Re: Event Server, Callbacks, ...

[Marcelo CB <corbani async com br>]

Thanks a lot. 

There is a bit I still don't get ... shouldn't I have
'someone listening' to the event push from the server ? 

What I mean is that at server side I leave control to the
CORBA_ORB_run() which takes care of listening and handling client
requests. But at client side, who will be listening  to it, since I
control the main ( and only ) thread of execution ? What if I want to use
GTK and leave control to gtk_main() ?


On Thu, 19 Oct 2000, Darrin Thompson wrote:

> Here are some possible solutions:
> 
> If you used an event server (TAO has a standalone one that should work 
> fine with ORBit) you could do this:
> 
> Server object is a push supplier to the event service.
> 
> Client objects are push consumers of the event service.
> 
> When a change happens:
> 
> Server object pushes an event with information about a change.
> 
> Client objects all receive the event. 
> 
> Client objects all take action as soon as they receive the event.
> 
> ******
> You can get around the lack of event service by doing this:
> 
> Server object has a "register" method. 
> 
> Clients also implement a "receive notification" object.
> 
> At client startup:
> 
> Client creates the receive notification object. Client calls the servers 
> "register" method with a reference to the notification object.
> 
> When a change happens:
> 
> The server calls a method on all the receive notification objects it 
> knows about. This is kind of a pain because some of the objects may have 
> died mysteriously with their clients.
> 
> Hope this drivel helps.
> 
> Darrin
> 
> >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<
> 
> On 10/19/00, 9:08:52 AM, Marcelo CB <corbani async com br> wrote regarding 
> Event Server, Callbacks, ...:
> 
> 
> > In an application I'm implementing I have a server object holding a
> > frequently changed list, and I need the clients to be warned when changes
> > happen to the list.
> 
> > It seems to me at first that I need something like an event-server, (
> > unavailable in ORBit ) but it is still unclear to me how would my client
> > 'be warned' of the changes.
> 
> > I thought the solution would be to have something like a server
> > thread in each client ( ORBit-mt ? ) and a client within the server ( the
> > list server itself ) to make the messaging delivery.
> 
> > As you see, the thing is kind of messy in my head, and though I read the
> > Event Server chapter in the 'Advanced CORBA Programming ', the OMG spec
> > for the event services, and read some things Wilhelmi wrote, I seem not 
> to
> > get it.
> 
> > Maybe I'm just too dumb and need some help.
> 
> > --
> > Marcelo Corbani de Barros                   corbani async com br
> > Async Open Source Development - Brasil
> 
> 
> > _______________________________________________
> > orbit-list mailing list
> > orbit-list gnome org
> > http://mail.gnome.org/mailman/listinfo/orbit-list
> 
> _______________________________________________
> orbit-list mailing list
> orbit-list gnome org
> http://mail.gnome.org/mailman/listinfo/orbit-list
> 

Marcelo Corbani de Barros                   corbani async com br
Async Open Source Development - Brasil