System Threading C# by API

using System;
using System.Threading;
public class TryEnter {
    public void CriticalSection() {
        bool b = Monitor.TryEnter(this, 1000);
        Console.WriteLine("Thread " +
                          Thread.CurrentThread.GetHashCode() +
                          " TryEnter Value " + b);
        for (int i = 1; i <= 3; i++) {
            Thread.Sleep(1000);
            Console.WriteLine(i + " " +
                              Thread.CurrentThread.GetHashCode() + " ");
        }
        Monitor.Exit(this);
    }
    public static void Main() {
        TryEnter a = new TryEnter();
        Thread t1 = new Thread(new ThreadStart(a.CriticalSection));
        Thread t2 = new Thread(new ThreadStart(a.CriticalSection));
        t1.Start();
        t2.Start();
    }
}