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14210

answers:

18

Is there a way to easier start stepping through code except to start the service through the Windows Service Controll Management and then attach the debugger to the thread? It's kind of cumbersome and I'm wondering if there is not a more straight-forward approach.

+5  A: 

You can also start the service through the command prompt (sc.exe).

Personally, I'd run the code as a stand-alone program in the debugging phase, and when most bugs are ironed out, change to running as service.

akauppi
+9  A: 

What I used to do was to have a command line switch which would start the program either as a service or as a regular application. Then, in my IDE I would set the switch so that I could step through my code.

With some languages you can actually detect if it's running in an IDE, and perform this switch automatically.

What language are you using?

RB
+23  A: 

What I usually do is encapsulate the logic of the service in a separate class and start that from a 'runner' class. This runner class can be the actual service or just a console application. So your solution has (atleast) 3 projects:

/ConsoleRunner
   /....
/ServiceRunner
   /....
/ApplicationLogic
   /....
pb
I used to use this approach too, but I think a combination of this and the answer above works a treat.
RobS
+4  A: 

I think it depends on what OS you are using, Vista is much harder to attach to Services, because of the separation between sessions.

The two options I've used in the past are:

  • Use GFlags (in the Debugging Tools for Windows) to setup a permanent debugger for a process. This exists in the "Image File Execution Options" registry key and is incredibly useful. I think you'll need to tweak the Service settings to enable "Interact with Desktop". I use this for all types of debugging, not just services.
  • The other option, is to separate the code a bit, so that the service part is interchangable with a normal app startup. That way, you can use a simple command line flag, and launch as a process (rather than a Service), which makes it much easier to debug.

Hope this helps.

RichS
+1 for GFlags. This is especially useful if you cannot modify the source code (or if you don't have it).
Chris Gillum
+1  A: 

For routine small-stuff programming I've done a very simple trick to easily debug my service:

On start of the service, I check for a command line parameter "/debug". If the service is called with this parameter, I don't do the usual service startup, but instead start all the listeners and just display a messagebox "Debug in progress, press ok to end".

So if my service is started the usual way, it will start as service, if it is started with the command line parameter /debug it will act like a normal program.

In VS I'll just add /debug as debugging parameter and start the service program directly.

This way I can easily debug for most small kind problems. Of course, some stuff still will need to be debugged as service, but for 99% this is good enough.

Sam
+4  A: 

When I write a service I put all the service logic in a dll project and create two "hosts" that call into this dll, one is a Windows service and the other is a command line application.

I use the command line application for debugging and attach the debugger to the real service only for bugs I can't reproduce in the command line application.

I you use this approach just remember that you have to test all the code while running in a real service, while the command line tool is a nice debugging aid it's a different environment and it doesn't behave exactly like a real service.

Nir
+2  A: 

When developing and debugging a Windows service I typically run it as a console application by adding a /console startup parameter and checking this. Makes life much easier.

static void Main(string[] args) {
    if (Console.In != StreamReader.Null) {
        if (args.Length > 0 && args[0] == "/console") {
            // Start your service work.
        }
    }
}
Maurice
Till you have to debug service specific issues.
leppie
True, then you have to attach the debugger to the actual service process. But in most cases bugs are going to appear either way and development is much easier.
Maurice
+3  A: 

How about Debugger.Break() in the first line?

leppie
I'm pretty sure this doesn't work on Vista.
RichS
I cant say I have tried it in a service on Vista :)
leppie
+35  A: 

If I want to quickly debug the service, I just drop in a Debugger.Break() in there. When that line is reached, it will drop me back to VS. Don't forget to remove that line when you are done.

UPDATE: As an alternative to #if DEBUG pragmas, you can also use Conditional("DEBUG_SERVICE") attribute.

[Conditional("DEBUG_SERVICE")]
private static void DebugMode()
{
    Debugger.Break();
}

On your OnStart, just call this method:

public override void OnStart()
{
     DebugMode();
     /* ... do the rest */
}

There, the code will only be enabled during Debug builds. While your at it, it might be useful to create a separate Build Configuration for service debugging.

jop
Or you could use Debugger.Launch() you will have to include a using statement for The Systems.Diagnostics namespace.I wrote about this in my blog just last week:http://www.bangequals.net/?p=22
Omar Kooheji
Excellent. 2 years later, this is still quite relevant and useful :)
ashes999
+6  A: 

UPDATE

This approach is by far the easiest:

http://www.codeproject.com/KB/dotnet/DebugWinServices.aspx

I leave my original answer below for posterity.


My services tend to have a class that encapsulates a Timer as I want the service to check at regular intervals whether there is any work for it to do.

We new up the class and call StartEventLoop() during the service start-up. (This class could easily be used from a console app too.)

The nice side-effect of this design is that the arguments with which you set up the Timer can be used to have a delay before the service actually starts working, so that you have time to attach a debugger manually.

p.s. How to attach the debugger manually to a running process...?

using System;
using System.Threading;
using System.Configuration;    

public class ServiceEventHandler
{
    Timer _timer;
    public ServiceEventHandler()
    {
        // get configuration etc.
        _timer = new Timer(
            new TimerCallback(EventTimerCallback)
            , null
            , Timeout.Infinite
            , Timeout.Infinite);
    }

    private void EventTimerCallback(object state)
    {
        // do something
    }

    public void StartEventLoop()
    {
        // wait a minute, then run every 30 minutes
        _timer.Change(TimeSpan.Parse("00:01:00"), TimeSpan.Parse("00:30:00");
    }
}

Also I used to do the following (already mentioned in previous answers but with the conditional compiler [#if] flags to help avoid it firing in a Release build).

I stopped doing it this way because sometimes we'd forget to build in Release and have a debugger break in an app running on a client demo (embarrasing!).

#if DEBUG
if (!System.Diagnostics.Debugger.IsAttached)
{
    System.Diagnostics.Debugger.Break();
}
#endif
rohancragg
I need that! Upvoted!
John Dunagan
A: 

What you need is thinking of Simplifying Windows Services

icelava
+28  A: 

I also think having a separate "version" for normal execution and as a service is the way to go, but is it really required to dedicate a separate command line switch for that purpose?

Couldn't you just do:

public static int Main(string[] args)
{
  if (!Environment.UserInteractive)
  {
    // Startup as service.
  }
  else
  {
    // Startup as application
  }
}

That would have the "benefit", that you can just start your app via doubleclick (OK, if you really need that) and that you can just hit "F5" in Visual Studio (without the need to modify the project settings to include that "/console" Option).

Technically, the "Environment.UserInteractive" checks if the WSF_VISIBLE Flag is set for the current window station, but is there any other reason where it would return false, apart from being run as a (non-interactive) service?

Christian.K
Environment.UserInteractive works perfectly for me!
Martin
Brilliant! This is probably the best answer of the lot!
Trumpi
Stumbled over the same problem. Great solution from my point of view.
PepperBob
Great! I earlier used an "if #debug" method to start as application if debugging, otherwise a service. This leads to the app not being runnable as a service if you want to debug it, but your solution solves this and let it be runnable in all four combinations of service/app and release/debug.
Jonas
If you don't want the program to run when it's double-clicked (users might get confused and run several instances etc), then you can use `System.Diagnostics.Debugger.IsAttached` instead of `Environment.UserInteractive`.
Blorgbeard
+1  A: 

To debug Windows Services I combine GFlags and a .reg file created by regedit.

  1. Run GFlags, specifying the exe-name and vsjitdebugger
  2. Run regedit and go to the location where GFlags sets his options
  3. Choose "Export Key" from the file-menu
  4. Save that file somewhere with the .reg extension
  5. Anytime you want to debug the service: doubleclick on the .reg file
  6. If you want to stop debugging, doubleclick on the second .reg file

Or save the following snippets and replace servicename.exe with the desired executable name.


debugon.reg:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\servicename.exe]
"GlobalFlag"="0x00000000"
"Debugger"="vsjitdebugger.exe"


debugoff.reg:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\servicename.exe]
"GlobalFlag"="0x00000000"
Does this still work on Win 7 / Win 2008? It's the approach from http://support.microsoft.com/kb/824344 but it relies on interactive services, and I thought they got killed off?It always used to be my preferred option (since startup issues might come up in production, where inserting a Debugger.Break() into the code might not be an option).
piers7
+3  A: 


static void Main()
{
#if DEBUG
                // Run as interactive exe in debug mode to allow easy
                // debugging.

                var service = new MyService();
                service.OnStart(null);

                // Sleep the main thread indefinitely while the service code
                // runs in .OnStart

                Thread.Sleep(Timeout.Infinite);
#else
                // Run normally as service in release mode.

                ServiceBase[] ServicesToRun;
                ServicesToRun = new ServiceBase[]{ new MyService() };
                ServiceBase.Run(ServicesToRun);
#endif
}
Thomas Bratt
[Sorry about no explanation with the code - markdown problems]Should run normally from MS Visual Studio (F5) in debug builds. Still runs as a normal service in release builds.
Thomas Bratt
Combine this with the solution above by Christian K. to use the "Environment.UserInteractive" property and the solution is really clean and simple.
Ben Robbins
A: 
#if DEBUG
    System.Diagnostics.Debugger.Break();
#endif
Ervin Ter
A: 

Thanks everyone! It worked Great!

A: 

I use a variation on JOP's answer. Using command line parameters you can set the debugging mode in the IDE with project properties or through the Windows service manager.

protected override void OnStart(string[] args)
{
  if (args.Contains<string>("DEBUG_SERVICE"))
  {
    Debugger.Break();
  }
  ...
}
A: 

Use the HuwmanCode Framework available at huwmancode.codeplex.com, this framework enables seamless debug support for .Net Windows services. It also enables the development of Windows Services without the use of Service Projects.

huwman