using System;

using System.Threading;

​

public class LockStatement 

{ 

    static CountdownEvent _countdown = new CountdownEvent (3);

    public static void Main()

    {   

        new Thread (SaySomething).Start ("I am thread 1");

        new Thread (SaySomething).Start ("I am thread 2");

        new Thread (SaySomething).Start ("I am thread 3");

        _countdown.Wait(); // Blocks until Signal has been called 3 times

        Console.WriteLine ("All threads have finished speaking!"); 

    }

    static void SaySomething (object thing)

    {

        Thread.Sleep(1000);

        Console.WriteLine (thing);

        _countdown.Signal();

    } 

}