ComposingCancellationTokens.cs

using System;
using System.Threading;

namespace ConsoleApp1
{
    class Program
    {
        static void Main()
        {
            var worker = new Thread(Worker);
            using (var shutdown = new CancellationTokenSource())
            {
                worker.Start(shutdown.Token);
                Log("PARENT", "Press a key to cancel the 'shutdown' token");
                Console.ReadKey();
                Log("PARENT", "Cancelling the 'shutdown' token");
                shutdown.Cancel();
            }

            Log("PARENT", "Waiting for worker thread to finish");
            worker.Join();
            Log("PARENT", "Worker thread finished");

            Console.WriteLine("Press any key to exit");
            Console.ReadKey();
        }

        static void Worker(object param)
        {
            var cancellationTokenFromParent = (CancellationToken)param;

            using (var timerCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationTokenFromParent))
            {
                Log("WORKER", "Cancelling after 5 seconds");
                timerCts.CancelAfter(TimeSpan.FromSeconds(5));

                timerCts.Token.WaitHandle.WaitOne();
                Log("WORKER", "Cancellation requested");
                Log("WORKER", "Timer token:    IsCancellationRequested = {0}", timerCts.Token.IsCancellationRequested);
                Log("WORKER", "Shutdown token: IsCancellationRequested = {0}", cancellationTokenFromParent.IsCancellationRequested);
            }
        }

        static void Log(string source, string message, params object[] args)
        {
            Console.WriteLine($"[{DateTime.Now.ToString("hh:mm:ss.fff")}] {source.ToUpper()}: {message}", args);
        }
    }
}