c777f213b3
The ANDROID_SINGLETON_STATIC_INSTANCE is used in some files out of the android namespace. If it does not use full qualified names, users of this macro will need to use it inside the 'android' namespace to avoid warnings from clang compiler. Change-Id: Ie4d4ba2b57fdc72d0deb3b7c2326304a44a1300f
78 lines
2.3 KiB
C++
78 lines
2.3 KiB
C++
/*
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* Copyright (C) 2007 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef ANDROID_UTILS_SINGLETON_H
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#define ANDROID_UTILS_SINGLETON_H
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#include <stdint.h>
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#include <sys/types.h>
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#include <utils/threads.h>
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#include <cutils/compiler.h>
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namespace android {
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// ---------------------------------------------------------------------------
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template <typename TYPE>
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class ANDROID_API Singleton
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{
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public:
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static TYPE& getInstance() {
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Mutex::Autolock _l(sLock);
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TYPE* instance = sInstance;
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if (instance == 0) {
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instance = new TYPE();
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sInstance = instance;
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}
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return *instance;
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}
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static bool hasInstance() {
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Mutex::Autolock _l(sLock);
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return sInstance != 0;
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}
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protected:
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~Singleton() { };
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Singleton() { };
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private:
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Singleton(const Singleton&);
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Singleton& operator = (const Singleton&);
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static Mutex sLock;
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static TYPE* sInstance;
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};
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/*
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* use ANDROID_SINGLETON_STATIC_INSTANCE(TYPE) in your implementation file
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* (eg: <TYPE>.cpp) to create the static instance of Singleton<>'s attributes,
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* and avoid to have a copy of them in each compilation units Singleton<TYPE>
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* is used.
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* NOTE: we use a version of Mutex ctor that takes a parameter, because
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* for some unknown reason using the default ctor doesn't emit the variable!
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*/
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#define ANDROID_SINGLETON_STATIC_INSTANCE(TYPE) \
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template<> ::android::Mutex \
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(::android::Singleton< TYPE >::sLock)(::android::Mutex::PRIVATE); \
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template<> TYPE* ::android::Singleton< TYPE >::sInstance(0); \
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template class ::android::Singleton< TYPE >;
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// ---------------------------------------------------------------------------
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}; // namespace android
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#endif // ANDROID_UTILS_SINGLETON_H
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