How to properly stop a multi-threaded .NET windows service?

Question

I have a windows service written in C# that creates a truck load of threads and makes many network connections (WMI, SNMP, simple TCP, http). When attempting to stop the win

Answer 1

Matt Davis is pretty complete.
A few points; If you have a thread that runs forever (because it has has a near-infinite loop and a catch all) and your service 's job is to run that thread, you probably want it to be a foreground thread.

Also, if any of your tasks are performing a longer operation such as a sproc call and so your Join timeout needs to be a little longer, you can actually asked the SCM for more time to shut down. See: https://msdn.microsoft.com/en-us/library/system.serviceprocess.servicebase.requestadditionaltime(v=vs.110).aspx This can be useful in avoiding the dreaded "marked for deletion" status. The maximum is set in the registry, so I usually request the max expected time the thread usually shuts down in (and never more than 12s). See: what is the maximum time windows service wait to process stop request and how to request for additional time

My code looks something like:

private Thread _worker;       
private readonly CancellationTokenSource _cts = new CancellationTokenSource(); 

protected override void OnStart(string[] args)
{
    _worker = new Thread(() => ProcessBatch(_cts.Token));
    _worker.Start();             
}

protected override void OnStop()
{            
    RequestAdditionalTime(4000);
    _cts.Cancel();            
    if(_worker != null && _worker.IsAlive)
        if(!_worker.Join(3000))
            _worker.Abort(); 
}

private void ProcessBatch(CancellationToken cancelToken)
{
   while (true)
   {
       try
       {
           if(cancelToken.IsCancellationRequested)
                return;               
           // Do work
           if(cancelToken.IsCancellationRequested)
                return;
           // Do more work
           if(cancelToken.IsCancellationRequested)
                return;
           // Do even more work
       }
       catch(Exception ex)
       {
           // Log it
       }
   }
}