using System;
using System.Runtime.InteropServices;
using System.Threading;

[StructLayout(LayoutKind.Sequential, Pack = 1)]
struct Hello
{
    byte padding1;
    public int value1;
    byte padding2;
    public int value2;
}

namespace Atomic
{
    public class Program
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Offset {0}", Marshal.OffsetOf<Hello>("value1"));
            Console.WriteLine("Offset {0}", Marshal.OffsetOf<Hello>("value2"));

            var hello = new Hello();

            var t1 = new Thread(() => {
                while (true)
                {
                    Thread.MemoryBarrier();
                    hello.value1 = 0;
                    hello.value2 = 0;
                }
            });
            t1.IsBackground = true;
            t1.Start();
            var t2 = new Thread(() => {
                while (true)
                {
                    Thread.MemoryBarrier();
                    hello.value1 = -1;
                    hello.value2 = -1;
                }
            });
            t2.Start();
            t2.IsBackground = true;

            int error_count = 0;

            while (true)
            {
                Thread.MemoryBarrier();
                var v1 = hello.value1;
                var v2 = hello.value2;

                if ((v1 != 0 && v1 != -1) || (v2 != 0 && v2 != -1))
                {
                    Console.WriteLine("{0} {1}", v1, v2);

                    error_count++;
                    if (error_count == 100)
                    {
                        break;
                    }
                }
            }
        }
    }
}