using Serilog;

using System;

using System.Diagnostics;

using System.Threading;

using System.Threading.Tasks;

​

class Program

{

    private const string _CLRF_ = "\r\n";

​

    private static ManualResetEvent _mre = new ManualResetEvent(true);

    private static CancellationTokenSource _cts;

​

    private static ConsoleKey _lastUserChoice;

​

    private static ILogger _logger;

​

    private static ILogger _consoleLogger = new LoggerConfiguration()

                .MinimumLevel.Information()

                .Enrich.FromLogContext()

                .Enrich.WithThreadId()

                .WriteTo.Console()

                .CreateLogger();

​

    private static ILogger _fileLogger = new LoggerConfiguration()

                .MinimumLevel.Information()

                .Enrich.FromLogContext()

                .Enrich.WithThreadId()

                .WriteTo.File("logs.txt")

                .CreateLogger();

​

    private static bool _firstRun = true;

​

    private static int _sideServiceLoopCounter = 0;

​

    static async Task Main(string[] args)

    {

        // setting global max clr threadpool threads to 2

        // just to demo what happens in high traffic where

        // you have only some threads available to work

        ThreadPool.SetMinThreads(1, 1);

        ThreadPool.SetMaxThreads(2, 2);

​

        while (_firstRun || UserKeyOn("Repeat this program (y/n) :") is ConsoleKey.Y)

        {

            _sideServiceLoopCounter = 0; // Reset the counter

            await Process();

            _firstRun = false;

        }

    }

​

    static async Task Process()

    {

        if (UserKeyOn("Choose your logger by typing (1) for console (2) for file :")

            is not

            (ConsoleKey.D1 or ConsoleKey.D2 or ConsoleKey.NumPad1 or ConsoleKey.NumPad2))

            return;

​

        if (_lastUserChoice is (ConsoleKey.D1 or ConsoleKey.NumPad1))

            _logger = _consoleLogger;

        else

            _logger = _fileLogger;

​

        _cts = new CancellationTokenSource();

        if (UserKeyOn("Start side service as well (y/n) :") is ConsoleKey.Y)

            StartSideServiceInThreadPool(_cts.Token);

​

        var sw = new Stopwatch();

        sw.Start();

​

        Prompt("Starting");

​

        _mre.Set();

        var tasks = new Task[100];

        for (int i = 0; i < 100; i++)

        {

            tasks[i] = Task.Run(() => LoopLog());

        }

​

        await Task.WhenAll(tasks);

​

        _mre.Reset();

        _cts.Cancel();

​

        sw.Stop();

​

        Prompt($"Done. It only took {sw.ElapsedMilliseconds} ms");

        Prompt($"SideService looped {_sideServiceLoopCounter} times");

    }

​

    static void LoopLog()

    {

        for (int i = 0; i < 100; i++)

        {

            _logger.Information("Bye bye threadpool. This is ThreadId: " + Thread.CurrentThread.ManagedThreadId);

        }

    }

​

    static void StartSideServiceInThreadPool(CancellationToken token)

    {

        ThreadPool.QueueUserWorkItem((state) =>

        {

            while (true)

            {

                if (token.IsCancellationRequested)

                    break;

                _mre.WaitOne();

​

                _logger.Information("This is a sidetask. This is ThreadId: " + Thread.CurrentThread.ManagedThreadId);

                Thread.Sleep(500);

​

                Interlocked.Increment(ref _sideServiceLoopCounter);

            }

        });

    }

​

    static ConsoleKey UserKeyOn(string message)

    {

        Prompt(message);

        return (_lastUserChoice = Console.ReadKey().Key);

    }

​

    static void Prompt(string message) =>

        Console.WriteLine($"{_CLRF_}{message}{_CLRF_}");

​

​

}