The following minimized sample deadlocks

import java.awt.*;

public class Dispose {
    public static void main(String[] args) {
        Frame frame = new Frame();
        frame.setSize(100, 100);
        frame.setVisible(true);
        synchronized (frame.getTreeLock()) {
             frame.dispose();
        }
    }
}

If user calls dispose from some awt method which holds TreeLock it
causes deadlock even if the user code doesn't get TreeLock itself.