Re: ref counting in Bonobo

[sopwith redhat com (Elliot Lee)]

On 29 Sep 1999 09:22:48 -0400, Svanberg Liss <lisss@ydab.se> wrote:
>> I was wondering about the implications of the ref counting routines in the
>> Unknown interface.  If I have a remote client that's holding a reference
>> to an object in a server, and the client crashes, what happens?
>>
>> I've heard that Microsoft is trying to implement distributed garbage
>> collection in COM+ 2.0.  And I mean full mark-and-sweep type garbage
>> collection.  It's hard to imagine making that work.
>>
>> Do Bonobo client programs explicitly call ref and unref on server objects,
>> or is this all handled transparently by Gnome?
>
>There is nothing wrong with refcounting, as long as you can exiplictly kill
>an object.
>
>This is a problem with COM. If a client crashes, you cannot relese the
>object, because only the one that refcounted the object may release it.
>( This is at least what I've been told :)
>
>I don't see why this should be a problem in bonobo.
>( Of course I can see why, I mean that it's possible to solve the problem
>without so much effort! :)
>The refcounts are not bound to a specific client in bonobo, so it should be
>possible to write something that pings various clients to see if they are
>alive, and if not releases the object they have been bound to.
>Or one that allows the sysadmin to release objects.
>
>In the case of containers/containees this would not even require any strange
>extra applications, because both container and containee has got callbacks
>that the remote application should call when something happens.
>If the "client" on the other side has died, CORBA will throw a system
>exeption. The "server" catches the exeption, realizes that something is
>funny about the "client", it then releases itself ( and thereby decoupling
>itself from the "client" ).
>
>The only real problem appears to be the interfaces ( GNOME::Storage /
>GNOME::Stream ) that has no callbacks. On the other side, none of those
>objects are supposed to stay alieve for a prolonged time, are they?
>
>// Liss
>
>
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-- 
-- Elliot					http://developer.gnome.org/
The first thing a programmer needs to admit is that any program is by far
more complex than his own mind. Thats why he partitions it into neat
pieces and avoids complexity.