c# 阻塞队列

　　/// <summary>

    /// 阻塞队列[.net 4.0 貌似自带了阻塞队列]

    /// </summary>

    public class BlockQueue<T>

    {

        public readonly int SizeLimit = 0;

        private Queue<T> _inner_queue = null;

        public int Count

        {

            get { return _inner_queue.Count; }

        }

        private ManualResetEvent _enqueue_wait = null;

        private ManualResetEvent _dequeue_wait = null;

        public BlockQueue(int sizeLimit)

        {

            this.SizeLimit = sizeLimit;

            this._inner_queue = new Queue<T>(this.SizeLimit);

            this._enqueue_wait = new ManualResetEvent(false);

            this._dequeue_wait = new ManualResetEvent(false);

        }

        public void EnQueue(T item)

        {

            if (this._IsShutdown == true) throw new InvalidCastException("Queue was shutdown. Enqueue was not allowed.");

            while (true)

            {

                lock (this._inner_queue)

                {

                    if (this._inner_queue.Count < this.SizeLimit)

                    {

                        this._inner_queue.Enqueue(item);

                        this._enqueue_wait.Reset();

                        this._dequeue_wait.Set();

                        break;

                    }

                }

                this._enqueue_wait.WaitOne();

            }

        }

        public T DeQueue()

        {

            while (true)

            {

                if (this._IsShutdown == true)

                {

                    lock (this._inner_queue) return this._inner_queue.Dequeue();

                }

                lock (this._inner_queue)

                {

                    if (this._inner_queue.Count > 0)

                    {

                        T item = this._inner_queue.Dequeue();

                        this._dequeue_wait.Reset();

                        this._enqueue_wait.Set();

                        return item;

                    }

                }

                this._dequeue_wait.WaitOne();

            }

        }

        private bool _IsShutdown = false;

        public void Shutdown()

        {

            this._IsShutdown = true;

            this._dequeue_wait.Set();

        }

    }