// concurrency/SynchronizedEvenSupplier.java // Simplifying mutexes with the synchronized keyword. // {TimeOutDuringTesting} 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) { EvenChecker.test(new SynchronizedEvenSupplier()); } } /* Output: (None) */