code: // from gee.cs.oswego.edu/home/jsr166/jsr166
  
  package jsr166tests.jtreg.util.Collection;
  
  /*
   * Copyright 2007 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 6529795
   * @summary next() does not change iterator state if throws NoSuchElementException
   * @author Martin Buchholz
   */
  
  import java.util.*;
  import java.util.concurrent.*;
  
  import edu.stanford.ppl.concurrent.SnapTreeMap;
  
  @SuppressWarnings("unchecked")
  public class IteratorAtEnd {
      private static final int SIZE = 6;
  
      static void realMain(String[] args) throws Throwable {
          testCollection(new ArrayList());
          testCollection(new Vector());
          testCollection(new LinkedList());
          testCollection(new ArrayDeque());
          testCollection(new TreeSet());
          testCollection(new CopyOnWriteArrayList());
          testCollection(new CopyOnWriteArraySet());
          testCollection(new ConcurrentSkipListSet());
  
          testCollection(new PriorityQueue());
          testCollection(new LinkedBlockingQueue());
          testCollection(new ArrayBlockingQueue(100));
          testCollection(new ConcurrentLinkedQueue());
          //testCollection(new LinkedTransferQueue());
  
          testMap(new HashMap());
          testMap(new Hashtable());
          testMap(new LinkedHashMap());
          testMap(new WeakHashMap());
          testMap(new IdentityHashMap());
          testMap(new ConcurrentHashMap());
          testMap(new ConcurrentSkipListMap());
          testMap(new SnapTreeMap());
          testMap(new TreeMap());
      }
  
      static void testCollection(Collection c) {
          try {
              for (int i = 0; i < SIZE; i++)
                  c.add(i);
              test(c);
          } catch (Throwable t) { unexpected(t); }
      }
  
      static void testMap(Map m) {
          try {
              for (int i = 0; i < 3*SIZE; i++)
                  m.put(i, i);
              test(m.values());
              test(m.keySet());
              test(m.entrySet());
          } catch (Throwable t) { unexpected(t); }
      }
  
      static void test(Collection c) {
          try {
              final Iterator it = c.iterator();
              THROWS(NoSuchElementException.class,
                     new Fun() {void f() { while (true) it.next(); }});
              try { it.remove(); }
              catch (UnsupportedOperationException _) { return; }
              pass();
          } catch (Throwable t) { unexpected(t); }
  
          if (c instanceof List) {
              final List list = (List) c;
              try {
                  final ListIterator it = list.listIterator(0);
                  it.next();
                  final Object x = it.previous();
                  THROWS(NoSuchElementException.class,
                         new Fun() {void f() { it.previous(); }});
                  try { it.remove(); }
                  catch (UnsupportedOperationException _) { return; }
                  pass();
                  check(! list.get(0).equals(x));
              } catch (Throwable t) { unexpected(t); }
  
              try {
                  final ListIterator it = list.listIterator(list.size());
                  it.previous();
                  final Object x = it.next();
                  THROWS(NoSuchElementException.class,
                         new Fun() {void f() { it.next(); }});
                  try { it.remove(); }
                  catch (UnsupportedOperationException _) { return; }
                  pass();
                  check(! list.get(list.size()-1).equals(x));
              } catch (Throwable t) { unexpected(t); }
          }
      }
  
      //--------------------- 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");}
      private static abstract class Fun {abstract void f() throws Throwable;}
      static void THROWS(Class<? extends Throwable> k, Fun... fs) {
          for (Fun f : fs)
              try { f.f(); fail("Expected " + k.getName() + " not thrown"); }
              catch (Throwable t) {
                  if (k.isAssignableFrom(t.getClass())) pass();
                  else unexpected(t);}}
  }
  