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=-1.9 required=5.0 tests=BAYES_00
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 border1.nntp.dca1.giganews.com!nntp.giganews.com!usenet.blueworldhosting.com!feeder01.blueworldhosting.com!feeder.erje.net!eu.feeder.erje.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
From: Niklas Holsti <niklas.holsti@tidorum.invalid>
Newsgroups: comp.lang.ada
Subject: Re: Simp,e example for 2 tasks
Date: Mon, 22 Sep 2014 21:16:14 +0300
Organization: Tidorum Ltd
Message-ID: <c8b7b9Fk1l2U1@mid.individual.net>
References: <9b22dd09-6137-4f4b-8be1-28255032df70@googlegroups.com>
 <VuDTv.262712$_k.68089@fx16.iad> <lvncmq$iim$1@dont-email.me>
 <c8a0qcF9regU1@mid.individual.net> <lvpnd2$7q8$2@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
X-Trace: individual.net ZFM2RAjflKTyf6997jURoggkvm/vmvwD3PlY9YiKGMg8L976TU
Cancel-Lock: sha1:NF2tr3KIeFpHX6V81TM1gjQgWsM=
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8;
 rv:24.0) Gecko/20100101 Thunderbird/24.6.0
In-Reply-To: <lvpnd2$7q8$2@dont-email.me>
Xref: number.nntp.dca.giganews.com comp.lang.ada:189089
Date: 2014-09-22T21:16:14+03:00
List-Id: <comp.lang.ada>

On 14-09-22 20:48 , Jeffrey Carter wrote:
> On 09/22/2014 12:18 AM, Niklas Holsti wrote:
>>
>> Hmm... I don't quite agree with that. It seems to me that rendez-vous
>> interaction between tasks could be implemented in a distributed system,
>> as long as the entry parameters can be passed by value or by copy-in
>> copy-out. It is the global shared variables and reference parameters
>> that would make a distributed approach difficult for Ada programs using
>> such constructs. I don't know Erlang well enough to understand if it has
>> some solution for that, or if it simply forbids such things.
> 
> Well, of course one can implement rendezvous between tasks in different
> partitions in a distributed system, since that's possible through the DSA.

I meant, rather, that an Ada RTS could have implemented distributed
rendez-vous without (and before) the DSA -- that the mere fact that
rendez-vous is synchronous does not mean that it cannot be distributed.
Of course the performance, in terms of latency, would be of a different
order than rendez-vous within tasks on the same core.

I'd bet that most distributed systems today communicate through
synchronously used, bidirectional, TCP request-reply streams, not
through asynchronous message-passing with long queues. But I include
web-based applications as distributed systems.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
      .      @       .