Question

So I’ve got a Windows service written in c#. The service class derives from ServiceBase, and starting and stopping the service calls instance methods OnStart and OnStop respectively. Here’s SSCE of the class:

partial class CometService : ServiceBase
{
    private Server<Bla> server;
    private ManualResetEvent mre;
    public CometService()
    {
        InitializeComponent();
    }       
    protected override void OnStart(string[] args)
    {
        //starting the server takes a while, but we need to complete quickly
        //here so let's spin off a thread so we can return pronto.
        new Thread(() =>
        {
            try
            {
                server = new Server<Bla>();
            }
            finally
            {
                mre.Set()
            }
        })
        {
            IsBackground = false
        }.Start();
    }

    protected override void OnStop()
    {
        //ensure start logic is completed before continuing
        mre.WaitOne();
        server.Stop();
    }
}

As can be seen, there’s quite a lot of logic that requires that when we call OnStop, we’re dealing with the same instance of ServiceBase as when we called OnStart.

Can I be sure that this is the case?

Answer 1

If you look in the Program.cs class, you’ll see code like the following:

private static void Main()
{
    ServiceBase.Run(new ServiceBase[]
                {
                    new CometService()
                });
}

That is, the instance is created by code within your own project. It’s that one instance that all Service Manager calls (including OnStart and OnStop) are made against.