jpa/tests/org.eclipse.jpt.utility.tests/src/org/eclipse/jpt/utility/tests/internal/iterators/SynchronizedListIteratorTests.java - dali/webtools.dali - Git at Google

 /*******************************************************************************
  * Copyright (c) 2009 Oracle. All rights reserved.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0, which accompanies this distribution
  * and is available at http://www.eclipse.org/legal/epl-v10.html.
  *
  * Contributors:
  *     Oracle - initial API and implementation
  ******************************************************************************/
 package org.eclipse.jpt.utility.tests.internal.iterators;

 import java.util.Iterator;
 import java.util.ListIterator;
 import java.util.NoSuchElementException;

 import org.eclipse.jpt.utility.internal.iterators.SynchronizedListIterator;

 @SuppressWarnings("nls")
 public class SynchronizedListIteratorTests extends SynchronizedIteratorTests {

 	public SynchronizedListIteratorTests(String name) {
 		super(name);
 	}

 	public void testUnsynchronizedPrevious() throws Exception {
 		TestListIterator<String> iterator = this.buildNestedIterator();
 		iterator.next();
 		iterator.next();

 		PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
 		PreviousTestThread<String> thread2 = new PreviousTestThread<String>(iterator);
 		iterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// both threads should have read the same element from the iterator :-(
 		assertEquals("bar", thread1.previous);
 		assertEquals("bar", thread2.previous);
 	}

 	public void testSynchronizedPrevious() throws Exception {
 		TestListIterator<String> nestedIterator = this.buildNestedIterator();
 		ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
 		iterator.next();
 		iterator.next();

 		PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
 		PreviousTestThread<String> thread2 = new PreviousTestThread<String>(iterator);
 		nestedIterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// the threads should have read the correct elements from the iterator :-)
 		assertEquals("bar", thread1.previous);
 		assertEquals("foo", thread2.previous);
 	}

 	public void testUnsynchronizedHasPrevious() throws Exception {
 		TestListIterator<String> iterator = this.buildNestedIterator();
 		iterator.next();

 		PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
 		HasPreviousTestThread<String> thread2 = new HasPreviousTestThread<String>(iterator);
 		iterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// thread 1 will have the first element,
 		// but thread 2 will think there are more "previous" elements on the iterator :-(
 		assertEquals("foo", thread1.previous);
 		assertEquals(true, thread2.hasPrevious);
 	}

 	public void testSynchronizedHasPrevious() throws Exception {
 		TestListIterator<String> nestedIterator = this.buildNestedIterator();
 		ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
 		iterator.next();

 		PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
 		HasPreviousTestThread<String> thread2 = new HasPreviousTestThread<String>(iterator);
 		nestedIterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// thread 1 will have the first element,
 		// and thread 2 will think there are no more "previous" elements on the iterator :-)
 		assertEquals("foo", thread1.previous);
 		assertEquals(false, thread2.hasPrevious);
 	}

 	public void testUnsynchronizedNextIndex() throws Exception {
 		TestListIterator<String> iterator = this.buildNestedIterator();

 		NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
 		NextIndexTestThread<String> thread2 = new NextIndexTestThread<String>(iterator);
 		iterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// thread 1 will have the first element,
 		// but thread 2 will think the next index is still 0 :-(
 		assertEquals("foo", thread1.next);
 		assertEquals(0, thread2.nextIndex);
 	}

 	public void testSynchronizedNextIndex() throws Exception {
 		TestListIterator<String> nestedIterator = this.buildNestedIterator();
 		ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);

 		NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
 		NextIndexTestThread<String> thread2 = new NextIndexTestThread<String>(iterator);
 		nestedIterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// thread 1 will have the first element,
 		// and thread 2 will think the next index is 1 :-)
 		assertEquals("foo", thread1.next);
 		assertEquals(1, thread2.nextIndex);
 	}

 	public void testUnsynchronizedPreviousIndex() throws Exception {
 		TestListIterator<String> iterator = this.buildNestedIterator();
 		iterator.next();

 		PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
 		PreviousIndexTestThread<String> thread2 = new PreviousIndexTestThread<String>(iterator);
 		iterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// thread 1 will have the first element,
 		// but thread 2 will think the next index is still 0 :-(
 		assertEquals("foo", thread1.previous);
 		assertEquals(0, thread2.previousIndex);
 	}

 	public void testSynchronizedPreviousIndex() throws Exception {
 		TestListIterator<String> nestedIterator = this.buildNestedIterator();
 		ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
 		iterator.next();

 		PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
 		PreviousIndexTestThread<String> thread2 = new PreviousIndexTestThread<String>(iterator);
 		nestedIterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// thread 1 will have the first element,
 		// and thread 2 will think the next index is -1 :-)
 		assertEquals("foo", thread1.previous);
 		assertEquals(-1, thread2.previousIndex);
 	}

 	public void testUnsynchronizedSet() throws Exception {
 		TestListIterator<String> iterator = this.buildNestedIterator();
 		iterator.next();

 		NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
 		SetTestThread<String> thread2 = new SetTestThread<String>(iterator, "xxx");
 		iterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// the wrong element was set :-(
 		assertEquals("bar", thread1.next);
 		assertFalse(iterator.list.contains("foo"));
 		assertTrue(iterator.list.contains("xxx"));
 		assertTrue(iterator.list.contains("bar"));
 		assertTrue(iterator.list.contains("baz"));
 	}

 	public void testSynchronizedSet() throws Exception {
 		TestListIterator<String> nestedIterator = this.buildNestedIterator();
 		ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
 		iterator.next();

 		NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
 		SetTestThread<String> thread2 = new SetTestThread<String>(iterator, "xxx");
 		nestedIterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// the right element was set :-)
 		assertEquals("bar", thread1.next);
 		assertTrue(nestedIterator.list.contains("foo"));
 		assertFalse(nestedIterator.list.contains("bar"));
 		assertTrue(nestedIterator.list.contains("xxx"));
 		assertTrue(nestedIterator.list.contains("baz"));
 	}

 	public void testUnsynchronizedAdd() throws Exception {
 		TestListIterator<String> iterator = this.buildNestedIterator();
 		iterator.next();

 		NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
 		AddTestThread<String> thread2 = new AddTestThread<String>(iterator, "xxx");
 		iterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// the element was added at the wrong index :-(
 		assertEquals("bar", thread1.next);
 		assertTrue(iterator.list.contains("foo"));
 		assertEquals(0, iterator.list.indexOf("xxx"));
 		assertTrue(iterator.list.contains("xxx"));
 		assertTrue(iterator.list.contains("bar"));
 		assertTrue(iterator.list.contains("baz"));
 	}

 	public void testSynchronizedAdd() throws Exception {
 		TestListIterator<String> nestedIterator = this.buildNestedIterator();
 		ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
 		iterator.next();

 		NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
 		AddTestThread<String> thread2 = new AddTestThread<String>(iterator, "xxx");
 		nestedIterator.slowThread = thread1;

 		thread1.start();

 		// allow thread 1 to read the first element and get bogged down
 		sleep(100);
 		thread2.start();

 		// wait for the threads to finish
 		thread1.join();
 		thread2.join();

 		// the element was added at the correct index :-)
 		assertEquals("bar", thread1.next);
 		assertTrue(nestedIterator.list.contains("foo"));
 		assertEquals(1, nestedIterator.list.indexOf("xxx"));
 		assertTrue(nestedIterator.list.contains("xxx"));
 		assertTrue(nestedIterator.list.contains("bar"));
 		assertTrue(nestedIterator.list.contains("baz"));
 	}

 	@Override
 	ListIterator<String> buildSynchronizedIterator(Iterator<String> nestedIterator) {
 		return new SynchronizedListIterator<String>((ListIterator<String>) nestedIterator);
 	}

 	@Override
 	TestListIterator<String> buildNestedIterator() {
 		return new TestListIterator<String>(this.buildArray());
 	}

 	/**
 	 * previous thread
 	 */
 	class PreviousTestThread<E> extends Thread {
 		final ListIterator<E> iterator;
 		E previous;

 		PreviousTestThread(ListIterator<E> iterator) {
 			super();
 			this.iterator = iterator;
 		}

 		@Override
 		public void run() {
 			this.previous = this.iterator.previous();
 		}

 	}

 	/**
 	 * has previous thread
 	 */
 	class HasPreviousTestThread<E> extends Thread {
 		final ListIterator<E> iterator;
 		boolean hasPrevious;

 		HasPreviousTestThread(ListIterator<E> iterator) {
 			super();
 			this.iterator = iterator;
 		}

 		@Override
 		public void run() {
 			this.hasPrevious = this.iterator.hasPrevious();
 		}

 	}

 	/**
 	 * next index thread
 	 */
 	class NextIndexTestThread<E> extends Thread {
 		final ListIterator<E> iterator;
 		int nextIndex;

 		NextIndexTestThread(ListIterator<E> iterator) {
 			super();
 			this.iterator = iterator;
 		}

 		@Override
 		public void run() {
 			this.nextIndex = this.iterator.nextIndex();
 		}

 	}

 	/**
 	 * previous index thread
 	 */
 	class PreviousIndexTestThread<E> extends Thread {
 		final ListIterator<E> iterator;
 		int previousIndex;

 		PreviousIndexTestThread(ListIterator<E> iterator) {
 			super();
 			this.iterator = iterator;
 		}

 		@Override
 		public void run() {
 			this.previousIndex = this.iterator.previousIndex();
 		}

 	}

 	/**
 	 * set thread
 	 */
 	class SetTestThread<E> extends Thread {
 		final ListIterator<E> iterator;
 		final E element;

 		SetTestThread(ListIterator<E> iterator, E element) {
 			super();
 			this.iterator = iterator;
 			this.element = element;
 		}

 		@Override
 		public void run() {
 			this.iterator.set(this.element);
 		}

 	}

 	/**
 	 * add thread
 	 */
 	class AddTestThread<E> extends Thread {
 		final ListIterator<E> iterator;
 		final E element;

 		AddTestThread(ListIterator<E> iterator, E element) {
 			super();
 			this.iterator = iterator;
 			this.element = element;
 		}

 		@Override
 		public void run() {
 			this.iterator.add(this.element);
 		}

 	}

 	/**
 	 * test list iterator
 	 */
 	class TestListIterator<E> extends TestIterator<E> implements ListIterator<E> {

 		TestListIterator(E... array) {
 			super(array);
 		}

 		public int nextIndex() {
 			return this.nextIndex;
 		}

 		public boolean hasPrevious() {
 			return this.nextIndex != 0;
 		}

 		public E previous() {
 			if (this.hasPrevious()) {
 				E previous = this.list.get(this.previousIndex());
 				sleep();
 				this.nextIndex--;
 				this.lastIndex = this.nextIndex;
 				return previous;
 			}
 			throw new NoSuchElementException();
 		}

 		public int previousIndex() {
 			return this.nextIndex - 1;
 		}

 		public void set(E e) {
 			if (this.lastIndex == -1) {
 				throw new IllegalStateException();
 			}
 			this.list.set(this.lastIndex, e);
 		}

 		public void add(E e) {
 			this.list.add(this.lastIndex, e);
 			this.lastIndex++;
 			this.lastIndex = -1;
 		}

 	}

 }
	/*******************************************************************************
	* Copyright (c) 2009 Oracle. All rights reserved.
	* This program and the accompanying materials are made available under the
	* terms of the Eclipse Public License v1.0, which accompanies this distribution
	* and is available at http://www.eclipse.org/legal/epl-v10.html.
	*
	* Contributors:
	* Oracle - initial API and implementation
	******************************************************************************/
	package org.eclipse.jpt.utility.tests.internal.iterators;

	import java.util.Iterator;
	import java.util.ListIterator;
	import java.util.NoSuchElementException;

	import org.eclipse.jpt.utility.internal.iterators.SynchronizedListIterator;

	@SuppressWarnings("nls")
	public class SynchronizedListIteratorTests extends SynchronizedIteratorTests {

	public SynchronizedListIteratorTests(String name) {
	super(name);
	}

	public void testUnsynchronizedPrevious() throws Exception {
	TestListIterator<String> iterator = this.buildNestedIterator();
	iterator.next();
	iterator.next();

	PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
	PreviousTestThread<String> thread2 = new PreviousTestThread<String>(iterator);
	iterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// both threads should have read the same element from the iterator :-(
	assertEquals("bar", thread1.previous);
	assertEquals("bar", thread2.previous);
	}

	public void testSynchronizedPrevious() throws Exception {
	TestListIterator<String> nestedIterator = this.buildNestedIterator();
	ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
	iterator.next();
	iterator.next();

	PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
	PreviousTestThread<String> thread2 = new PreviousTestThread<String>(iterator);
	nestedIterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// the threads should have read the correct elements from the iterator :-)
	assertEquals("bar", thread1.previous);
	assertEquals("foo", thread2.previous);
	}

	public void testUnsynchronizedHasPrevious() throws Exception {
	TestListIterator<String> iterator = this.buildNestedIterator();
	iterator.next();

	PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
	HasPreviousTestThread<String> thread2 = new HasPreviousTestThread<String>(iterator);
	iterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// thread 1 will have the first element,
	// but thread 2 will think there are more "previous" elements on the iterator :-(
	assertEquals("foo", thread1.previous);
	assertEquals(true, thread2.hasPrevious);
	}

	public void testSynchronizedHasPrevious() throws Exception {
	TestListIterator<String> nestedIterator = this.buildNestedIterator();
	ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
	iterator.next();

	PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
	HasPreviousTestThread<String> thread2 = new HasPreviousTestThread<String>(iterator);
	nestedIterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// thread 1 will have the first element,
	// and thread 2 will think there are no more "previous" elements on the iterator :-)
	assertEquals("foo", thread1.previous);
	assertEquals(false, thread2.hasPrevious);
	}

	public void testUnsynchronizedNextIndex() throws Exception {
	TestListIterator<String> iterator = this.buildNestedIterator();

	NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
	NextIndexTestThread<String> thread2 = new NextIndexTestThread<String>(iterator);
	iterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// thread 1 will have the first element,
	// but thread 2 will think the next index is still 0 :-(
	assertEquals("foo", thread1.next);
	assertEquals(0, thread2.nextIndex);
	}

	public void testSynchronizedNextIndex() throws Exception {
	TestListIterator<String> nestedIterator = this.buildNestedIterator();
	ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);

	NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
	NextIndexTestThread<String> thread2 = new NextIndexTestThread<String>(iterator);
	nestedIterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// thread 1 will have the first element,
	// and thread 2 will think the next index is 1 :-)
	assertEquals("foo", thread1.next);
	assertEquals(1, thread2.nextIndex);
	}

	public void testUnsynchronizedPreviousIndex() throws Exception {
	TestListIterator<String> iterator = this.buildNestedIterator();
	iterator.next();

	PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
	PreviousIndexTestThread<String> thread2 = new PreviousIndexTestThread<String>(iterator);
	iterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// thread 1 will have the first element,
	// but thread 2 will think the next index is still 0 :-(
	assertEquals("foo", thread1.previous);
	assertEquals(0, thread2.previousIndex);
	}

	public void testSynchronizedPreviousIndex() throws Exception {
	TestListIterator<String> nestedIterator = this.buildNestedIterator();
	ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
	iterator.next();

	PreviousTestThread<String> thread1 = new PreviousTestThread<String>(iterator);
	PreviousIndexTestThread<String> thread2 = new PreviousIndexTestThread<String>(iterator);
	nestedIterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// thread 1 will have the first element,
	// and thread 2 will think the next index is -1 :-)
	assertEquals("foo", thread1.previous);
	assertEquals(-1, thread2.previousIndex);
	}

	public void testUnsynchronizedSet() throws Exception {
	TestListIterator<String> iterator = this.buildNestedIterator();
	iterator.next();

	NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
	SetTestThread<String> thread2 = new SetTestThread<String>(iterator, "xxx");
	iterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// the wrong element was set :-(
	assertEquals("bar", thread1.next);
	assertFalse(iterator.list.contains("foo"));
	assertTrue(iterator.list.contains("xxx"));
	assertTrue(iterator.list.contains("bar"));
	assertTrue(iterator.list.contains("baz"));
	}

	public void testSynchronizedSet() throws Exception {
	TestListIterator<String> nestedIterator = this.buildNestedIterator();
	ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
	iterator.next();

	NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
	SetTestThread<String> thread2 = new SetTestThread<String>(iterator, "xxx");
	nestedIterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// the right element was set :-)
	assertEquals("bar", thread1.next);
	assertTrue(nestedIterator.list.contains("foo"));
	assertFalse(nestedIterator.list.contains("bar"));
	assertTrue(nestedIterator.list.contains("xxx"));
	assertTrue(nestedIterator.list.contains("baz"));
	}

	public void testUnsynchronizedAdd() throws Exception {
	TestListIterator<String> iterator = this.buildNestedIterator();
	iterator.next();

	NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
	AddTestThread<String> thread2 = new AddTestThread<String>(iterator, "xxx");
	iterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// the element was added at the wrong index :-(
	assertEquals("bar", thread1.next);
	assertTrue(iterator.list.contains("foo"));
	assertEquals(0, iterator.list.indexOf("xxx"));
	assertTrue(iterator.list.contains("xxx"));
	assertTrue(iterator.list.contains("bar"));
	assertTrue(iterator.list.contains("baz"));
	}

	public void testSynchronizedAdd() throws Exception {
	TestListIterator<String> nestedIterator = this.buildNestedIterator();
	ListIterator<String> iterator = this.buildSynchronizedIterator(nestedIterator);
	iterator.next();

	NextTestThread<String> thread1 = new NextTestThread<String>(iterator);
	AddTestThread<String> thread2 = new AddTestThread<String>(iterator, "xxx");
	nestedIterator.slowThread = thread1;

	thread1.start();

	// allow thread 1 to read the first element and get bogged down
	sleep(100);
	thread2.start();

	// wait for the threads to finish
	thread1.join();
	thread2.join();

	// the element was added at the correct index :-)
	assertEquals("bar", thread1.next);
	assertTrue(nestedIterator.list.contains("foo"));
	assertEquals(1, nestedIterator.list.indexOf("xxx"));
	assertTrue(nestedIterator.list.contains("xxx"));
	assertTrue(nestedIterator.list.contains("bar"));
	assertTrue(nestedIterator.list.contains("baz"));
	}

	@Override
	ListIterator<String> buildSynchronizedIterator(Iterator<String> nestedIterator) {
	return new SynchronizedListIterator<String>((ListIterator<String>) nestedIterator);
	}

	@Override
	TestListIterator<String> buildNestedIterator() {
	return new TestListIterator<String>(this.buildArray());
	}

	/**
	* previous thread
	*/
	class PreviousTestThread<E> extends Thread {
	final ListIterator<E> iterator;
	E previous;

	PreviousTestThread(ListIterator<E> iterator) {
	super();
	this.iterator = iterator;
	}

	@Override
	public void run() {
	this.previous = this.iterator.previous();
	}

	}

	/**
	* has previous thread
	*/
	class HasPreviousTestThread<E> extends Thread {
	final ListIterator<E> iterator;
	boolean hasPrevious;

	HasPreviousTestThread(ListIterator<E> iterator) {
	super();
	this.iterator = iterator;
	}

	@Override
	public void run() {
	this.hasPrevious = this.iterator.hasPrevious();
	}

	}

	/**
	* next index thread
	*/
	class NextIndexTestThread<E> extends Thread {
	final ListIterator<E> iterator;
	int nextIndex;

	NextIndexTestThread(ListIterator<E> iterator) {
	super();
	this.iterator = iterator;
	}

	@Override
	public void run() {
	this.nextIndex = this.iterator.nextIndex();
	}

	}

	/**
	* previous index thread
	*/
	class PreviousIndexTestThread<E> extends Thread {
	final ListIterator<E> iterator;
	int previousIndex;

	PreviousIndexTestThread(ListIterator<E> iterator) {
	super();
	this.iterator = iterator;
	}

	@Override
	public void run() {
	this.previousIndex = this.iterator.previousIndex();
	}

	}

	/**
	* set thread
	*/
	class SetTestThread<E> extends Thread {
	final ListIterator<E> iterator;
	final E element;

	SetTestThread(ListIterator<E> iterator, E element) {
	super();
	this.iterator = iterator;
	this.element = element;
	}

	@Override
	public void run() {
	this.iterator.set(this.element);
	}

	}

	/**
	* add thread
	*/
	class AddTestThread<E> extends Thread {
	final ListIterator<E> iterator;
	final E element;

	AddTestThread(ListIterator<E> iterator, E element) {
	super();
	this.iterator = iterator;
	this.element = element;
	}

	@Override
	public void run() {
	this.iterator.add(this.element);
	}

	}

	/**
	* test list iterator
	*/
	class TestListIterator<E> extends TestIterator<E> implements ListIterator<E> {

	TestListIterator(E... array) {
	super(array);
	}

	public int nextIndex() {
	return this.nextIndex;
	}

	public boolean hasPrevious() {
	return this.nextIndex != 0;
	}

	public E previous() {
	if (this.hasPrevious()) {
	E previous = this.list.get(this.previousIndex());
	sleep();
	this.nextIndex--;
	this.lastIndex = this.nextIndex;
	return previous;
	}
	throw new NoSuchElementException();
	}

	public int previousIndex() {
	return this.nextIndex - 1;
	}

	public void set(E e) {
	if (this.lastIndex == -1) {
	throw new IllegalStateException();
	}
	this.list.set(this.lastIndex, e);
	}

	public void add(E e) {
	this.list.add(this.lastIndex, e);
	this.lastIndex++;
	this.lastIndex = -1;
	}

	}

	}