#include "mainwindow.h"
    #include <QApplication>
    #include <QDebug>
    #include <QThread>
     
    class MyFirstThread : public QThread
    {
    private:
        void run()
        {
            while(1)
            {
                qDebug() << "MyFirstThread";
                sleep(2);
            }
        }
    };
     
    class MySecondThread : public QThread
    {
    private:
        void run()
        {
            while(1)
            {
                qDebug() << "MySecondThread";
                sleep(4);
            }
        }
    };
     
    int main(int argc, char *argv[])
    {
        QApplication a(argc, argv);
        MainWindow w;
        w.show();
     
        MyFirstThread t1;
        MySecondThread t2;
     
        t1.start();
        t2.start();
     
        return a.exec();
    }