volatile

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

namespace VolatileTest
{
    class Program
    {
        static void Main()
        {
            Test.TestVolatile();
        }
    }

    class Test
    {
        int foo;

        public static void TestVolatile()
        {
            var test = new Test();

            new Thread(delegate() { Thread.Sleep(500); test.foo = 255; }).Start();

            while (test.foo != 255) ;
            Console.WriteLine("OK");
        }
    }


}