// lowlevel/EvenProducer.java // (c)2017 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://OnJava8.com for more book information. // When threads collide public class EvenProducer extends IntGenerator { private int currentEvenValue = 0; @Override public int next() { ++currentEvenValue; // [1] ++currentEvenValue; return currentEvenValue; } public static void main(String[] args) { EvenChecker.test(new EvenProducer()); } } /* Output: 1563 not even! 1573 not even! 1571 not even! 1569 not even! 1567 not even! 1565 not even! */