using System;

using System.Threading;

using System.Diagnostics;

​

public class Program

{

        class SomeClass

        {

            private object locker = new Object();

            public void SomeMethod(int id)

            {

                lock (locker)

                {

​

                    while (true)

                    {

                        Console.WriteLine("SomeClass.SomeMethod #" + id);

                        Thread.Sleep(500);

                    }

                }

            }

        }

    object obj = new Object();

​

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var p = new Program();

        p.Work();

    }

    public void Work(){

       SomeClass o = new SomeClass();

​

        lock(obj)

        {

            for (int threadId = 0; threadId < 3; threadId++)

            {

                Thread t = new Thread(() => {

                    o.SomeMethod(threadId);

                        });

                t.Start();

            }

​

            Console.WriteLine();

        }   

        var sw = Stopwatch.StartNew();

            while (sw.ElapsedMilliseconds < 8000)

            {

                Thread.Sleep(1);

            }

    }

​

}