一个C#多线程的工作队列

多线程添加元素到队列中,队列根据绑定

的事件进行自动处理,可以设置WorkSequential属性来实现对队列处理的单线程(严格顺序处理)或者多线程处理(循序出队,但是

多线程处理,不保证对队列元素的处理顺利)的选择。

另外,这段程序不能输出0,所以,最后的结果是999行,不包含0,原因是if (!item.Equals(default(T))),而default(T)恰恰是0.

代码

/***********多线程的工作队列***************
 * 此工作队列保证线程安全性
 * 
 * 
 * 
 * 
 * *******/
namespace WorkQueue
{
    using System.Collections.Generic;
    using System;
    using System.Threading;

    public delegate void UserWorkEventHandler<T>(object sender, WorkQueue<T>.EnqueueEventArgs e);
    public class WorkQueue<T>
    {
        private bool IsWorking; //表明处理线程是否正在工作
        private object lockIsWorking = new object();//对IsWorking的同步对象


        private Queue<T> queue; //实际的队列
        private object lockObj = new object(); //队列同步对象

       



        /// <summary>
        /// 绑定用户需要对队列中的item对象
        /// 施加的操作的事件
        /// </summary>
        public event UserWorkEventHandler<T> UserWork;

        public WorkQueue(int n)
        {
            queue = new Queue<T>(n);
        }

        public WorkQueue()
        {
            queue = new Queue<T>();
        }

        /// <summary>
        /// 谨慎使用此函数,
        /// 只保证此瞬间,队列值为空
        /// </summary>
        /// <returns></returns>
        public bool IsEmpty()
        {
            lock (lockObj)
            {
                return queue.Count == 0;
            }
        }

        private bool isOneThread;

        /// <summary>
        /// 队列处理是否需要单线程顺序执行
        /// ture表示单线程处理队列的T对象
        /// 默认为false,表明按照顺序出队,但是多线程处理item
        /// *****注意不要频繁改变此项****
        /// </summary>
        public bool WorkSequential
        {
            get
            {
                return isOneThread;
            }
            set
            {
                isOneThread = value;
            }

        }



        /// <summary>
        /// 向工作队列添加对象,
        /// 对象添加以后,如果已经绑定工作的事件
        /// 会触发事件处理程序,对item对象进行处理
        /// </summary>
        /// <param name="item">添加到队列的对象</param>
        public void EnqueueItem(T item)
        {
            lock (lockObj)
            {
                queue.Enqueue(item);
            }

            lock (lockIsWorking)
            {
                if (!IsWorking)
                {
                    IsWorking = true;
                    ThreadPool.QueueUserWorkItem(doUserWork);
                }
            }



        }


        /// <summary>
        /// 处理队列中对象的函数
        /// </summary>
        /// <param name="o"></param>
        private void doUserWork(object o)
        {
            try
            {
                T item;

                while (true)
                {
                    lock (lockObj)
                    {
                        if (queue.Count > 0)
                        {
                            item = queue.Dequeue();
                        }
                        else
                        {
                            return;
                        }
                    }
                    if (!item.Equals(default(T)))
                    {

                        if (isOneThread)
                        {
                            if (UserWork != null)
                            {
                                UserWork(this, new EnqueueEventArgs(item));
                            }
                        }
                        else
                        {
                            ThreadPool.QueueUserWorkItem(obj =>
                                                             {
                                                                 if (UserWork != null)
                                                                 {
                                                                     UserWork(this, new EnqueueEventArgs(obj));
                                                                 }
                                                             }, item);
                        }
                        

                    }

                }
            }
            finally
            {
                lock (lockIsWorking)
                {
                    IsWorking = false;
                }

            }
        }

        /// <summary>
        /// UserWork事件的参数,包含item对象
        /// </summary>
        public class EnqueueEventArgs : EventArgs
        {
            public T Item { get; private set; }
            public EnqueueEventArgs(object item)
            {
                try
                {
                    Item = (T)item;
                }
                catch (Exception)
                {

                    throw new InvalidCastException("object to T 转换失败");
                }
            }
        }
    }
}
代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.IO;
using WorkQueue;
namespace Program
{
    class Program
    {
        private static List<string> list=new List<string>(1000);
        static  StreamWriter sw = new StreamWriter(new FileStream("test.dat", FileMode.Create));
        static void Main(string[] args)
        {
            WorkQueue<int> workQueue=new WorkQueue<int>(1000);
            workQueue.UserWork += new UserWorkEventHandler<int>(workQueue_UserWork);
           // workQueue.WorkSequential = true;
            ThreadPool.QueueUserWorkItem(o =>
                                             {
                                                 for (int i = 0; i < 1000; i++)
                                                 {
                                                     workQueue.EnqueueItem(i);

                                                 }
                                             });
            Console.ReadLine();

            list.ForEach(str=>sw.WriteLine(str));
            Console.WriteLine(workQueue.IsEmpty());
            sw.Close();
        }

        static void workQueue_UserWork(object sender, WorkQueue<int>.EnqueueEventArgs e)
        {
           
            StringBuilder sb=new StringBuilder();
            sb.Append(e.Item).Append("		").Append(DateTime.Now.ToString("u")+"		").Append(Thread.CurrentThread.ManagedThreadId);
            list.Add(sb.ToString());
            Thread.Sleep(15);
        }
    }
}
原文地址:https://www.cnblogs.com/techfans/p/4111404.html