以编程方式授予/拒绝Windows服务的onStop功能

Question

I know that I can deny onStop feauture by setting CanStop option to false in Service's properties. This is not what I want cause this will permanently deny onStop capabilities.

What I want is to grant/deny stop capabilities programmatically. My service lifecycle is pretty simple:

starts => { run some action => sleeps for 2 minutes } x nTimes => stop

What I would is to deny stop capabilities when service is in action and grant that feature when service is idle (ie If user try to stop it when not permitted nothing happen, else the service really stop itself).

This is how my service is written, I have various way to understand if is idle.

partial class Service : ServiceBase
    {
        private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
        private DateTime _lastRun = DateTime.Now;
        private System.Timers.Timer _timer = new System.Timers.Timer(Convert.ToInt32(ConfigurationManager.AppSettings["pollingInterval"]) * 60 * 1000);

        public Service()
        {
            InitializeComponent();
        }

        private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            _timer.Enabled = false;
            DateTime now = DateTime.Now;
            if (now.Minute > _lastRun.Minute)
            {
                ClientVS cvs = new ClientVS();
                cvs.run();
            }
            _lastRun = now;
            _timer.Enabled = true;
        }

        protected override void OnStart(string[] args)
        {
            log.Info("Started");
            _timer.Elapsed += timer_Elapsed;
            _timer.Start();
        }

        protected override void OnStop()
        {
            log.Info("Stopped");
        }
    }

Answer 1

Don't do this. Service must stop promptly (5 seconds or less) when requested to stop. If you delay or deny stop requests from SCM, you are guaranteed to annoy your users when they reboot computer. You can potentially change service configuration dynamically, but it is probably bad idea, because changing serice config frequently does not sound right.

Semantics of the service STOP command is just this -- service has to stop at the earliest safe place. Your action is different than that. What I would recommend is to implement a custom mechanism that would represent your semantics exactly (that is, do NOT reuse STOP command). There are couple of way to do this:

1. Any sort of IPC mechanism. A named event would probably be easiest to implement. A service will create a named event and wait for it in one of the background threads. When event is set (by your user mode application), it would do necessary checks and would call ServiceBase.Stop conditionally.

2. Invent a custom service control command. This is easy to do, just override ServiceBase.OnCustomCommand , make up an integer between 128 and 255, that would represent your command, and implement OnCustomCommand to call ServiceBase.Stop conditionally. To send custom command to service you can use API or sc control command. Assuming you made up 234 as you new command:

sc control MyService 234