/*
 * Copyright (C) 2016 Rockchip Electronics Co., Ltd.
 * Authors:
 *    Zhiqin Wei <wzq@rock-chips.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#ifndef _LIBS_RGA_SINGLETON_H
#define _LIBS_RGA_SINGLETON_H

#include "RgaMutex.h"

#if defined(__clang__)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wundefined-var-template"
#endif

template <typename TYPE>
class RgaSingleton {
public:
    static TYPE& getInstance()
    {
        Mutex::Autolock _l(sLock);
        TYPE* instance = sInstance;
        if (instance == nullptr) {
            instance = new TYPE();
            sInstance = instance;
        }
        return *instance;
    }
    static bool hasInstance()
    {
        Mutex::Autolock _l(sLock);
        return sInstance != nullptr;
    }

protected:
    ~RgaSingleton() { }
    RgaSingleton() { }

private:
    RgaSingleton(const RgaSingleton&);
    RgaSingleton& operator = (const RgaSingleton&);
    static Mutex sLock;
    static TYPE* sInstance;
};

#if defined(__clang__)
#pragma clang diagnostic pop
#endif

#define RGA_SINGLETON_STATIC_INSTANCE(TYPE) do { \
    template<> ::RgaMutex  \
        (::RgaSingleton< TYPE >::sLock)(::RgaMutex::PRIVATE);  \
    template<> TYPE* ::RgaSingleton< TYPE >::sInstance(nullptr);  /* NOLINT */ \
    template class ::RgaSingleton< TYPE >; \
} while (0)

#endif // _LIBS_RGA_SINGLETON_H