Singleton

class Singleton
{
public:
    ~Singleton();
    static Singleton* GetInstance();

private:
    Singleton();
    static Singleton* m_pInstance;
    static pthread_mutex_t s_initLock;

    class Deletor
    {
    public:
        ~Deletor()
        {
            if (Singleton::m_pInstance)
            {
                delete Singleton::m_pInstance;
                Singleton::m_pInstance = NULL;
            }
        }
    };
    static Deletor s_deletor;
};



Singleton* Singleton::m_pInstance;
pthread_mutex_t Singleton::s_initLock = PTHREAD_MUTEX_INITIALIZER;
Singleton::Deletor Singleton::s_deletor;


Singleton::Singleton()
{
}

Singleton::~Singleton()
{
}


Singleton* Singleton::GetInstance()
{
    if (!m_pInstance)
    {
        pthread_mutex_lock(&s_initLock);
        if (!m_pInstance)
        {
            m_pInstance = new Singleton;
        }
        pthread_mutex_unlock(&s_initLock);
    }

    return m_pInstance;
}