一段比較經典的多線程學習代碼。

1、用到了多線程的同步問題。
2、用到了多線程的順序問題。

如果有興趣的請仔細閱讀下面的代碼。注意其中代碼段的順序，思考一下，這些代碼的順序能否互相調換，為什么？這應該對學習很有幫助的。為了演示，讓所有的線程都Sleep了一段時間。

using System.Net;
using System;
using System.IO;
using System.Text;
using System.Threading;
using System.Diagnostics;

namespace Webb.Study
{
    class TestThread
    {
        static Mutex m_Mutex            = new Mutex();
        static Thread[] m_testThreads    = new Thread[10];
        static int m_threadIndex        = 0;

        static void ThreadCallBack()
        {
            TestThread.m_Mutex.WaitOne();
            int m_index    = m_threadIndex;
            TestThread.m_Mutex.ReleaseMutex();
            Console.WriteLine("Thread {0} start.",m_index);
            for(int i=0;i<=10;i++)
            {
                TestThread.m_Mutex.WaitOne();    
                Console.WriteLine("Thread {0}: is running. {1}",m_index,i);
                TestThread.m_Mutex.ReleaseMutex();
                Thread.Sleep(100);
            }
            Console.WriteLine("Thread {0} end.",m_index);
        }

        public static void Main(String[] args)
        {
            Console.WriteLine("Main thread start.");
            for(int i=0;i<TestThread.m_testThreads.Length;i++)
            {
                TestThread.m_threadIndex    = i;
                TestThread.m_testThreads[i]    = new Thread(new ThreadStart(ThreadCallBack));               
                TestThread.m_testThreads[i].Start();
                Thread.Sleep(100);
            }
            for(int i=0;i<TestThread.m_testThreads.Length;i++)
            {
                TestThread.m_testThreads[i].Join();
            }
            Console.WriteLine("Main thread exit.");
        }
    }
}
1、主函數中這兩句能否互換？為什么？
                TestThread.m_testThreads[i].Start();
                Thread.Sleep(100);

2、CallBack函數中這兩句能否互換？為什么？會有什么不同的結果？
                TestThread.m_Mutex.ReleaseMutex();
                Thread.Sleep(100);

3、主函數能否寫成這樣？為什么？會有什么不同的結果？
        public static void Main(String[] args)
        {
            Console.WriteLine("Main thread start.");
            for(int i=0;i<TestThread.m_testThreads.Length;i++)
            {
                TestThread.m_threadIndex    = i;
                TestThread.m_testThreads[i]    = new Thread(new ThreadStart(ThreadCallBack));               
                TestThread.m_testThreads[i].Start();
                TestThread.m_testThreads[i].Join();
                Thread.Sleep(100);
            }
            Console.WriteLine("Main thread exit.");
        }
4、這幾句的作用是什么？那么程序中還存在什么樣的問題？應該做怎樣的修改？
   TestThread.m_Mutex.WaitOne();
   int m_index = m_threadIndex;
   TestThread.m_Mutex.ReleaseMutex();

僅做學習討論。

http://wucountry.VEVb.com/archive/2006/06/19/429649.html