NServiceBus - Watchdog that will execute a FailFast is no message processing happened for 5 minutes

WatchdogFeature.cs

sealed class WatchdogBehavior : Behavior<IIncomingLogicalMessageContext>, IDisposable
{
   static readonly TimeSpan watchdogTimeout = TimeSpan.FromMinutes(5);
   static volatile long lastActivityTicks = DateTime.UtcNow.Ticks;
   static Thread? watchdogThread;
   static CancellationTokenSource? cancellationTokenSource;

   public WatchdogBehavior()
   {
       StartWatchdog();
   }

   public override Task Invoke(IIncomingLogicalMessageContext context, Func<Task> next)
   {
       lastActivityTicks = DateTime.UtcNow.Ticks;
       return next();
   }

   static void StartWatchdog()
   {
       if (watchdogThread?.IsAlive == true) return;
       
       cancellationTokenSource = new CancellationTokenSource();
       watchdogThread = new Thread(() =>
       {
           var nextCheck = TimeSpan.FromSeconds(30);
           
           while (!cancellationTokenSource.Token.IsCancellationRequested)
           {
               var lastActivity = new DateTime(lastActivityTicks);
               var timeSinceActivity = DateTime.UtcNow - lastActivity;
               
               if (timeSinceActivity > watchdogTimeout)
               {
                   Environment.FailFast($"Message processing stalled. Last activity: {lastActivity:yyyy-MM-dd HH:mm:ss}");
               }
               
               nextCheck = timeSinceActivity < watchdogTimeout / 2 
                   ? TimeSpan.FromMinutes(1)  // Check less frequently when healthy
                   : TimeSpan.FromSeconds(15); // Check more frequently when approaching timeout
               
               Thread.Sleep(nextCheck);
           }
       })
       { IsBackground = false, Name = "NSB-Watchdog" };
       
       watchdogThread.Start();
   }

   public void Dispose()
   {
       cancellationTokenSource?.Cancel();
       cancellationTokenSource?.Dispose();
   }
}

sealed class WatchdogFeature : Feature
{
    protected override void Setup(FeatureConfigurationContext context)
    {
        context.RegisterStartupTask(new WatchdogStartupTask());
    }
}

sealed class WatchdogStartupTask : FeatureStartupTask, IDisposable
{
    WatchdogBehavior? watchdog;
    
    protected override Task OnStart(IMessageSession session, CancellationToken cancellationToken)
    {
        watchdog = new WatchdogBehavior();
        return Task.CompletedTask;
    }
    
    protected override Task OnStop(IMessageSession session, CancellationToken cancellationToken)
    {
        watchdog?.Dispose();
        return Task.CompletedTask;
    }
    
    public void Dispose() => watchdog?.Dispose(); // Is here just incase, but NServiceBus does not invoke dispose.
}