1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2014 Google Inc. All rights reserved. 3 // https://developers.google.com/protocol-buffers/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 #ifndef GOOGLE_PROTOBUF_STUBS_SINGLETON_H__ 31 #define GOOGLE_PROTOBUF_STUBS_SINGLETON_H__ 32 33 #include <google/protobuf/stubs/atomicops.h> 34 #include <google/protobuf/stubs/common.h> 35 #include <google/protobuf/stubs/once.h> 36 37 namespace google { 38 namespace protobuf { 39 namespace internal { 40 template<typename T> 41 class Singleton { 42 public: 43 static T* get() { 44 GoogleOnceInit(&once_, &Singleton<T>::Init); 45 return instance_; 46 } 47 static void ShutDown() { 48 delete instance_; 49 instance_ = NULL; 50 } 51 private: 52 static void Init() { 53 instance_ = new T(); 54 } 55 static ProtobufOnceType once_; 56 static T* instance_; 57 }; 58 59 template<typename T> 60 ProtobufOnceType Singleton<T>::once_; 61 62 template<typename T> 63 T* Singleton<T>::instance_ = NULL; 64 } // namespace internal 65 } // namespace protobuf 66 } // namespace google 67 68 #endif // GOOGLE_PROTOBUF_STUBS_SINGLETON_H__ 69
