1 // Copyright (C) 2011 The Libphonenumber Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 // Author: Philippe Liard 16 17 #ifndef I18N_PHONENUMBERS_BASE_MEMORY_SINGLETON_H_ 18 #define I18N_PHONENUMBERS_BASE_MEMORY_SINGLETON_H_ 19 20 #if defined(I18N_PHONENUMBERS_USE_BOOST) 21 22 #include <boost/scoped_ptr.hpp> 23 #include <boost/thread/once.hpp> 24 #include <boost/utility.hpp> 25 26 namespace i18n { 27 namespace phonenumbers { 28 29 template <class T> 30 class Singleton : private boost::noncopyable { 31 public: ~Singleton()32 virtual ~Singleton() {} 33 GetInstance()34 static T* GetInstance() { 35 boost::call_once(Init, flag); 36 return instance.get(); 37 } 38 39 private: Init()40 static void Init() { 41 instance.reset(new T()); 42 } 43 44 static boost::scoped_ptr<T> instance; 45 static boost::once_flag flag; 46 }; 47 48 template <class T> boost::scoped_ptr<T> Singleton<T>::instance; 49 template <class T> boost::once_flag Singleton<T>::flag = BOOST_ONCE_INIT; 50 51 } // namespace phonenumbers 52 } // namespace i18n 53 54 #else // !I18N_PHONENUMBERS_USE_BOOST 55 56 #include "phonenumbers/base/logging.h" 57 #include "phonenumbers/base/thread_checker.h" 58 59 #if !defined(__linux__) && !defined(__APPLE__) 60 61 namespace i18n { 62 namespace phonenumbers { 63 64 // Note that this implementation is not thread-safe. For a thread-safe 65 // implementation on non-POSIX platforms, please compile with 66 // -DI18N_PHONENUMBERS_USE_BOOST. 67 template <class T> 68 class Singleton { 69 public: Singleton()70 Singleton() : thread_checker_() {} 71 ~Singleton()72 virtual ~Singleton() {} 73 GetInstance()74 static T* GetInstance() { 75 static T* instance = NULL; 76 if (!instance) { 77 instance = new T(); 78 } 79 DCHECK(instance->thread_checker_.CalledOnValidThread()); 80 return instance; 81 } 82 83 private: 84 const ThreadChecker thread_checker_; 85 }; 86 87 } // namespace phonenumbers 88 } // namespace i18n 89 90 #else 91 #include "phonenumbers/base/memory/singleton_posix.h" 92 #endif // !defined(__linux__) && !defined(__APPLE__) 93 94 #endif // !I18N_PHONENUMBERS_USE_BOOST 95 #endif // I18N_PHONENUMBERS_BASE_MEMORY_SINGLETON_H_ 96