TThread6.java

public class TThread6 {
    public static void main(String[] args) {
        Adder t = new Adder();
        t.start();
        (new TestSync(t)).start();
        t = null;
    }
}

class Adder extends Thread {
    private int count1 = 0, count2 = 0, count3 = 0;
    private boolean done = false;

public void run() {
        while (count1 <= 100) {
            count1++; count2++; count3++;
            try {
                Thread.sleep(50);
            } catch (InterruptedException e) {
                System.out.println("Application Interrupted");
            }
        }
        done = true;
    }

public boolean check() {
        int c1 = count1, c2 = count2, c3 = count3;
        if ((c1 != c2) || (c2 != c3)) {
            System.out.println("\rNot synced: " + c1 + ", " + c2 + ", " + c3);
        }
        return !done;
    }
}

class TestSync extends Thread {
    private int totAccess = 0;
    private Adder t1 = null;

public TestSync(Adder t) { t1 = t; }

public void run() {
        while (t1.check()) ++totAccess;
        System.out.println("Total sync accesses: " + totAccess);
    }
}