using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace CriticalSectionExample
{
    class Program
    {
        public static int x;
        public static int y;

        static void SwapXY()
        {
            int z = x;
            x = y;

            #region Some potentially time consuming operation
            for (int i = 0; i < int.MaxValue /40 ; i++)
                ;
            #endregion

            y = z;
        }

        static void Main(string[] args)
        {
            for (int i = 1; i < 10000; i++)
            {
                x = 1;
                y = 0;
                Thread one = new Thread(SwapXY);
                Thread two = new Thread(SwapXY);

                one.Start();
                two.Start();

                one.Join();
                two.Join();

                if (x != 1 || y != 0)
                {
                    Console.WriteLine("Incorrect swap on try {0}", i); 
                }
            }
        }
    }
}