#ifndef DTKSINGLETON_H
#define DTKSINGLETON_H

#include <QtCore/QMutex>

template <class T> class dtkSingleton
{
public:
    static T& instance(void) {
        static QMutex mutex;

        if (!s_instance) {

            mutex.lock();

            if (!s_instance)
                s_instance = new T;

            mutex.unlock();
        }

        return (*s_instance);
    }

private:
    dtkSingleton(void) {};
    ~dtkSingleton(void) {};

private:
    Q_DISABLE_COPY(dtkSingleton)

private:
    static T *s_instance;
};

template <class T> T *dtkSingleton<T>::s_instance = NULL;

#define DTK_IMPLEMENT_SINGLETON(T)              \
    T *T::instance()                            \
    {                                           \
        return &(dtkSingleton<T>::instance());  \
    }

#endif //DTKSINGLETON