code: // from gee.cs.oswego.edu/home/jsr166/jsr166
  
  package jsr166tests.jtreg.util.concurrent.BlockingQueue;
  
  /*
   * 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 6215625
   * @summary Check correct behavior when last element is removed.
   * @author Martin Buchholz
   */
  
  import java.util.*;
  import java.util.concurrent.*;
  
  public class LastElement {
      void test(String[] args) throws Throwable {
          testQueue(new LinkedBlockingQueue<Integer>());
          testQueue(new LinkedBlockingDeque<Integer>());
          testQueue(new ArrayBlockingQueue<Integer>(10, true));
          testQueue(new ArrayBlockingQueue<Integer>(10, false));
          //testQueue(new LinkedTransferQueue<Integer>());
  
          System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
          if (failed > 0) throw new Exception("Some tests failed");
      }
  
      void testQueue(BlockingQueue<Integer> q) throws Throwable {
          Integer one = 1;
          Integer two = 2;
          Integer three = 3;
  
          // remove(Object)
          q.put(one);
          q.put(two);
          check(! q.isEmpty() && q.size() == 2);
          check(q.remove(one));
          check(q.remove(two));
          check(q.isEmpty() && q.size() == 0);
          q.put(three);
          try {check(q.take() == three);}
          catch (Throwable t) {unexpected(t);}
          check(q.isEmpty() && q.size() == 0);
  
          // iterator().remove()
          q.clear();
          q.put(one);
          check(q.offer(two));
          check(! q.isEmpty() && q.size() == 2);
          Iterator<Integer> i = q.iterator();
          check(i.next() == one);
          i.remove();
          check(i.next() == two);
          i.remove();
          check(q.isEmpty() && q.size() == 0);
          q.put(three);
          try {check(q.take() == three);}
          catch (Throwable t) {unexpected(t);}
          check(q.isEmpty() && q.size() == 0);
      }
  
      //--------------------- Infrastructure ---------------------------
      volatile int passed = 0, failed = 0;
      void pass() {passed++;}
      void fail() {failed++; Thread.dumpStack();}
      void fail(String msg) {System.err.println(msg); fail();}
      void unexpected(Throwable t) {failed++; t.printStackTrace();}
      void check(boolean cond) {if (cond) pass(); else fail();}
      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 {
          new LastElement().instanceMain(args);}
      public void instanceMain(String[] args) throws Throwable {
          try {test(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");}
  }
  