Mathias Agopian | 1473f46 | 2009-04-10 14:24:30 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2007 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #ifndef ANDROID_UTILS_SINGLETON_H |
| 18 | #define ANDROID_UTILS_SINGLETON_H |
| 19 | |
| 20 | #include <stdint.h> |
| 21 | #include <sys/types.h> |
| 22 | #include <utils/threads.h> |
| 23 | |
| 24 | namespace android { |
| 25 | // --------------------------------------------------------------------------- |
| 26 | |
| 27 | template <typename TYPE> |
| 28 | class Singleton |
| 29 | { |
| 30 | public: |
| 31 | static TYPE& getInstance() { |
| 32 | Mutex::Autolock _l(sLock); |
| 33 | TYPE* instance = sInstance; |
| 34 | if (instance == 0) { |
| 35 | instance = new TYPE(); |
| 36 | sInstance = instance; |
| 37 | } |
| 38 | return *instance; |
| 39 | } |
| 40 | |
| 41 | protected: |
| 42 | ~Singleton() { }; |
| 43 | Singleton() { }; |
| 44 | |
| 45 | private: |
| 46 | Singleton(const Singleton&); |
| 47 | Singleton& operator = (const Singleton&); |
| 48 | static Mutex sLock; |
| 49 | static TYPE* sInstance; |
| 50 | }; |
| 51 | |
Mathias Agopian | 2b1927f | 2009-04-17 14:15:18 -0700 | [diff] [blame] | 52 | /* |
| 53 | * use ANDROID_SINGLETON_STATIC_INSTANCE(TYPE) in your implementation file |
| 54 | * (eg: <TYPE>.cpp) to create the static instance of Singleton<>'s attributes, |
| 55 | * and avoid to have a copy of them in each compilation units Singleton<TYPE> |
| 56 | * is used. |
| 57 | */ |
| 58 | |
| 59 | #define ANDROID_SINGLETON_STATIC_INSTANCE(TYPE) \ |
Mathias Agopian | e9d7445 | 2009-05-28 12:31:31 -0700 | [diff] [blame] | 60 | template class Singleton< TYPE >; \ |
Mathias Agopian | 2b1927f | 2009-04-17 14:15:18 -0700 | [diff] [blame] | 61 | template< class TYPE > Mutex Singleton< TYPE >::sLock; \ |
| 62 | template<> TYPE* Singleton< TYPE >::sInstance(0); |
| 63 | |
| 64 | |
Mathias Agopian | 1473f46 | 2009-04-10 14:24:30 -0700 | [diff] [blame] | 65 | // --------------------------------------------------------------------------- |
| 66 | }; // namespace android |
| 67 | |
| 68 | #endif // ANDROID_UTILS_SINGLETON_H |
| 69 | |