code: // from gee.cs.oswego.edu/home/jsr166/jsr166
  
  package jsr166tests.jtreg.util.concurrent.DelayQueue;
  
  /*
   * Copyright 2005 Sun Microsystems, Inc.  All Rights Reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
   * CA 95054 USA or visit www.sun.com if you need additional information or
   * have any questions.
   */
  
  /*
   * @test
   * @bug 6327342
   * @summary Try to poll a DelayQueue with only unexpired elements
   * @author Martin Buchholz
   */
  
  import java.util.concurrent.*;
  
  public class PollUnexpired {
      private static class Godot implements Delayed {
          public long getDelay(TimeUnit unit) {return Long.MAX_VALUE;}
          public int compareTo(Delayed other) {return 0;}
      }
  
      private static void realMain(String[] args) throws Throwable {
          DelayQueue<Godot> q = new DelayQueue<Godot>();
          for (int i = 0; i < 3; i++) {
              equal(q.size(), i);
              equal(q.poll(), null);
              equal(q.size(), i);
              equal(q.poll(100, TimeUnit.MILLISECONDS), null);
              equal(q.size(), i);
              q.add(new Godot());
          }
      }
  
      //--------------------- Infrastructure ---------------------------
      static volatile int passed = 0, failed = 0;
      static void pass() {passed++;}
      static void fail() {failed++; Thread.dumpStack();}
      static void fail(String msg) {System.out.println(msg); fail();}
      static void unexpected(Throwable t) {failed++; t.printStackTrace();}
      static void check(boolean cond) {if (cond) pass(); else fail();}
      static void equal(Object x, Object y) {
          if (x == null ? y == null : x.equals(y)) pass();
          else fail(x + " not equal to " + y);}
      public static void main(String[] args) throws Throwable {
          try {realMain(args);} catch (Throwable t) {unexpected(t);}
          System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
          if (failed > 0) throw new AssertionError("Some tests failed");}
  }
  