Windows Service using Topshelf with Cancellable Task

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Topshelf;
using NLog;


namespace ListenerService
{
    class Program
    {
        static void Main(string[] args)
        {
            var rc = HostFactory.Run(x =>                                   //1
            {
                x.UseNLog();

                x.Service<QueueListener>(s =>                                   //2
                {
                    s.ConstructUsing(name => new QueueListener());                //3
                    s.WhenStarted(tc => tc.Start());                         //4
                    s.WhenStopped(tc => tc.Stop());                          //5
                });
                x.RunAsLocalSystem();                                       //6

                x.SetDescription("Queue Listener Daemon");                   //7
                x.SetDisplayName("Tobeadded");                                  //8
                x.SetServiceName("Tobeadded");                                  //9

                x.OnException(ex =>
                {
                    // Do something with the exception
                });
            });                                                             //10

            var exitCode = (int)Convert.ChangeType(rc, rc.GetTypeCode());  //11
            Environment.ExitCode = exitCode;
        }
    
    }
}

Queuelistener.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using NLog;

namespace ListenerService
{
    class QueueListener
    {
        private static readonly NLog.Logger Logger = NLog.LogManager.GetCurrentClassLogger();
        private readonly CancellationTokenSource tokenSource;
        private readonly CancellationToken ct;
        private Task processingTask;

        public QueueListener()
        {
            this.tokenSource  = new CancellationTokenSource();
            ct = this.tokenSource.Token;
        }
        public void Start()
        {
            processingTask = Task.Run(async () =>
            {
                // Were we already canceled?
                bool moreToDo = !ct.IsCancellationRequested;
                Logger.Info("Processing Started !!");
                try
                {
                    while (moreToDo)
                    {

                        ct.ThrowIfCancellationRequested();
                        // todo: Add code to dequeue from Queue with timeout
                        await Task.Delay(100).ConfigureAwait(false);                    

                        if (ct.IsCancellationRequested)
                        {
                            Logger.Info("Stop Signal Received!!");
                            moreToDo = false;
                        }
                    }
                } catch (OperationCanceledException ex)
                {
                    Logger.Error(ex, "Cancellation Requested");
                } finally
                {
                    // Todo: cleanup
                    Logger.Info("Cleaning up");
                }
            }, ct); // Pass same token to Task.Run.
        }

        public void Stop()
        {
            Logger.Info("Stop Requested!!");
            tokenSource.Cancel();
            if (processingTask != null)
            {
                Task.WaitAll(processingTask);
            }
        }
    }
}