From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: PAR (Was: Embedded languages based on early Ada)
Date: Fri, 9 Mar 2007 19:50:26 -0600
Date: 2007-03-09T19:50:26-06:00 [thread overview]
Message-ID: <est2pq$9u$1@jacob-sparre.dk> (raw)
In-Reply-To: uvehbtxpn.fsf@STRIPCAPStelus.net
"Ray Blaak" <rAYblaaK@STRIPCAPStelus.net> wrote in message
news:uvehbtxpn.fsf@STRIPCAPStelus.net...
> "Randy Brukardt" <randy@rrsoftware.com> writes:
> > A parallel subprogram would be defined by the keyword parallel. They
would
> > be like a normal Ada subprogram, except:
> > * Access to global variables is prohibited, other than protected
> > objects, atomic objects, and objects of a declared parallel type. Note
that
> > this also includes global storage pools!
>
> I understand the reason for this restriction, but fear that it is not
useful
> in practice. This would prevent the use of regular library calls, unless
those
> libraries are pure. Is that reasonable?
I think so (see below).
> Hmm, maybe those libraries can be access via calls from protected objects
> only?
Right. And I'd expect "parallel" versions of many things to be constructed.
(Surely containers.) Intrinsics like "+" and "**" would be defined to be
"parallel". Everything in a pure package could be considered "parallel" as
well (and if a pure function was given a first class definition, they could
be too -- but only if they are checked).
I neglected the obvious restriction that a parallel routine isn't allowed to
call a non-parallel routine (just like a pure package can't depend on an
impure package). Else the restrictions could be trivially circumvented.
> I am wondering if this restriction makes things too onerous for the
programmer
> to use the library environment they have access to, especially as compared
to
> normal sequential programming.
Well, that's the big question, isn't it? But I don't think it is necessarily
impossible; in this sense it is much like SPARC, which adds a lot of
restrictions to Ada in order to get the ability to formally prove the
programs (and in a reasonable amount of time). People are willing to use
that, why not parallel restrictions? It just depends on the possible gain.
Randy.
next prev parent reply other threads:[~2007-03-10 1:50 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-23 0:59 Preferred OS, processor family for running embedded Ada? Mike Silva
2007-02-23 4:41 ` Steve
2007-02-23 16:00 ` Mike Silva
2007-02-23 4:49 ` Jeffrey R. Carter
2007-02-23 13:13 ` Mike Silva
2007-02-23 13:56 ` Stephen Leake
2007-02-23 14:10 ` Mike Silva
2007-02-24 10:45 ` Stephen Leake
2007-02-24 12:27 ` Jeffrey Creem
2007-02-24 22:10 ` Dr. Adrian Wrigley
2007-02-25 13:10 ` roderick.chapman
2007-02-25 17:53 ` Jeffrey R. Carter
2007-02-25 15:08 ` Stephen Leake
2007-02-28 17:20 ` Embedded languages based on early Ada (from "Re: Preferred OS, processor family for running embedded Ada?") Colin Paul Gloster
2007-03-01 9:18 ` Jean-Pierre Rosen
2007-03-01 11:22 ` Dr. Adrian Wrigley
2007-03-01 11:47 ` claude.simon
2007-03-01 13:57 ` Dmitry A. Kazakov
2007-03-01 18:09 ` Ray Blaak
2007-03-02 11:36 ` Dr. Adrian Wrigley
2007-03-02 16:32 ` Dmitry A. Kazakov
2007-03-03 0:00 ` Dr. Adrian Wrigley
2007-03-03 11:00 ` Dmitry A. Kazakov
2007-03-03 11:27 ` Jonathan Bromley
2007-03-03 12:12 ` Simon Farnsworth
2007-03-03 14:07 ` Dr. Adrian Wrigley
2007-03-03 17:28 ` Pascal Obry
2007-03-03 18:11 ` Dmitry A. Kazakov
2007-03-03 18:31 ` Pascal Obry
2007-03-03 20:26 ` Dmitry A. Kazakov
2007-03-03 21:28 ` Dr. Adrian Wrigley
2007-03-03 22:00 ` Pascal Obry
2007-03-03 13:40 ` Dr. Adrian Wrigley
2007-03-03 15:26 ` Jonathan Bromley
2007-03-03 16:59 ` Dr. Adrian Wrigley
2007-03-05 15:36 ` Colin Paul Gloster
2007-03-03 1:58 ` Ray Blaak
2007-03-03 8:14 ` Pascal Obry
2007-03-03 11:00 ` Dmitry A. Kazakov
2007-03-03 21:13 ` Ray Blaak
2007-03-05 19:01 ` PAR (Was: Embedded languages based on early Ada) Jacob Sparre Andersen
2007-03-06 2:01 ` Dr. Adrian Wrigley
2007-03-06 3:30 ` Randy Brukardt
2007-03-06 7:10 ` Ray Blaak
2007-03-06 18:05 ` Ray Blaak
2007-03-06 6:04 ` tmoran
2007-03-06 6:59 ` Ray Blaak
2007-03-06 7:07 ` Ray Blaak
2007-03-06 7:22 ` Martin Krischik
2007-03-06 13:18 ` Dr. Adrian Wrigley
2007-03-06 18:16 ` Ray Blaak
2007-03-06 23:49 ` Randy Brukardt
2007-03-07 8:59 ` Dmitry A. Kazakov
2007-03-07 18:26 ` Ray Blaak
2007-03-07 19:03 ` Dr. Adrian Wrigley
2007-03-07 19:55 ` Dmitry A. Kazakov
2007-03-07 20:17 ` Ray Blaak
2007-03-08 10:06 ` Dmitry A. Kazakov
2007-03-08 18:03 ` Ray Blaak
2007-03-07 20:18 ` Pascal Obry
2007-03-07 20:41 ` Dr. Adrian Wrigley
2007-03-08 5:45 ` Randy Brukardt
2007-03-08 10:06 ` Dmitry A. Kazakov
2007-03-10 1:58 ` Randy Brukardt
2007-03-10 9:11 ` Dmitry A. Kazakov
2007-03-08 18:08 ` Ray Blaak
2007-03-10 1:50 ` Randy Brukardt [this message]
2007-03-05 15:23 ` Embedded languages based on early Ada (from "Re: Preferred OS, processor family for running embedded Ada?") Colin Paul Gloster
2007-03-06 0:31 ` Dr. Adrian Wrigley
2007-03-01 16:09 ` Colin Paul Gloster
2007-03-01 13:23 ` Martin Thompson
2007-02-26 16:34 ` Preferred OS, processor family for running embedded Ada? Jean-Pierre Rosen
2007-02-26 21:18 ` Dr. Adrian Wrigley
2007-02-27 15:39 ` Jean-Pierre Rosen
2007-02-28 12:25 ` Jerome Hugues
2007-02-24 19:11 ` Mike Silva
2007-02-24 13:59 ` Jacob Sparre Andersen
2007-03-01 19:32 ` Jacob Sparre Andersen
2007-03-01 20:22 ` Mike Silva
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