一个同步的例子

今天上操作系统的时，老师讲到进程同步提到售票系统，记得以前看孙鑫老师的视频时也提到过类似的东西。回来后马上动手，用C#实现了一个简单的进程同步。

 

using System;
using System.Threading;

public class ThreadCreat
{
    static int tickets = 100; //没有全局变量，静态变量也一样
    //为了使进程同步，需要一个监视器来阻止第二个线程进入一个受保护的代码段
    readonly static object _Sync = new object(); 
    public static void ThreadProc1()
    {

      //  Interlocked.Decrement(ref tickets); //这里不知道是什么，网上提供的方法，但是没用

        while (true)
        {  
            Monitor.Enter(_Sync);
                try
                {
                    if (tickets > 0)
                    {
                       Thread.Sleep(1);       
                       Console.WriteLine("thread 1 sell:titck leave {0} ", tickets--);        
                    }
                    else
                        break;
                }
                finally
                {
                    Monitor.Exit(_Sync);
                }
       }
    }

    public static void ThreadProc2()
    { 
        while (true)
        {
        //    Interlocked.Decrement(ref tickets);
              Monitor.Enter(_Sync);
            try
                {
                   if (tickets > 0)
                   {
                        Thread.Sleep(1);  
                        Console.WriteLine("thread 2 sell:titck leave {0} ", tickets--);
                   } 
                   else
                      break;
                } 
            finally
                {
                    Monitor.Exit(_Sync);
                }
              }
      }

    public static void Main()
    {
        //这里使用的是C#2.0的委托推断语法，不是显示地实例化ThreadStart
        Thread thread1 = new Thread(new ThreadStart(ThreadProc1));
        thread1.Start();

        Thread thread2 = new Thread(new ThreadStart(ThreadProc2));
        thread2.Start();

         //   Console.WriteLine("Main thread: do some work.");
        Thread.Sleep(4000);
        Console.ReadLine();
    }
    
}

累了，先睡觉。