Semaphore.WaitOne()
using System; using System.Threading; class MyThread { public Thread thrd; static Semaphore sem = new Semaphore(2, 2); public MyThread(string name) { thrd = new Thread(this.run); thrd.Name = name; thrd.Start(); } void run() { Console.WriteLine(thrd.Name + " is waiting for a permit."); sem.WaitOne(); Console.WriteLine(thrd.Name + " acquires a permit."); for(int i=0;i<10;i++) { Console.WriteLine(thrd.Name + " : " + i); Thread.Sleep(50); } Console.WriteLine(thrd.Name + " releases a permit."); sem.Release(); } } class MainClass { public static void Main() { MyThread mt1 = new MyThread("Thread #1"); MyThread mt2 = new MyThread("Thread #2"); MyThread mt3 = new MyThread("Thread #3"); mt1.thrd.Join(); mt2.thrd.Join(); mt3.thrd.Join(); } }