Code 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); } }