Re: [boost] Active objects?

From: Scott Woods (scottw_at_[hidden])
Date: 2005-11-02 14:09:26

----- Original Message -----
From: "Andy Little" <andy_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Wednesday, November 02, 2005 10:14 PM
Subject: Re: [boost] Active objects?

> "Scott Woods"  wrote
>
> >  Symmetric  interaction  between groups of peer objects
> > is a  different model of operation. Any object  can "call"
> > any other object and there is no "return" (i.e. future). Most
> > of my async-programming problems seem to fall into the
> > latter category.
>
> I'm certainly no expert in threads, but I'm fascinated by the idea of
'symmetric
> interaction'. Do you have a short example of symmetric interaction
***Only***
> ?( without any other structure to the system). I ask because it sounds
like a
> recipe for chaos.

Ha. Reading my message after your feedback, it does.

Surely in any practical system, there must be a
> higher level of organisation than this?
>

I used the word symmetric to try and distinguish the nature of objects in
the world of D. Schmidt, from those of H. Sutter. It refers to the
equivalent
potentials that each object has to send messages (to HS; call a queuable
method) to another object. There is an asymmetry on the HS model where
calls are made to an active object and information is returned through the
future
concept. In a world such as that of DS (also refer to SDL) all exchange
of information is through the same mechanism.

Of course, they do not send the same messages (was this your concern? :-).

The "higher level of organisation" that you expect would manifest
itself in the different messages being sent, e.g. CHALLENGE, WELCOME
and the different roles that each object has in an exchange.