using System;

using System.Threading;

using System.Threading.Tasks;

​

namespace Test;

​

internal class Bar

{

    public SemaphoreSlim sm = new SemaphoreSlim(1, 1);

​

    public async Task RunMe()

    {

        Console.WriteLine("RunMe++, " + Thread.CurrentThread.ManagedThreadId);

        await sm.WaitAsync();

        await Task.Run(() => { });

        await RunMe();

        sm.Release();

        Console.WriteLine("RunMe--" + Thread.CurrentThread.ManagedThreadId);

    }

}

​

internal class MainApp

{

    public static void Main()

    {

        Bar b = new Bar();

        b.RunMe().Wait();

        Console.WriteLine("Done");

    }

}