void Main()

{

    object obj1 = new object();

    object obj2 = new object();

    var t1 = new Thread(delegate(object p)

    {

        lock(obj1)

        {

            Thread.Sleep();

            lock(obj2)

            {

                Console.WriteLine("Thread1 executed.");

            }

        }

    });

    t1.Start();

    var t2 = new Thread(delegate(object p)

    {

        lock(obj2)

        {

            Thread.Sleep();

            lock(obj1)

            {

                Console.WriteLine("Thread2 executed.");

            }

        }

    });

    t2.Start();

    t1.Join();

    t2.Join();

    Console.WriteLine("over");

}