using System;

using System.Threading;

using System.Threading.Tasks;

public class Program

{

    public static void Main()

    {

        CancellationTokenSource source = new CancellationTokenSource(3000);

        Task worker = WaitForSomeOtherProcess(source.Token);

        Task sentinel = WaitForTimeout(source.Token);

        try

        {

            Task.WaitAll(worker, sentinel);

        }

        catch(OperationCanceledException oce)

        {

            Console.WriteLine(oce.CancellationToken.Equals(source.Token));

        }

        catch (AggregateException ae)

        {

            OperationCanceledException oce = ae.InnerException as OperationCanceledException;

            if (oce != null)

            {

                // THIS SHOULD PRINT TRUE...

                Console.WriteLine(oce.CancellationToken.Equals(source.Token));

            }

        }

    }

    public static async Task WaitForSomeOtherProcess(CancellationToken token)

    {

        CancellationTokenSource newSource = CancellationTokenSource.CreateLinkedTokenSource(token);

        while(true)

        {

            Console.WriteLine("Processing...");

            newSource.Token.ThrowIfCancellationRequested();

            await Task.Delay(1000);

        }

    }

    public static async Task WaitForTimeout(CancellationToken token)

    {

        while(true)

        {

            Console.WriteLine("Waiting for timeout...");

            token.ThrowIfCancellationRequested();

            await Task.Delay(1500);

        }

    }

}