From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
Path: 
 border2.nntp.dca1.giganews.com!nntp.giganews.com!usenet.blueworldhosting.com!feeder01.blueworldhosting.com!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail
From: Pascal Obry <pascal@obry.net>
Newsgroups: comp.lang.ada
Subject: Re: confusion about message passing between the tasks
Date: Sun, 26 Oct 2014 09:14:05 +0100
Organization: Home - http://www.obry.net
Message-ID: <1414311245.15950.84.camel@obry.net>
References: <d377c4f7-8c89-4b60-907d-f9151ae02721@googlegroups.com>
 <s9mn4alvqkbtu6kfhqphc3im4akn69641v@4ax.com> <m2go3u$ors$2@dont-email.me>
 <wcc8uk3kcuy.fsf@shell01.TheWorld.com> <m2i1aq$eq1$1@dont-email.me>
Reply-To: pascal@obry.net
NNTP-Posting-Host: L4qXF0oMjLhAq3aIIazdYA.user.speranza.aioe.org
Mime-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Complaints-To: abuse@aioe.org
X-Mailer: Evolution 3.12.7-1 
X-Notice: Filtered by postfilter v. 0.8.2
Xref: number.nntp.giganews.com comp.lang.ada:190051
Date: 2014-10-26T09:14:05+01:00
List-Id: <comp.lang.ada>

Le dimanche 26 octobre 2014 =C3=A0 06:37 +0100, J-P. Rosen a =C3=A9crit :=
=20
> I view protected objects as a much lower level abstraction than
> rendezvous; they are nice for simple synchronisation and simple needs,
> but they don't scale up well for higher level abstactions. Try to
> Ravenscarize (!) existing software that uses rendezvous, and you'll see
> what I mean (I did that recently).
>=20
> And don't forget that with PO, you lose a very nice and poweful feature
> of rendezvous: automatic termination.

Agreed, but with PO you avoid synchronization and that is one feature
that can give you full speed in large simulations with many tasks. A
rendez-vous is ok when the tasks are not waiting too much for each
others, and this is never possible.

A PO is then a good use as a buffer for data being exchanged without
requiring a task to wait for another.

To me both rendez-vous and PO are really nice features of the language
and I don't see one of them removing the need for the other.

--=20
  Pascal Obry /  Magny Les Hameaux (78)

  The best way to travel is by means of imagination

  http://v2p.fr.eu.org
  http://www.obry.net

  gpg --keyserver keys.gnupg.net --recv-key F949BD3B