C# – Windows service stops automatically

cnetwindows-services

I made a Window service and let it work automatically and under localsystem account, when the service starts it fires this message for me and then stops

The [service name] service on local computer started and then stopped. Some Services stop automatically if they are not in use by another services or programs.

What's the problem and what's the solution?

Best Answer

Either you are not starting any threads on the OnStart method to do work, or there is an exception raised within your OnStart method.

If an exception is thrown, it will appear in the Windows Event log. The Windows Event log is a good place to start in any case.

Generally an OnStart method looks like this:

Thread _thread;

protected override void OnStart(string[] args)
{
    // Comment in to debug
    // Debugger.Break()

    // Do initial setup and initialization
    Setup();

    // Kick off a thread to do work
    _thread = new Thread(new MyClass().MyMethod)
    _thread.Start();

    // Exit this method to indicate the service has started
}

Related Solutions

C# – Windows Service to run constantly

The OnStart() callback needs to return in a timely fashion, so you'll want to kick off a thread where all your work will be performed. I would recommend adding the following fields to your class:

using System.Threading;
private ManualResetEvent _shutdownEvent = new ManualResetEvent(false);
private Thread _thread;

The _thread field will hold a reference to the System.Threading.Thread object you create in the OnStart() callback. The _shutdownEvent field holds a system-level event construct that will be used to signal the thread to stop running on service shutdown.

In the OnStart() callback, create and start your thread.

protected override void OnStart(string[] args)
{
     _thread = new Thread(WorkerThreadFunc);
     _thread.Name = "My Worker Thread";
     _thread.IsBackground = true;
     _thread.Start();
}

You need a function named WorkerThreadFunc in order for this to work. It has to match the System.Threading.ThreadStart delegate signature.

private void WorkerThreadFunc()
{
}

If you don't put anything in this function, the thread will start up and then immediately shutdown, so you have to put some logic in there that basically keeps the thread alive while you do your work. This is where the _shutdownEvent comes in handy.

private void WorkerThreadFunc()
{
    while (!_shutdownEvent.WaitOne(0)) {
        // Replace the Sleep() call with the work you need to do
        Thread.Sleep(1000);
    }
}

The while loop checks the ManualResetEvent to see if it is "set" or not. Since we initialized the object with false above, this check returns false. Inside the loop, we sleep for 1 second. You'll want to replace this with the work you need to do - monitor proxy settings, etc.

Finally, in the OnStop() callback of your Windows Service, you want to signal the thread to stop running. This is easy using the _shutdownEvent.

protected override void OnStop()
{
     _shutdownEvent.Set();
     if (!_thread.Join(3000)) { // give the thread 3 seconds to stop
         _thread.Abort();
     }
}

Hope this helps.

C# – Windows service on Local Computer started and then stopped error

If the service starts and stops like that, it means your code is throwing an unhandled exception. This is pretty difficult to debug, but there are a few options.

Consult the Windows Event Viewer. Normally you can get to this by going to the computer/server manager, then clicking Event Viewer -> Windows Logs -> Application. You can see what threw the exception here, which may help, but you don't get the stack trace.
Extract your program logic into a library class project. Now create two different versions of the program: a console app (for debugging), and the windows service. (This is a bit of initial effort, but saves a lot of angst in the long run.)
Add more try/catch blocks and logging to the app to get a better picture of what's going on.

Best Answer

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