Re: Synchronization when collecting data from the EDT?

Here's my (contrived) sscce. A javax.swing.Timer increments an int at
100 Hz, while a java.util.TimerTask samples the value at 1 Hz. I'd like
the API to be a little more explicit, but it does say that the calling
thread blocks and the Runnable's dispatch "will happen after all pending
events are processed."

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.reflect.InvocationTargetException;
import java.util.LinkedList;
import java.util.TimerTask;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;

/** @author John B. Matthews */
public class TwoTimer extends JPanel {

    private Timer timer = new Timer(10, null);
    private int value;

    public TwoTimer() {
        final JLabel label = new JLabel("0");
        timer.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                label.setText(String.valueOf(value++));
            }
        });
        this.add(label);
    }

    public int getValue() {
        return value;
    }

    public void startSwingTimer() {
        timer.start();
    }

    public void startUtilTimer() {
        final LinkedList<Integer> samples = new LinkedList<Integer>();
        java.util.Timer sampler = new java.util.Timer();
        sampler.scheduleAtFixedRate(new TimerTask() {

            @Override
            public void run() {
                try {
                    EventQueue.invokeAndWait(new Runnable() {

                        @Override
                        public void run() {
                            samples.add(getValue());
                        }
                    });
                } catch (InterruptedException ex) {
                    ex.printStackTrace(System.err);
                } catch (InvocationTargetException ex) {
                    ex.printStackTrace(System.err);
                }
                System.out.println(samples.getLast());
            }
        }, 1000, 1000);

    }

    private void display() {
        JFrame f = new JFrame("TwoTimer");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(this);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                TwoTimer tt = new TwoTimer();
                tt.display();
                tt.startSwingTimer();
                tt.startUtilTimer();
            }
        });
    }
}