C# 多线程---------<一>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Collections;

namespace ConsoleApplication1
{
    //这是用来保存信息的数据结构，将作为参数被传递
    public class SomeState
    {
        public int Cookie;
        public SomeState(int iCookie)
        {
            Cookie = iCookie;
        }
    }

    public class Alpha
    {
        public Hashtable HashCount;
        public ManualResetEvent eventX;
        public static int iCount = 0;
        public static int iMaxCount = 0;

        public Alpha(int MaxCount)
        {
            HashCount = new Hashtable(MaxCount);
            iMaxCount = MaxCount;
        }

        //线程池里的线程将调用Beta()方法
        public void Beta(Object state)
        {
            //输出当前线程的hash编码值和Cookie的值
            Console.WriteLine(" {0} {1} :", Thread.CurrentThread.GetHashCode(), ((SomeState)state).Cookie);
            Console.WriteLine("HashCount.Count=={0}, Thread.CurrentThread.GetHashCode()=={1}", HashCount.Count, Thread.CurrentThread.GetHashCode());
            lock (HashCount)
            {
                //如果当前的Hash表中没有当前线程的Hash值，则添加之
                if (!HashCount.ContainsKey(Thread.CurrentThread.GetHashCode()))
                    HashCount.Add(Thread.CurrentThread.GetHashCode(), 0);
                HashCount[Thread.CurrentThread.GetHashCode()] =
                   ((int)HashCount[Thread.CurrentThread.GetHashCode()]) + 1;
            }
            int iX = 2000;
            Thread.Sleep(iX);
            //Interlocked.Increment()操作是一个原子操作，具体请看下面说明
            Interlocked.Increment(ref iCount);

            if (iCount == iMaxCount)
            {
                Console.WriteLine();
                Console.WriteLine("Setting eventX ");
                eventX.Set();
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Thread Pool Sample:");
            bool W2K = false;
            int MaxCount = 10;//允许线程池中运行最多10个线程
            
            //新建ManualResetEvent对象并且初始化为无信号状态
            ManualResetEvent eventX = new ManualResetEvent(false);
            
            Console.WriteLine("Queuing {0} items to Thread Pool", MaxCount);
            
            Alpha oAlpha = new Alpha(MaxCount);
            //创建工作项
            //注意初始化oAlpha对象的eventX属性
            oAlpha.eventX = eventX;
            Console.WriteLine("Queue to Thread Pool 0");
            
            try
            {
                //将工作项装入线程池 
                //这里要用到Windows 2000以上版本才有的API，所以可能出现NotSupportException异常
                ThreadPool.QueueUserWorkItem(new WaitCallback(oAlpha.Beta), new SomeState(0));
                W2K = true;
            }
            catch (NotSupportedException)
            {
                Console.WriteLine("These API's may fail when called on a non-Windows 2000 system.");
                W2K = false;
            }
            
            if (W2K)//如果当前系统支持ThreadPool的方法.
            {
                for (int iItem = 1; iItem < MaxCount; iItem++)
                {
                    //插入队列元素
                    Console.WriteLine("Queue to Thread Pool {0}", iItem);
                    ThreadPool.QueueUserWorkItem(new WaitCallback(oAlpha.Beta), new SomeState(iItem));
                }
                
                Console.WriteLine("Waiting for Thread Pool to drain");
                
                //等待事件的完成，即线程调用ManualResetEvent.Set()方法
                eventX.WaitOne(Timeout.Infinite, true);
                
                //WaitOne()方法使调用它的线程等待直到eventX.Set()方法被调用
                Console.WriteLine("Thread Pool has been drained (Event fired)");
                Console.WriteLine();
                Console.WriteLine("Load across threads");
                foreach (object o in oAlpha.HashCount.Keys)
                    Console.WriteLine("{0} {1}", o, oAlpha.HashCount[o]);
            }

            Console.ReadLine();
        }
    }
}