Hello!
I have a remoting server which exposes a Singleton object to a client.
The client can call methods on the object without any problem.

Now, I'm trying to let the client modify the exposed object.
My question is: How would the server be able to load the exposed object
an retrieve the value set by the client? I'm asking because there is no
mention of the currently exposed instance of the class in the server code.

Or how do I expose a named instance of an abject to my clients? (having
a named instance would probably solve my problem)

Thanks

Allow the server to access the same object which is remoted to the clients
is a frequently occurring problem in remoting. Luckily, the answer is pretty
simple. Currently, you've probably registered your remoting object using
RemotingConfiguration.RegisterWellKnownServerObjec t(). The problem is that
this method exposes the object anonymously, i.e. the server doesn't have a
reference to this instance.

To fix this, you do two things:

1) Declare and instantiate a named instance of your remote object.
2) Get rid of your call to RegisterWellKnownServerObject() and instead call
RemotingServices.Marshal() on your named object. This will expose the object
so it can accept client requests.

Hope that helps -
Ken


"news.microsoft.com" <xxx (AT) xxx (DOT) com> wrote

You're seeing 2 and 4 because you've registered the Clock type as SingleCall
instead of Singleton. When a type is SingleCall, ever property/method you
access causes a new instance of the object to be created to service the
request. So, in your client code where you have:

Console.WriteLine ("Clock " +
clock.Number.ToString() + " " +
clock.GetCurrentTime ());

the "clock" instance used to access the "Number" property is actually
different from the instance used to call the GetCurrentTime() method, even
though from the client's side these appear to be the same instance.

What you are likely trying to achieve is that you get a new instance in each
iteration of the loop. In that case, you need to use client-activated
object. To do this, use RegisterActivatedServerType() on the server side and
RegisterActivatedClientType() on the client side. Then your code will behave
as you expect.

Ken


"Rob Richardson" <notreally (AT) n2net (DOT) net> wrote

Ken,

Thanks for your reply. I am a newbie in this area, and do not know about
named objects. I haven't found a clear sample on the Web. Could you point
me to a sample of this technique?

Thanks again!

Rob

Thanks again, Ken. Now that somebody who knows what he's doing explains it,
it makes sense!

Rob

Ken,

I tried using RemotingServices.Marshal() as you suggested. It worked!

In the server, I replaced:
RemotingConfiguration.RegisterWellKnownServiceType (typeof (Clock), "Clock",
WellKnownObjectMode.SingleCall);
with:
Clock serverClock = new Clock();
serverClock.Number = 99;
ObjRef serverClockRef = RemotingServices.Marshal(serverClock,
"ServerClockURI");

In the client, I replaced:
RemotingConfiguration.RegisterWellKnownClientType (typeof (Clock),
"tcp://localhost:1234/Clock");
with:
RemotingConfiguration.RegisterWellKnownClientType (typeof (Clock),
"tcp://192.168.1.29:1234/ServerClockURI");

The client application happily reported that it was using clock number 99.

Next question: For my application as it is currently designed, this will
suffice, since there will never be more than a single client communicating
with a server. But what happens when we decide that a single server
application will manage an unknown number of printers? In that case, I
would want my objects to be client-activated, but I still want the server to
know what objects it created. How do I do that?

Thanks again!

Rob

In this case, you probably want to go with a factory model. In this model,
you create a singleton SAO which serves up your CAOs. By doing this you're
able to keep a hold of references to the same CAOs used by the clients. For
a good explanation of implementing a factory model in remoting, check out:

http://www.glacialcomponents.com/ArticleDetail/CAOGuide.aspx

Ken


"Rob Richardson" <notreally (AT) n2net (DOT) net> wrote