using System;

using System.Threading.Tasks;

using System.Threading;                 

class Program

{

    static async Task Main(string[] args)

    {

        var counter = 0;

        var innerLoopToken = new CancellationTokenSource(TimeSpan.FromSeconds(5)).Token;

        var outerLoopToken = new CancellationTokenSource(TimeSpan.FromSeconds(10)).Token;

​

        while (true)

        {

            Console.WriteLine($"Outer Loop pre: {counter}");

​

            if(innerLoopToken.IsCancellationRequested)

            {

                Console.WriteLine($"The inner loop token was cancelled, so exiting outer loop");

                break;

            }

            await InnerLoopAsync(innerLoopToken);

​

            if(!innerLoopToken.IsCancellationRequested)

            {

                Console.WriteLine("I will never be called! Inner loop is still running, but the outer loop got control back!");

            }

            Console.WriteLine($"Outer Loop pst: {counter++}");

        }

​

        Console.WriteLine($"After cancelling inner and outer loops counter is at: '{counter}'. Which is not greater than 1. Which means outer loop was blocked until inner completed!");

    }

​

    static async Task InnerLoopAsync(CancellationToken token)

    {

        using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1));

        var counter = 0;

        while (await timer.WaitForNextTickAsync())

        {

            Console.WriteLine($"Inner Loop pre: {counter}");

            await DoSomeAsyncWork();

            Console.WriteLine($"Inner Loop post: {counter++}");

​

            if (token.IsCancellationRequested)

            {

                Console.WriteLine("Inner Loop stopping due to cancellation token");

                break;

            }

        }

    }

​

    static async Task DoSomeAsyncWork()

    {

        Console.WriteLine("Doing Some Async Work");

​

        await Task.Run(() => Task.Delay(1000));

​

        Console.WriteLine("Done doing Some Async Work!");

    }

}