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[TestFixture]
	public class QueueTests
	{
		private IQueue q;
		private ManualResetEvent flag;

		[SetUp]
		public void Setup()
		{
			q = new ThreadSafeQueue();
			flag = new ManualResetEvent(false);
		}

		[TearDown]
		public void Teardown()
		{
			flag.Close();
		}

		[Test]
		public void EnqueueShouldWork()
		{
			q.Enqueue(new object());
		}

		[Test]
		public void DequeueAfterEnqueueShouldReturnTheSameObject()
		{
			object o = new object();

			q.Enqueue(o);
			Assert.AreEqual(o, q.Dequeue());
		}

		#region DequeueOnAnEmptyQueueShouldSleep
		[Test]
		public void DequeueOnAnEmptyQueueShouldSleep()
		{
			Thread t = new Thread(new ThreadStart(DequeueFromEmptyQueue));
			t.Start();

			flag.WaitOne(); // let other thread run
			Thread.Sleep(100);

			Assert.AreEqual(ThreadState.WaitSleepJoin, t.ThreadState);

			t.Abort(); // clean up
		}

		private void DequeueFromEmptyQueue()
		{
			flag.Set();
			q.Dequeue();
		}
		#endregion

		#region EnqueueShouldReleaseSleepingThread
		[Test]
		public void EnqueueShouldReleaseSleepingThread()
		{
			Thread t = new Thread(new ThreadStart(DequeueFromNonEmptyQueue));
			t.Start();

			flag.WaitOne(); // let other thread run
			Thread.Sleep(100);

			Assert.AreEqual(ThreadState.WaitSleepJoin, t.ThreadState);

			flag.Reset();

			q.Enqueue(1);

			flag.WaitOne(); // let other thread finish
			Thread.Sleep(100);

			Assert.IsTrue(true);
		}

		private void DequeueFromNonEmptyQueue()
		{
			flag.Set();
			object o = q.Dequeue();

			flag.Set();

			Assert.AreEqual(1, Convert.ToInt32(o));
		}
		#endregion

	}

public interface IQueue
	{
		void Enqueue(object o);
		object Dequeue();
	}

	/// 
	/// Summary description for ThreadSafeQueue.
	/// 
	public class ThreadSafeQueue: IQueue
	{
		private System.Collections.Queue q = new System.Collections.Queue();
		private ManualResetEvent newItemEntered = new ManualResetEvent(false);

		public Queue()
		{
		}

		public void Enqueue(object o)
		{
			lock(this)
			{
				q.Enqueue(o);
				newItemEntered.Set();
			}
		}

		public object Dequeue()
		{
			newItemEntered.WaitOne();

			lock(this)
			{
				object result = q.Dequeue();
				if (q.Count == 0)
					newItemEntered.Reset();

				return result;
			}

		}
	}