From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: Oberon and Wirthian languages
Date: Tue, 22 Apr 2014 18:30:38 -0500
Date: 2014-04-22T18:30:38-05:00 [thread overview]
Message-ID: <lj6u2u$7a9$1@loke.gir.dk> (raw)
In-Reply-To: lj4de1$jql$1@dont-email.me
"Simon Clubley" <clubley@remove_me.eisner.decus.org-Earth.UFP> wrote in
message news:lj4de1$jql$1@dont-email.me...
...
>> If the compiler accepts the pragma, then assignment to Register (as
>> opposed to
>> its components) is atomic:
>>
>> Register := (A => True, ...);
>
> Thank you. It was not at all 100% clear from the RM if Ada offered the
> _guarantee_ that if you had, say, 3 components in a record assignment
> for a atomic bitfield record, that the record assignment would be treated
> as one atomic operation instead of 3 atomic operations (one for each
> component).
It's not quite a guarentee, as it's Implementation Advice (C.6(22-23/2). The
reason for it being IA is simply that we can't use undefined terms like
"load" and "store" in normative wording. In this case, IA is actually
stronger because we can say directly what we mean without defining it
exactly. In theory, implementations are supposed to document all cases where
they do not follow Implementation Advice, so you should be able to determine
for a particular implementation as to whether it is followed.
I don't think there could be an absolute guarantee, as the idea of a load or
store might not make sense on a data-flow machine (or some other exotic
design). I would guess that implementers do this in virtually all cases. As
Jeff said, if it is really critical, you have a verify the code.
Randy.
next prev parent reply other threads:[~2014-04-22 23:30 UTC|newest]
Thread overview: 144+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-11 2:39 Heartbleed Charles H. Sampson
2014-04-11 7:59 ` Heartbleed Maciej Sobczak
2014-04-11 10:50 ` Heartbleed Pascal J. Bourguignon
2014-04-12 1:46 ` Heartbleed Charles H. Sampson
2014-04-11 12:43 ` Heartbleed kalvin.news
2014-04-11 19:33 ` Heartbleed Simon Clubley
2014-04-12 4:58 ` Heartbleed Shark8
2014-04-12 7:15 ` Heartbleed Nasser M. Abbasi
2014-04-12 9:28 ` Heartbleed Georg Bauhaus
2014-04-12 9:33 ` Heartbleed Georg Bauhaus
2014-04-12 11:42 ` Heartbleed Pascal J. Bourguignon
2014-04-12 15:37 ` Heartbleed Nasser M. Abbasi
2014-04-12 18:56 ` Heartbleed Pascal J. Bourguignon
2014-04-12 20:29 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-12 20:34 ` Heartbleed Dmitry A. Kazakov
2014-04-12 20:47 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-12 20:53 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-15 10:02 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-15 12:35 ` Heartbleed Dmitry A. Kazakov
2014-04-12 21:57 ` Heartbleed Niklas Holsti
2014-04-13 13:08 ` Heartbleed Georg Bauhaus
2014-04-13 13:55 ` Heartbleed Pascal J. Bourguignon
2014-04-13 15:13 ` Heartbleed Dennis Lee Bieber
2014-04-13 15:36 ` Heartbleed Nasser M. Abbasi
2014-04-12 18:39 ` Heartbleed Simon Wright
2014-04-12 19:15 ` Heartbleed Pascal J. Bourguignon
2014-04-12 19:18 ` Heartbleed Pascal J. Bourguignon
2014-04-12 20:40 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-12 20:44 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-12 21:31 ` Heartbleed Niklas Holsti
2014-04-12 14:58 ` Heartbleed Dennis Lee Bieber
2014-04-12 18:28 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-12 18:22 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-12 18:38 ` Heartbleed Simon Clubley
2014-04-12 20:24 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-12 21:48 ` Heartbleed Simon Clubley
2014-04-17 6:15 ` Heartbleed Jacob Sparre Andersen
2014-04-17 15:55 ` Heartbleed Shark8
2014-04-17 21:01 ` Heartbleed Simon Clubley
2014-04-17 21:51 ` Heartbleed Shark8
2014-04-17 21:54 ` Heartbleed Alan Jump
2014-04-17 22:02 ` Heartbleed Adam Beneschan
2014-04-17 22:35 ` Heartbleed Simon Clubley
2014-04-17 22:55 ` Heartbleed Jeffrey Carter
2014-04-18 8:48 ` Heartbleed Simon Clubley
2014-04-18 18:02 ` Heartbleed Jeffrey Carter
2014-04-18 20:31 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-18 23:16 ` Heartbleed Pascal J. Bourguignon
2014-04-19 18:29 ` Heartbleed Simon Clubley
2014-04-21 22:50 ` Heartbleed Randy Brukardt
2014-04-18 1:38 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-18 14:59 ` Heartbleed Nasser M. Abbasi
2014-04-18 17:12 ` Heartbleed Alan Browne
2014-04-18 17:30 ` Heartbleed J-P. Rosen
2014-04-18 18:04 ` Heartbleed Jeffrey Carter
2014-04-18 18:34 ` Heartbleed Simon Clubley
2014-04-18 20:45 ` Heartbleed Jeffrey Carter
2014-04-18 21:35 ` Heartbleed Dennis Lee Bieber
2014-04-18 22:20 ` Heartbleed Jeffrey Carter
2014-04-18 22:41 ` Heartbleed Adam Beneschan
2014-04-19 15:53 ` Heartbleed Dennis Lee Bieber
2014-04-18 18:37 ` Heartbleed Alan Browne
2014-04-18 20:45 ` Heartbleed Jeffrey Carter
2014-04-18 21:06 ` Heartbleed Alan Browne
2014-04-18 22:20 ` Heartbleed Jeffrey Carter
2014-04-19 14:04 ` Heartbleed Alan Browne
2014-04-18 20:49 ` Heartbleed Shark8
2014-04-18 21:07 ` Heartbleed Alan Browne
2014-04-18 22:56 ` Heartbleed Nasser M. Abbasi
2014-04-19 4:27 ` Heartbleed tmoran
2014-04-18 21:17 ` Heartbleed Shark8
2014-04-19 18:59 ` Heartbleed Simon Clubley
2014-04-19 19:21 ` Heartbleed Shark8
2014-04-18 1:29 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-18 10:42 ` Heartbleed J-P. Rosen
2014-04-19 11:50 ` Oberon and Wirthian languages (was: Heartbleed) Ludovic Brenta
2014-04-19 12:46 ` Oberon and Wirthian languages Georg Bauhaus
2014-04-19 19:17 ` Simon Clubley
2014-04-19 19:25 ` Shark8
2014-04-19 16:35 ` Oberon and Wirthian languages (was: Heartbleed) Yannick Duchêne (Hibou57)
2014-04-19 19:32 ` Simon Clubley
2014-04-19 22:30 ` Dennis Lee Bieber
2014-04-19 22:35 ` Oberon and Wirthian languages Alan Browne
2014-04-19 16:53 ` Georg Bauhaus
2014-04-19 17:32 ` Simon Wright
2014-04-19 17:35 ` Jeffrey Carter
2014-04-19 18:06 ` Yannick Duchêne (Hibou57)
2014-04-19 18:53 ` Shark8
2014-04-19 20:08 ` Simon Clubley
2014-04-19 22:16 ` Simon Clubley
2014-04-21 13:06 ` Oberon and Wirthian languages (was: Heartbleed) Simon Clubley
2014-04-21 18:13 ` Simon Clubley
2014-04-21 18:45 ` Oberon and Wirthian languages Shark8
2014-04-21 23:26 ` Randy Brukardt
2014-04-22 0:21 ` Simon Clubley
2014-04-22 5:48 ` Shark8
2014-04-21 18:16 ` Jeffrey Carter
2014-04-22 0:34 ` Simon Clubley
2014-04-22 3:01 ` Jeffrey Carter
2014-04-22 23:31 ` Randy Brukardt
2014-04-22 6:41 ` Simon Wright
2014-04-22 12:25 ` Simon Clubley
2014-04-22 19:13 ` Niklas Holsti
2014-04-22 20:46 ` Simon Clubley
2014-04-22 23:38 ` Randy Brukardt
2014-04-23 12:16 ` Simon Clubley
2014-04-23 20:55 ` Simon Wright
2014-04-24 0:20 ` Simon Clubley
2014-04-24 13:05 ` Niklas Holsti
2014-04-24 18:51 ` Simon Clubley
2014-04-24 20:11 ` Niklas Holsti
2014-04-25 1:37 ` Randy Brukardt
2014-04-25 21:33 ` Simon Clubley
2014-04-25 21:55 ` Randy Brukardt
2014-04-25 23:16 ` Dennis Lee Bieber
2014-04-26 6:31 ` Niklas Holsti
2014-04-26 0:23 ` Nasser M. Abbasi
2014-04-26 2:46 ` Shark8
2014-04-26 2:52 ` Shark8
2014-04-26 6:37 ` Niklas Holsti
2014-04-26 6:19 ` Georg Bauhaus
2014-04-26 6:35 ` Georg Bauhaus
2014-04-26 6:42 ` Niklas Holsti
2014-04-26 17:15 ` Simon Clubley
2014-04-26 6:29 ` Niklas Holsti
2014-04-26 7:36 ` Dmitry A. Kazakov
2014-04-26 7:52 ` Georg Bauhaus
2014-04-26 8:09 ` Dmitry A. Kazakov
2014-04-26 18:32 ` Simon Clubley
2014-05-08 2:36 ` Randy Brukardt
2014-05-08 17:48 ` Niklas Holsti
2014-05-08 19:22 ` Randy Brukardt
2014-04-26 7:23 ` Simon Wright
2014-04-26 9:27 ` Niklas Holsti
2014-04-26 12:34 ` Simon Wright
2014-04-27 10:38 ` Simon Wright
2014-04-27 15:36 ` Simon Clubley
2014-04-27 14:26 ` Brian Drummond
2014-04-22 23:30 ` Randy Brukardt [this message]
2014-04-23 12:17 ` Simon Clubley
2014-05-14 9:39 ` Heartbleed gvdschoot
2014-04-12 22:01 ` Heartbleed Yannick Duchêne (Hibou57)
2014-04-18 17:58 ` Heartbleed Alan Browne
2014-04-18 17:24 ` Heartbleed - attacks? Alan Browne
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