using System;

using System.Threading;

using System.Threading.Tasks;

public class Program

{

    public static async Task Main()

    {

        var cts = new CancellationTokenSource();

​

        var task = Task.Run(async () =>

        {

            try

            {

                await Task.Delay(TimeSpan.FromSeconds(30), cts.Token);

            }

            catch (TaskCanceledException) { }

            Thread.Sleep(TimeSpan.FromSeconds(3)); // output 1 2

            //await Task.Delay(TimeSpan.FromSeconds(3)); // outputs 2 1

            Console.WriteLine("1");

        });

​

        Thread.Sleep(TimeSpan.FromSeconds(3));

​

        cts.Cancel();

        Console.WriteLine("2");

​

        await task;

    }

}