dev/vala/threads/class.vala

public class MyThread : Object {

	private string _s;

	public MyThread (string s) {
		_s = s;
	}

	public int run () {
		stdout.printf ("%s\n", _s);
		//Thread.usleep(3000000);
		return 0;
		//Thread.exit (0); // the same
	}
}

void main () {
	var mt = new MyThread ("This is my thread is running!\n");
	var t = new Thread<int> ("Debugging thread name", mt.run);
	t.join ();
}