microsoft.public.dotnet.framework.remoting

Ken Kolda

9/7/2004 3:38:00 PM

Your leak is coming from the fact that your ApplicationManager class derives
from RemotableObject, which has overriden the InitializeLifetimeServices()
method to return null. As a result, when your ApplicationManager class gets
remoted (which occurs when you subscribe to the Application's events since
the Application object lives in a different AppDomain), the remoting
framework will NEVER release this reference, thus the object is never
eligible for GC.

The easiest way to fix this in your code is to add a call to

RemotingServices.Disconnect(this);

in your StopApplication() method.

Also, instead of using Mutex's, you might just want to use the lock()
statement -- I didn't see any inherent reason why a Mutex was needed instead
of simply using lock(). I believe lock() is much more lightweight since it's
a .NET CLR thing instead of an operating system functionality, so that may
also help avoid the handle leak.

Ken


"Aaron" <Aaron@discussions.microsoft.com> wrote in message
news:1962AF62-542D-4951-BFA1-00A9DBC4D471@microsoft.com...
> Hi,
>
> I have developed a framework, using AppDomains, to allow other developmers
> to add plug-in's to our master application. I have written an application
> manager class that hides the implementation specifics of this. Recently I
> noticed the handle count of the application to climb as the application
> loaded and unloaded plug-in's. Extensive trial and error has lead me to
blame
> the events. If I subscribe to the event(s) of a plug-in, which resides in
> another appdomain, the Application manager class is never garbage
collected.
> Failing to subscribe measn that this class is cleaned up and all its held
> resources freed. The handle count rising is a consequence of this as when
> using events these mutex's are never destroyed.
>
> Rather than take my word for all this (I'm terrible at explaining this
> anyways), I have written a small console application to demonstrate what
is
> going on and this can be found at:
>
> http://home.netspeed.com.au/aaronthomas/Remoting...
>
> Code synopsis:
>
> - The entry point to the application is found in RemotingEvents.cs
> - There is a flag indicating the use of events in the main method called
> "UseEvents"
> - ApplicationManager.cs has the application manager implementation
>
> Free hi-5 to anyone that gets this one, and a big thanks to anyone that
> looks :)
>
> Aaron.
>
>
>