Re: (now completed) Slides from my talk at CPA2000

[A E Lawrence <adrian.lawrence@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>]

jm40@xxxxxxxxx wrote:
> 
> > -----Original Message-----
> > From: Campbell, John [mailto:John.Campbell@xxxxxxxxxxxxxx]
> > Sent: 05 December 2000 17:44
> > To: 'Tom Locke'; occam-com@xxxxxxxxx; java-threads@xxxxxxxxx
> > Subject: RE: (now completed) Slides from my talk at CPA2000
> >
> >
> > Tom and Others
> >
> > > >The problem is that it's not much of an object if you have to sever
> > > >its existing channel connections before sending it.
> > >
> > > Could you elaborate on this?
> >
> > What I'm struggling to understand is how you avoid the problems
> > attendant to aliasing if you transport an object with open
> > connections.  It seems to me that even if you manage to avoid
> > aliasing of the *object* you're going to get it on the open
> > *channels*.
> 
> David May did some work on mobile processes which he presented at WoTUG-21.
> I asked someone at Bristol for a copy of the relevant papers (an occam-like
> langage called Icarus), but never heard anything more.  It was pretty
> interesting stuff though, worth looking at for this case.

It is on Henk Muller's pages, I think. Try also
http://www.cs.bris.ac.uk/Tools/Reports/Ps/2000-may.ps.gz ,
http://www.cs.bris.ac.uk/Tools/Reports/Ps/1998-may.ps.gz,
http://www.cs.bris.ac.uk/Tools/Reports/Ps/1998-muller-0.ps.gz
and there is 
"Using Channels for Multimedia Communication." with a note saying that
if you want a copy, you should email David (David.May@xxxxxxxxxxxxx).
Ditto
"A Simple Protocol to Communicate Channels over Channels." and
"Icarus language definition."


> > I'm supposing that when you move the channel object (as opposed
> > to a conventional OO object) out of its original context, the
> > original context cannot communicate with it.  That's what I meant
> > by "sever its connections". Is there a way to limit access to
> > a sent object such that you don't get aliasing, but it can
> > still interact with its original environment?

I think that you can get around any aliasing problems by using the same
methods that I used in dealing with mobile variables. I can't remember
how David and Henk managed that. Maybe Henk is listening and will remind
us? 

Adrian
-- 
Dr A E Lawrence