简单消息队列

using System;

using System.Collections;

using System.Collections.Generic;

using System.Text;

namespace TestApplication

{

    /// <summary>

    /// 消息队列

    /// </summary>

    /// <typeparam name="T"></typeparam>

    public class MessageQueue<T>

    {

        private static object _lockObj = new object();

        private static MessageQueue<T> _instance;

        private Queue<T> _msgQueue;

        private MessageQueue()

        {

            this._msgQueue = new Queue<T>();

        }

        public static MessageQueue<T> CreateInstance()

        {

            if (_instance == null)

            {

                lock (_lockObj)

                {

                    if (_instance == null)

                    {

                        _instance = new MessageQueue<T>();                        

                    }

                }

            }

            return _instance;

        }

        public void PushMessage(T message)

        {

            lock (_lockObj)

            {

                if (_msgQueue.Contains(message))

                    return;

                _msgQueue.Enqueue(message);

            }

        }

        public bool IsEmpty()

        {

            return _msgQueue.Count < 1;

        }

        public T GetMessage()

        {

            lock (_lockObj)

            {

                if (_msgQueue.Count > 0)

                    return _msgQueue.Dequeue();

                else

                    return default(T);

            }

        }

        

    }

    public class MessagePump<T>

    {

        public Action<T> DoAction;

        private static object _lockObj = new object();

        private static MessagePump<T> _instance;

        public static MessagePump<T> CreateInstance()

        {

            if (_instance == null)

            {

                lock (_lockObj)

                {

                    if (_instance == null)

                    {

                        _instance = new MessagePump<T>();

                    }

                }

            }

            return _instance;

        }

        public MessageQueue<T> Messages { get; set; }

        public bool IsWorking { get; private set; }

        public void DoWork()

        {

            T empty = default(T);

            while (!Messages.IsEmpty())

            {

                IsWorking = true;

                var item = Messages.GetMessage();

                if (item.Equals(empty))

                {

                    break;

                }

                if (DoAction != null)

                    DoAction(item);

            }

            IsWorking = false;

        }

    }

}

调用

private void button1_Click(object sender, EventArgs e)
        {
            MessageQueue<int> messages = MessageQueue<int>.CreateInstance();
            MessagePump<int> pump = MessagePump<int>.CreateInstance();
            pump.Messages = messages;
            pump.DoAction = new Action<int>((item) =>
                {
                    this.Invoke(new Action(() =>
                        {
                            listBox1.Items.Add(item);
                        }));


                    // 模拟处理失败，重新入队
                    if (item % 2 == 0)
                    {
                        messages.PushMessage(item + 1);
                        if (!pump.IsWorking)
                            pump.DoWork();
                    }
                }
                );


            List<Thread> threads = new List<Thread>();
            for (var i = 1; i <= 10; i++)
            {
                int j = i;
                threads.Add(new Thread(() =>
                {                    
                    messages.PushMessage(j);
                    if (!pump.IsWorking)
                        pump.DoWork();
                }));
            }


            for(var i = 0; i < threads.Count; i++)
            {
                threads[i].Start();
            } 
        }