class MyClass : public WithMyClassLayout<TopWindow> 
{
public:
	typedef MyClass CLASSNAME;
	MyClass();
	void StartPlay();
	
	//thread handling
	volatile Atomic terminated;
	volatile Atomic threads;	
};

typedef struct {
	MyClass *gui;
} PlayInfo;

//thread callback
void WorkerThread(PlayInfo f)
{
    while (true)
    {
		if(f.gui->terminated)
			break;
		//playfile
		
    }
	AtomicDec(f.gui->threads);
}

//Callback of button
void MyClass::StartPlay()
{
	PlayInfo f;
	f.gui = this;
	AtomicInc(threads);
	Thread().Run(callback1(WorkerThread, f));//error in this line
}