 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 00030 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 00031 // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT 00032 // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE 00033 // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, 00034 // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 00035 // DEALINGS IN THE SOFTWARE. 00036 // 00037 00038 00039 #ifndef Foundation_SingletonHolder_INCLUDED 00040 #define Foundation_SingletonHolder_INCLUDED 00041 00042 00043 #include "Poco/Foundation.h" 00044 #include "Poco/Mutex.h" 00045 00046 00047 namespace Poco { 00048 00049 00050 template <class S> 00051 class SingletonHolder 00057 { 00058 public: 00059 SingletonHolder() 00061 { 00062 _pS = 0; 00063 } 00064 ~SingletonHolder() 00067 { 00068 delete _pS; 00069 } 00070 S* get() 00074 { 00075 FastMutex::ScopedLock lock(_m); 00076 if (!_pS) _pS = new S; 00077 return _pS; 00078 } 00079 00080 private: 00081 S* _pS; 00082 FastMutex _m; 00083 }; 00084 00085 00086 } // namespace Poco 00087 00088 00089 #endif // Foundation_SingletonHolder_INCLUDED