题目二：实现单例模式

////////////////////////////////////////////////////////////////////////////////////////////////////////
// 4.单例模式测试

extern CMutex g_stMutex;    // 这个在ThreadTest.cpp中定义了，这个声明一下！！！！

class CSingletonTest
{
public:
    CSingletonTest() :m_iCount(0){}
    ~CSingletonTest(){}
    void AddCount() { m_iCount++; }
    void SubCount() { m_iCount--; }
    int GetCount() { return m_iCount; }

private:
    int m_iCount;
};

class CSingleton_1
{
protected:
    // 禁止外部调用这几个函数
    CSingleton_1(){}
    ~CSingleton_1(){}
    CSingleton_1(const CSingleton_1&);
    CSingleton_1& operator=(const CSingleton_1&);

};

///////////////////////////////////////////////////////
// 懒汉模式 
//类加载进来，没有对象，只有调用了getInstance方法时，才会创建对象。
//延迟加载形式。 并发过程中存在安全隐患。

template <typename TYPE>
class CSingleton_2 : public CSingleton_1
{
public:
    static TYPE* GetInstance()
    {
        if (NULL == m_pSingleton)
        {
            cout << "Try Lock --------------->" << endl;
            m_pSingleton = new CSingleton_2<TYPE>();
        }

        return &m_pSingleton->m_stInstance;
    }
private:
    static CSingleton_2<TYPE>* m_pSingleton;
    TYPE m_stInstance;

private:
    // 自动释放内存(不需要定义也可以，程序结束是系统会自动回收)
    class CGarbo
    {
    public:
        ~CGarbo()
        {
            if (m_pSingleton)
            {
                delete m_pSingleton;
                m_pSingleton = NULL;
            }
        }
    };

    static CGarbo garbo;
};

template <typename TYPE>
CSingleton_2<TYPE>* CSingleton_2<TYPE>::m_pSingleton;

typedef CSingleton_2<CSingletonTest> SingletonTesHEAP_TYPE;

////////////////////////////////////////////////////////////
// 加锁的懒汉实现
template <typename TYPE>
class CSingleton_3 : public CSingleton_1
{
public:
    static TYPE* GetInstance()
    {
        if (NULL == m_pSingleton)
        {
            cout << "Try Lock --------------->" << endl;
            CLock lock(g_stMutex);
            if (NULL == m_pSingleton)
            {
                m_pSingleton = new CSingleton_3<TYPE>();
            }
        }
        return &m_pSingleton->m_stInstance;
    }
private:
    static CSingleton_3<TYPE>* m_pSingleton;
    TYPE m_stInstance;
};

template <typename TYPE>
CSingleton_3<TYPE>* CSingleton_3<TYPE>::m_pSingleton;

typedef CSingleton_3<CSingletonTest> SingletonTest3;


////////////////////////////////////////////////////////////////
// 饿汉模式
template <typename TYPE>
class CSingleton_4 : public CSingleton_1
{
public:
    static TYPE* GetInstance()
    {
        //return &(const_cast<CSingleton2<TYPE>*>(m_pSingleton)->m_stInstance);
        return &(const_cast<CSingleton_4<TYPE>*>(m_pSingleton)->m_stInstance);
    }
private:
    const static CSingleton_4<TYPE>* m_pSingleton;
    TYPE m_stInstance;
};

template <typename TYPE>
const CSingleton_4<TYPE>* CSingleton_4<TYPE>::m_pSingleton = new CSingleton_4<TYPE>;
typedef CSingleton_4<CSingletonTest> SingletonTest4;


////////////////////////////////////////////////////////////////////////
// 多线程测试函数
template <typename TYPE>
class CSingletonThreadTest : public CThread
{
public:
    CSingletonThreadTest(const string& str) :m_szThreadName(str) {}
    ~CSingletonThreadTest(){}

    virtual void Run()
    {
        for (int i = 0; i < 5000; i++)
        {
            //CLock Lock(g_stMutex);
            TYPE::GetInstance()->AddCount();
            //cout << m_szThreadName << ": " << TYPE::GetInstance()->GetCount() << endl;
        }
    }

private:
    string m_szThreadName;
};

void CSingleton_2TestFunc()
{
    cout << "\n\n --------------- CSingleton_2TestFunc Start -------------->" << endl;
    double dStart = clock();

    // 1.单线程测试
    CSingletonTest* pTest = SingletonTesHEAP_TYPE::GetInstance();
    pTest->AddCount();
    cout << "pTest Count = " << pTest->GetCount() << endl;

    // pTest 和 pTesHEAP_TYPE指向同一个对象
    CSingletonTest* pTesHEAP_TYPE = SingletonTesHEAP_TYPE::GetInstance();
    pTesHEAP_TYPE->AddCount();
    cout << "pTesHEAP_TYPE Count = " << pTesHEAP_TYPE->GetCount() << endl;

    // 2.多线程下测试 测试5000数据，加锁情况下5000， 不加锁不一定为5000
    CSingletonThreadTest<SingletonTesHEAP_TYPE> Test1("Test1");
    Test1.Start();
    CSingletonThreadTest<SingletonTesHEAP_TYPE> TesHEAP_TYPE("TesHEAP_TYPE");
    TesHEAP_TYPE.Start();
    CSingletonThreadTest<SingletonTesHEAP_TYPE> Test3("Test3");
    Test3.Start();
    CSingletonThreadTest<SingletonTesHEAP_TYPE> Test4("Test4");
    Test4.Start();
    CSingletonThreadTest<SingletonTesHEAP_TYPE> Test5("Test5");
    Test5.Start();

    CT_SLEEP(1);

    cout << "CSingleton_2TestFunc : " << SingletonTesHEAP_TYPE::GetInstance()->GetCount() << endl;
    cout << "花费时间: " << (clock() - dStart) / CONST_1000 << endl;

    cout << "\n\n --------------- CSingleton_2TestFunc End -------------->" << endl;

}

template <typename TYPE>
void SingletonTestFunc()
{
    //double dStart = clock();
    // 1.单线程测试
    TYPE::GetInstance()->AddCount();
    TYPE::GetInstance()->AddCount();
    cout << typeid(TYPE::GetInstance()).name() << ": Count = " << TYPE::GetInstance()->GetCount() << endl;

    CSingletonThreadTest<TYPE> Test1("Test1");
    Test1.Start();
    CSingletonThreadTest<TYPE> TesHEAP_TYPE("TesHEAP_TYPE");
    TesHEAP_TYPE.Start();
    CSingletonThreadTest<TYPE> Test3("Test3");
    Test3.Start();
    CSingletonThreadTest<TYPE> Test4("Test4");
    Test4.Start();
    CSingletonThreadTest<TYPE> Test5("Test5");
    Test5.Start();

    CT_SLEEP(10);

    cout << "SingletonTestFunc : " << TYPE::GetInstance()->GetCount() << endl;
    //cout << "花费时间: " << (clock() - dStart) / CONST_1000 << endl;
}

void SingletonPatternTestFunc()
{
    cout << "\n\n --------------- SingletonPatternTestFunc Start -------------->" << endl;
    
    //CSingleton_2TestFunc();

    SingletonTestFunc<SingletonTesHEAP_TYPE>();

    cout << "===================================================>>>" << endl;

    SingletonTestFunc<SingletonTest3>();

    cout << "===================================================>>>" << endl;
    SingletonTestFunc<SingletonTest4>();


    cout << "\n\n --------------- SingletonPatternTestFunc End -------------->" << endl;

}