dbus - comments requested, here's one

Luke Leighton lkcl at cb1.com
Fri Jun 25 05:53:12 PDT 2004


david, hi,

yes it helps, thank you.

CORBA as i explained is a cplusplusey style interface / programming
environment similar to DCOM *ON TOP OF* a c style interface / programming
environment and because it was Olivetti Labs that "dumped" a whole load of
code onto the open source community in 1996 (thank you to olivetti!) it is
kinda forgotten that there is a "straight" non-object-orientated interface
underneath corba's "object-orientated" one.

so, CORBA is totally of absolutely no value to KDE, however its underlying
non-object-orientated RPC mechanism might be.

so, the decision to disregard _all_ of CORBA i believe was made
prematurely.

it _might_ have been easy to split the OO from the non-OO, but you'll
never know, now :)


DCE/RPC let's see if the links are still valid...
yes it is:

http://www.opengroup.org/dce/

and you can see their RPCs, and the full DCE 1.2.2 documentation.

if you happen to be brave enough to download the DCE 1.2.2 source code
(a whopping 120mb if you include the docs) then yes, you will find coding
examples.

if you feel that that is too much, then there _are_ a couple of simple
working examples of code in freedce (the DCE 1.1 stuff).

btw DCE/RPC includes the means to do state-based programming (make one
function call and be returned a handle which can then be used in other
function calls to refer to "state" and then you have to call a close
routine to get rid of it) EVEN in cases where the underlying transport is
UDP based.

i'm a little tied up at the moment

also, if needs be, because the source code is available, it _is_ possible
to write "alternative" parsers for "alternative" IDL syntaxes.

so, there _is_ a "conversion" path to FreeDCE possible, thanks to the
foresight of the hundreds of people who contributed to DCE/RPC from DEC,
Apollo, IBM, HP, Fujitsu (i think) etc.

they designed the code to be really flexible.

by the way - this code (FreeDCE) is about the most comprehensive RPC
toolkit / runtime environment you'll _ever_ see.  Bayonne designed their
own RPC mechanism because they didn't know it existed.  the Andrew File
System (AFS) which used to be DCE/DFS 3.0 had to rip out DCE/RPC and
design their own RPC  mechanism when Transarc made AFS open source.

The GNU/Hurd had to design their own RPC mechanism because they hadn't
heard of DCE/RPC.

EVEN I hadn't heard of DCE 1.1 being "open source" when i started work on
samba tng back in 1997, and i HAND CRAFTED (*gibber*) TWENTY THOUSAND
LINES of DCE/RPC marshalling / unmarshalling code before i began to think
that maybe that wasn't such a good idea, started looking around and found
FreeDCE [i was gutted - but it only worked on redhat 5.1 at the time so i
had to wait another two years]

more later, i have to rush.

l.

On Fri, 25 Jun 2004, David Zeuthen wrote:

> On Mon, Jun 21, 2004 at 08:21:43PM +0100, Luke Leighton wrote:
> > _why_ are you reinventing the wheel?
> >
>
> There was a question like this some time ago that, here is a link
>
>  http://freedesktop.org/pipermail/dbus/2003-October/000509.html
>
> Hope this helps,
> David
>



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