using System;

using System.Threading;

using System.Threading.Tasks;

class Program

{

    static async Task Main(string[] args)

    {

        var source = new CancellationTokenSource();

        Console.WriteLine("Starting tasks...");

        var delayTask = Task.Delay(TimeSpan.FromSeconds(2));

        var workTask = SaySomethingAsync(10, source.Token);

        Console.WriteLine("Awaiting first task to complete...");

​

        await Task.WhenAny(delayTask, workTask);

​

        if (workTask.IsCompletedSuccessfully)

        {

            Console.WriteLine("Completed!");

            Console.WriteLine(workTask.Result);

        }

        else 

        {

            Console.WriteLine("Timed out :-(");

            source.Cancel();

        }

        Console.ReadKey();

    }

​

    static async Task<string> SaySomethingAsync(int secondsDelay, CancellationToken token)

    {

        var iterations = 0;

        while (iterations != secondsDelay)

        {

            if(token.IsCancellationRequested) 

            {

                break;

            }

            iterations++;

            Console.WriteLine($"....{iterations}");

            await Task.Delay(TimeSpan.FromSeconds(1));

        }

​

        return "Something!";

    }

}