1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading;
 6  
 7 namespace MutiThread
 8 {
 9     /// <summary>
10     /// .net 信号量Semaphore的使用
11     /// </summary>
12     class Program
13     {
14         static void Main(string[] args)
15         {
16             //初始化4个线程
17             Mythread mythrd1 = new Mythread("Thrd #1");
18             Mythread mythrd2 = new Mythread("Thrd #2");
19             Mythread mythrd3 = new Mythread("Thrd #3");
20             Mythread mythrd4 = new Mythread("Thrd #4");
21  
22             //Join()方法阻塞调用线程 
23             //达到主线程在4个子线程执行完毕才退出的目的
24             mythrd1.thrd.Join();
25             mythrd2.thrd.Join();
26             mythrd3.thrd.Join();
27             mythrd4.thrd.Join();
28  
29         }
30     }
31  
32     /// <summary>
33     /// 封装线程类
34     /// </summary>
35     class Mythread
36     {
37         public Thread thrd;
38         //创建一个可授权2个许可证的信号量，且初始值为2
39         static Semaphore sem = new Semaphore(2, 2);
40  
41         public Mythread(string name)
42         {
43             thrd = new Thread(this.run);
44             thrd.Name = name;
45             thrd.Start();
46         }
47  
48         void run()
49         {
50             Console.WriteLine(thrd.Name + "正在等待一个许可证……");
51             //申请一个许可证
52             sem.WaitOne();
53             Console.WriteLine(thrd.Name + "申请到许可证……");
54             for (int i = 0; i < 4; i++)
55             {
56                 Console.WriteLine(thrd.Name + "： " + i);
57                 Thread.Sleep(1000);
58             }
59             Console.WriteLine(thrd.Name + " 释放许可证……");
60             //释放许可证
61             sem.Release();
62         }
63     }
64  
65 }