From: Simon Wright <simon@pushface.org>
Subject: Re: Ada in command / control systems
Date: Wed, 06 Mar 2019 12:04:57 +0000
Date: 2019-03-06T12:04:57+00:00 [thread overview]
Message-ID: <ly7edcgqdy.fsf@pushface.org> (raw)
In-Reply-To: q5o00l$1gnh$1@gioia.aioe.org
"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
> On 2019-03-06 08:26, G. B. wrote:
>> Niklas Holsti <niklas.holsti@tidorum.invalid> wrote:
>>
>>> The design pictures that are really useful for understanding a piece
>>> of SW are almost always abstractions and simplifications and could
>>> be called "useful lies". Unfortunately this means that the pictures
>>> must be manually created, and manually maintained as the SW evolves.
>>
>> I like to think that there are “almost-pictures”. When I want to
>> understand a concurrent Ada program, then this may require knowing
>> the communications while keeping in mind the shared resources. For
>> understanding communications, Ada offers some visual(!) clues: e.g.,
>> the control structure of a task body together with „accept“ and
>> “requeue”. There may be “select” at the other end. These appear(!) in
>> predictable places, shaped by syntax and style(!). That’s the start
>> of a picture . And it’s abstraction, since presumably I shouldn’t
>> need to study most of the details in between the visual clues. Call
>> the result semantic folding that focuses on communications.
>
> You refer more or less the UML sequence diagram here.
>
> The problem with this sort of pictures is its literality. They
> represent an instance of task communication and not communication in
> its entirety as an abstraction of multitude of possible communication
> instances.
I once bought "System Design with Ada", R J A Buhr, Prentice Hall 1984,
for a lot of money (at the time), which I deeply regretted. He had a
diagrammatic notation for every possible mode of operation of a task
entry or a select statement. And more. The thing was, you might as well
have read/written the Ada.
next prev parent reply other threads:[~2019-03-06 12:04 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-25 6:51 Ada in command / control systems Jesper Quorning
2019-02-25 8:24 ` Dmitry A. Kazakov
2019-02-25 9:44 ` Jesper Quorning
2019-02-25 15:54 ` Dmitry A. Kazakov
2019-02-25 13:50 ` russ lyttle
2019-02-25 14:29 ` gautier_niouzes
2019-02-25 15:25 ` Simon Wright
2019-02-25 19:21 ` russ lyttle
2019-02-26 4:50 ` J-P. Rosen
2019-02-26 15:50 ` Simon Wright
2019-02-26 22:10 ` lyttlec
2019-02-26 22:39 ` Niklas Holsti
2019-02-26 23:09 ` Simon Wright
2019-02-27 13:22 ` russ lyttle
2019-02-27 14:17 ` Niklas Holsti
2019-02-27 17:49 ` russ lyttle
2019-02-25 19:53 ` Tero Koskinen
2019-02-25 20:15 ` russ lyttle
2019-03-01 14:56 ` fabien.chouteau
2019-03-01 16:58 ` Simon Wright
2019-03-01 21:19 ` russ lyttle
2019-03-01 22:32 ` fabien.chouteau
2019-03-01 23:24 ` russ lyttle
2019-02-25 21:18 ` Jesper Quorning
2019-02-26 9:28 ` Maciej Sobczak
2019-02-26 11:01 ` Dmitry A. Kazakov
2019-02-26 21:25 ` Maciej Sobczak
2019-02-27 9:33 ` Dmitry A. Kazakov
2019-02-27 20:46 ` Maciej Sobczak
2019-02-27 21:55 ` Dmitry A. Kazakov
2019-02-28 13:12 ` Maciej Sobczak
2019-02-28 17:43 ` Dmitry A. Kazakov
2019-03-01 9:22 ` Maciej Sobczak
2019-03-01 10:46 ` Dmitry A. Kazakov
2019-03-04 7:03 ` Maciej Sobczak
2019-03-04 14:38 ` Dmitry A. Kazakov
2019-03-05 9:33 ` Maciej Sobczak
2019-03-05 16:09 ` Dmitry A. Kazakov
2019-03-06 9:05 ` Maciej Sobczak
2019-03-06 14:14 ` Dmitry A. Kazakov
2019-03-07 7:02 ` Maciej Sobczak
2019-03-07 9:25 ` Dmitry A. Kazakov
2019-03-08 7:19 ` Maciej Sobczak
2019-03-08 11:08 ` Dmitry A. Kazakov
2019-03-08 17:00 ` Simon Wright
2019-03-08 17:38 ` Dmitry A. Kazakov
2019-03-05 7:18 ` G. B.
2019-03-05 9:28 ` Dmitry A. Kazakov
2019-03-05 9:51 ` Maciej Sobczak
2019-03-05 16:15 ` Dmitry A. Kazakov
2019-03-06 22:02 ` Randy Brukardt
2019-03-05 17:55 ` Niklas Holsti
2019-03-05 21:06 ` Simon Wright
2019-03-06 7:26 ` G. B.
2019-03-06 8:22 ` Dmitry A. Kazakov
2019-03-06 12:04 ` Simon Wright [this message]
2019-03-07 7:35 ` G. B.
2019-03-07 9:25 ` Dmitry A. Kazakov
2019-03-06 9:17 ` Maciej Sobczak
2019-03-08 22:45 ` russ lyttle
2019-03-09 8:16 ` Simon Wright
2019-03-09 8:59 ` Dmitry A. Kazakov
2019-03-09 18:47 ` russ lyttle
2019-03-09 20:06 ` G.B.
2019-03-09 20:38 ` Dmitry A. Kazakov
2019-03-09 18:34 ` russ lyttle
2019-03-09 19:28 ` Simon Wright
2019-03-10 21:13 ` lyttlec
2019-03-11 8:56 ` Simon Wright
2019-03-11 14:27 ` russ lyttle
2019-03-11 17:01 ` Simon Wright
2019-03-11 21:55 ` russ lyttle
2019-03-05 11:59 ` russ lyttle
2019-03-05 18:18 ` Dmitry A. Kazakov
2019-03-06 2:01 ` lyttlec
2019-03-06 8:29 ` Dmitry A. Kazakov
2019-02-26 15:54 ` Simon Wright
2019-02-26 21:43 ` Maciej Sobczak
2019-02-26 22:45 ` Simon Wright
2019-02-27 8:41 ` Dmitry A. Kazakov
2019-02-27 20:55 ` Maciej Sobczak
2019-02-27 21:26 ` Simon Wright
2019-02-27 22:08 ` Dmitry A. Kazakov
2019-02-27 11:04 ` Jesper Quorning
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