using System;

using System.Threading;

using System.Threading.Tasks;

using System.Linq;

using System.Runtime.CompilerServices;

​

public static class Program

{

    public static void Main()

    {

        ThreadSafeData<(int, int, int, int, int, int, int, int, int)> data = new();

        data.Init();

        using CancellationTokenSource cts = new(1000);

        int writerSpinCount = 0;

        int readerSpinCount = 0;

        int readersCount = 4;

        Task<int> writer = new Task<int>(() =>

        {

            int iterations = 0;

            Random random = new();

            while (!cts.IsCancellationRequested)

            {

                iterations++;

                int value = random.Next();

                data.SetData((value, value, value, value, value, value, value, value, value));

                Thread.SpinWait(writerSpinCount);

            }

            return iterations;

        });

        Task<(int, int)>[] readers = Enumerable.Range(1, readersCount).Select(n => new Task<(int, int)>(() =>

        {

            int iterations = 0;

            int tornValues = 0;

            while (!cts.IsCancellationRequested)

            {

                iterations++;

                var d = data.GetData();

                if (d.Item1 != d.Item2 || d.Item1 != d.Item3 || d.Item1 != d.Item4 || d.Item1 != d.Item5 || d.Item1 != d.Item6 || d.Item1 != d.Item7 || d.Item1 != d.Item8 || d.Item1 != d.Item9)

                {

                    tornValues++;

                    if (tornValues == 1) Console.WriteLine($"Reader #{n}, First torn value: {d}");

                }

                Thread.SpinWait(readerSpinCount);

            }

            return (iterations, tornValues);

        })).ToArray();

        Console.WriteLine($"Type: {data.GetType().Name}, Tuple.Length: {((ITuple)data.GetData()).Length:#,0}");

        Console.WriteLine($"Writer (1) SpinCount: {writerSpinCount:#,0}");

        Console.WriteLine($"Reader ({readers.Length}) SpinCount: {readerSpinCount:#,0}");

        Console.WriteLine();

        ThreadPool.SetMinThreads(readers.Length + 1, 4);

        Task allTasks = Task.WhenAll(readers.Cast<Task>().Prepend(writer).ToArray());

        long mem0 = GC.GetTotalAllocatedBytes(true);

        Array.ForEach(readers, r => r.Start(TaskScheduler.Default));

        writer.RunSynchronously(TaskScheduler.Default);

        allTasks.Wait();

        long mem1 = GC.GetTotalAllocatedBytes(true);

        Console.WriteLine($"Writer iterations: {writer.Result:#,0}");

        Console.WriteLine($"Reader iterations: {String.Join(", ", readers.Select(r => $"{r.Result.Item1:#,0}"))} (Sum: {readers.Select(r => r.Result.Item1).Sum():#,0})");

        int sumTornValues = readers.Select(r => r.Result.Item2).Sum();

        if (sumTornValues > 0) Console.WriteLine($"Torn values: {String.Join(", ", readers.Select(r => $"{r.Result.Item2:#,0}"))} (Sum: {sumTornValues:#,0})");

        Console.WriteLine($"Allocated: {mem1 - mem0:#,0} bytes");

    }

​

    public struct ThreadSafeData<T>

    {

        private T[] dataArray;

​

        private int setterIndex;        

        private int lastSetIndex;

​

        public void Init()

        {

            dataArray = new T[2];

        }

​

        public void SetData(T data)

        {

            dataArray[setterIndex] = data;            

            lastSetIndex = setterIndex;

​

            // Convert 0 to 1, and 1 to 0

            setterIndex = lastSetIndex * - 1 + 1;

        }

​

        public T GetData()

        {            

            return dataArray[lastSetIndex];

        }

    }

}

​