Lots of concurrency
Gary McGovern
garywork at lineone.net
Wed Oct 31 02:41:11 UTC 2001
Before the thread and subject dies an interesting lecture by His Holiness
the Dalai Lama did mention that a sentient being may be incarnate in more
than one body at once in separate spaces. Unfortunately the Tibetan
Government in Exile have since deleted that lecture from their site so I
cannot look up further information.
I mention that only on a conceptual basis relevant to parallelism and points
of view and make no personal claims.:-)
Regards,
Gary
----- Original Message -----
From: "Alan Kay" <Alan.Kay at squeakland.org>
To: <squeak-dev at lists.squeakfoundation.org>
Sent: Tuesday, October 30, 2001 11:47 PM
Subject: RE: Lots of concurrency
> Mtichel Resnick wrote an excellent little paper a few years ago
> http://www.media.mit.edu/~mres/papers/JLS/JLS-1.0.html "Beyond the
> Centralized Mindset" (his bibliography is at
> http://www.media.mit.edu/~mres/papers.html , and many of his papers
> are online).
>
> One of his very interesting opinions about the problems he observed
> was that they didn't seem to be so much about "concurrency being
> hard", but that it was quite difficult for students of most ages
> (even high school students) to be able to take the point of view of
> one of the little particles and to think about what it could see and
> do. This "taking a different point of view other than your own" was a
> centerpiece of some of Piaget's work. In theory, this is supposed to
> get easier as you get older, but it also seems to be something that
> has to be learned, and many don't learn it. The students had a kind
> of god-like, from their POV, way of looking at the world -- much like
> programmers who start off with simple algorithms munging
> datastructures. This doesn't scale well. In good OOP, the programmer
> should take the POV of the object in its environment, and help the
> object become self-sufficient, productive and robust. This way of
> programming really opens the doors to concurrency.
>
> Cheers,
>
> Alan
>
> ------
>
>
> At 11:17 PM +0100 10/30/01, G.J.Tielemans at dinkel.utwente.nl wrote:
> >Children and students live in this era:
> >- They can send each other emails, it is possible to send eamils to a
list
> >- They can send each other SMS, it is possible to send an sms to a group
> >- They can chat in a chatbox, private or in a group
> >
> >
> >> -----Original Message-----
> >> From: Ken Kahn [mailto:kenkahn at toontalk.com]
> >> Sent: dinsdag 30 oktober 2001 20:33
> >> To: squeak-dev at lists.squeakfoundation.org
> >> Subject: Re: Lots of concurrency
> >>
> >>
> >> Richard A. O'Keefe wrote:
> >>
> >> >
> >> > The question I think is interesting is whether telling students to
> >> > think in terms of objects TALKING to each other makes it harder for
> >> > them to think of concurrent implementations. Would some other
> >> > metaphor (perhaps sending couriers with messages, or thinking about
> >> > a factory with things concurrently moving from machine to machine
> >> > at the same time) make it easier for them to think of and understand
> >> > concurrency?
> >> >
> >>
> >> Before settling upon a carrier pidgeon metaphor for
> >> communcation in ToonTalk
> >> I considered lots of other alternatives including a postal
> >> system with mail
> >> carriers and mail boxes, rivers where you can place floating
> >> messages to
> >> those downstream, wires, fax machines, email, and telephones. I never
> >> considered face-to-face talking since I took for granted that
> >> objects are
> >> spread out spatially. I think the answer to Richard's
> >> question is that the
> >> right choice of metaphor can significantly facilitate thinking and
> >> understanding concurrent programs.
> >>
> >> Wires may be how messages are really passed within and
> >> between computers but
> >> wires are not an ideal metaphor. The messages are invisible.
> >> Wires cannot be
> >> sent along wires. Directionality isn't apparent. Wireless
> >> communication is
> >> even worse.
> >>
> >> Talking or telephones aren't good because both parties need
> >> to be available
> >> at the same time. Many-to-1 communication by telephone is
> >> confusing. While
> >> phone numbers can be communicated over the phone that would
> >> lead to a model
> >> where numbers denote objects or communication channels. So
> >> can they be made
> >> up and dialed at random? Not good.
> >>
> >> Even the postal system doesn't provide an ideal metaphor. If
> >> you want to
> >> send the receiving end of a communication channel to someone
> >> do you have to
> >> pick up your mail box and send it by mail to someone? And
> >> then does the
> >> postal system know that the mailbox has moved or do you need
> >> to think about
> >> forwarding addresses?
> >>
> >> A bird that when given something flies to her nest and leaves
> >> it there and
> >> returns works out very well. You can give a bird a box that
> >> might contain
> >> other birds and nests - not too strange. The only strange
> > > thing is that a
> >> bird always finds her nest no matter where it has been moved
> >> to. But that
> >> doesn't seem to cause any confusion.
> >>
> >> > All I know about Ken Kahn's ToonTalk is what I've read in
> >> this thread,
> >> > but it sounds as though uses a "physical" rather than "verbal"
> >> > metaphor, so I think his observations are particularly
> >> interesting here.
> >> >
> >>
> >> You all are welcome to try out ToonTalk. There is a free
> >> trial version and
> >> you are all welcome to try to beta version as well. It only
> >> runs on PC with
> >> Windows (or Macs emulating a PC with Windows - don't know about Linux
> >> emulators). Details at www.toontalk.com
> >>
> >> Best,
> >>
> >> -ken kahn
> >>
> >>
> >>
> >>
>
>
> --
>
>
>
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