Re: Distributed Ada, robustness etc.

["Dr. Adrian Wrigley" <amtw@linuxchip.demon.co.uk.uk.uk>]

On Wed, 31 May 2006 15:21:45 +0200, Jean-Pierre Rosen wrote:

> Dr. Adrian Wrigley a �crit :
>> Unfortunately, the unregister call *always* fails.  I had
>> implemented the call through the finalization of a Controlled
>> type.  An instance of the type is in the package, and the
>> Finalize procedure is called when the partition terminates.
>> This call, however, seems to take place *after* the PCS for
>> the partition is brought down, and so the unregister
>> immediately fails.
>> 
> Note that finalization occurs in reverse order of elaboration. 
> Therefore, this means that your package is elaborated *before* the PCS.

OK.  I don't think I understand the problem I'm having.

The package makes a "register" RCI call when it is being
elaborated.  This works fine (it's what I expected).
Doesn't that mean that I should be able to "unregister" it
when finalizing?

The error I got was:

raised SYSTEM.GARLIC.COMMUNICATION_ERROR : Send: Cannot connect to 1
autotrade_client

on the terminal where autotrade_client was invoked.

The autotrade_client partition contains the server package being
terminated, but is a different partition from the RCI nameserver.
The nameserver never gets the unregister.

> Maybe adding a (useless) "with system.rpc" to your package would suffice 
> to have an appropriate elaboration, and therefore finalization, order

I'll try this when I can.  I'll also try to see whether the PCS
is really being finalized prematirely.

Thanks for the hint!
--
Adrian