// threads/SynchronizedEvenSupplier.java // (c)2016 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://mindviewinc.com/Books/OnJava/ for more book information. // Simplifying mutexes with the synchronized keyword // {IgnoreOutput} // No output validation import onjava.TimedAbort; public class SynchronizedEvenSupplier extends IntSupplier { private int currentEvenValue = 0; @Override public synchronized int next() { ++currentEvenValue; Thread.yield(); // Cause failure faster ++currentEvenValue; return currentEvenValue; } public static void main(String[] args) { new TimedAbort(4); EvenChecker.test(new SynchronizedEvenSupplier()); } }