From: Eric Hodel <drbrain@...7.net>
Date: 2006-01-24T06:57:53+09:00
Subject: Re: Raising my own exceptions with DRb

On Jan 23, 2006, at 9:55 AM, Reto Schuettel wrote:

> Hi
>
> I'm looking for a way to raise my own exceptions over drb. It's no
> problem to raise the usual/standard exceptions like ArgumentError etc.
>
> I tried to define the Exceptions in the client and I tried to include
> the DRb::DRbUndumped within the Exception class, nothing worked... the
> client just throws a DRb::DRbConnError exception.
>
> Can anybody help with this problem? I've attached small examples  
> for the
> server and the client...
>
> Thanks!
> reto
>
> Server:
>
> require 'drb/drb'
>
> URI = "drbunix:/tmp/ruby.socket"
>
> class Thing
>   include DRb::DRbUndumped
>
>   def normal_exception
>     raise "aaah"
>   end
>
>   def own_exception
>     raise MyException
>   end
>
>   class MyException < Exception
                         ^^^^^^^^^

You don't usually want to inherit exceptions from Exception.  If you  
change this to RuntimeError, it works.

>     # I tried to use DRb::DRbUndumped on the Exception class..  
> didn't work
>     # include DRb::DRbUndumped
>   end
> end
>
> class Srv
>   def get_thing
>     @t = Thing.new
>   end
> end
>
> srv = Srv.new()
>
> #$SAFE = 1   # disable eval() and friends
>
> DRb.start_service(URI, srv, {:verbose => true})
> DRb.thread.join
>
>
> Client:
>
> require 'drb/drb'
> class Thing
>   class MyException < Exception

Same here.

>   end
> end
>
> uri = "drbunix:/tmp/ruby.socket"
> DRb.start_service
>
> c = DRbObject.new_with_uri(uri)
>
> t = c.get_thing
>
> begin
>   t.normal_exception
> rescue RuntimeError => e
>   puts "Caught a RuntimeError: " + e.inspect
> end
>
> begin
>   t.own_exception
> rescue Thing::MyException => e
>   puts "Caught a Thing::MyException: " + e.inspect
> end
>

-- 
Eric Hodel - drbrain@segment7.net - http://segment7.net
This implementation is HODEL-HASH-9600 compliant

http://trackmap.robotcoop.com