Sujet : Re: is Vax addressing sane today
De : niklas.holsti (at) *nospam* tidorum.invalid (Niklas Holsti)
Groupes : comp.archDate : 10. Sep 2024, 19:55:37
Autres entêtes
Organisation : Tidorum Ltd
Message-ID : <lkbfgpFamojU1@mid.individual.net>
References : 1 2 3 4 5 6 7 8 9 10 11 12
User-Agent : Mozilla Thunderbird
On 2024-09-10 18:42, Anton Ertl wrote:
And it seems to me that Swift with its trapping arithmetic is a
blast from the past
The dominance of C and its descendants has corrupted the world of programming on this point. :-(
Fortunately, among up-and-coming new languages Rust is in the overflow-checking camp, at least in DEBUG-mode compilations.
(with Algol, Pascal etc. usually erroring out on overflow, and Ada raising an exception (with famously explosive consequences for the Ariane 5)),
A bit misleading, as so often when the Ariane 501 incident is brought up.
The Ariane 501 failure was a HW trap on an instruction converting a floating-point value into a 16-bit integer, not an Ada exception.
As I understand it, the analogous C code could have used the same instruction and failed in the same way (an example of Undefined Behavior)
The original designers of that Ada SW had carefully analysed the possible ranges of the numbers and correctly concluded that an overflow could not happen if the HW operated correctly. Correctly, that is, for the Ariane 4, but not for the Ariane 5 where the SW was sloppily reused through multiple process skimps and failures.
Several other similar conversions were protected with programmed range checks and suitable alternative code paths, but the analysis showed that this particular conversion did not need such checks for the Ariane 4.
One of the process failures was that the SW was never tested with the Ariane 5 launch trajectory, which would have revealed the error.
If the SW had really used Ada exceptions (difficult as the processor was
quite maxed out) a reasonable SW designer would have added an exception
handler and could have made this part of the SW fail gracefully. But
the mission would probably not have been saved because the failure investigation found other potentially fatal flaws in the systems, pointing to more process failures.
and that the trend in safe languages is to eliminate integer overflow
by allowing arbitrarily large integers.
That is not practical in a real-time, resource-limited context, at least not without a large over-provision of computing resources. And sending the resulting over-large integer to a HW register will still fail in some way if the value is too large for the HW to accept.
Date | Sujet | # | | Auteur |
5 Sep 24 | is Vax adressing sane today | 134 | | Brett |
5 Sep 24 | Re: is Vax adressing sane today | 122 | | John Dallman |
6 Sep 24 | Re: is Vax adressing sane today | 1 | | Lawrence D'Oliveiro |
6 Sep 24 | Re: is Vax adressing sane today | 120 | | Anton Ertl |
6 Sep 24 | Re: is Vax adressing sane today | 1 | | Lawrence D'Oliveiro |
6 Sep 24 | Re: is Vax adressing sane today | 5 | | MitchAlsup1 |
7 Sep 24 | Re: is Vax adressing sane today | 4 | | Anton Ertl |
7 Sep 24 | Re: is Vax adressing sane today | 3 | | Anton Ertl |
7 Sep 24 | Re: is Vax addressing sane today | 2 | | John Dallman |
7 Sep 24 | Re: is Vax addressing sane today | 1 | | Anton Ertl |
7 Sep 24 | Re: is Vax adressing sane today | 111 | | John Levine |
8 Sep 24 | Re: is Vax adressing sane today | 110 | | Anton Ertl |
8 Sep 24 | Re: is Vax adressing sane today | 102 | | MitchAlsup1 |
8 Sep 24 | Re: is Vax addressing sane today | 101 | | Lawrence D'Oliveiro |
9 Sep 24 | Re: is Vax addressing sane today | 31 | | MitchAlsup1 |
9 Sep 24 | Re: is Vax addressing sane today | 30 | | Brett |
9 Sep 24 | Re: is Vax addressing sane today | 3 | | MitchAlsup1 |
10 Sep 24 | Re: is Vax addressing sane today | 2 | | Niklas Holsti |
11 Sep 24 | Re: is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
10 Sep 24 | Re: is Vax addressing sane today | 26 | | Anton Ertl |
10 Sep 24 | Re: is Vax addressing sane today | 4 | | Michael S |
10 Sep 24 | Re: is Vax addressing sane today | 3 | | Anton Ertl |
10 Sep 24 | Re: is Vax addressing sane today | 1 | | Niklas Holsti |
11 Sep 24 | Re: is Vax addressing sane today | 1 | | Michael S |
11 Sep 24 | Re: is Vax addressing sane today | 7 | | Lawrence D'Oliveiro |
11 Sep 24 | Re: is Vax addressing sane today | 6 | | Michael S |
11 Sep 24 | Re: is Vax addressing sane today | 5 | | David Brown |
11 Sep 24 | Re: is Vax addressing sane today | 2 | | Thomas Koenig |
11 Sep 24 | Re: is Vax addressing sane today | 1 | | David Brown |
11 Sep 24 | Re: is Vax addressing sane today | 2 | | David Schultz |
13 Sep 24 | Re: is Vax addressing sane today | 1 | | David Brown |
11 Sep 24 | Re: is Vax addressing sane today | 5 | | John Levine |
11 Sep 24 | Re: is Vax addressing sane today | 4 | | Thomas Koenig |
11 Sep 24 | Re: is Vax addressing sane today | 2 | | Anton Ertl |
11 Sep 24 | Re: is Vax addressing sane today | 1 | | jseigh |
11 Sep 24 | Re: is Vax addressing sane today | 1 | | John Levine |
20 Sep20:35 | Re: is Vax addressing sane today | 9 | | Kent Dickey |
21 Sep00:00 | Re: is Vax addressing sane today | 4 | | MitchAlsup1 |
21 Sep03:09 | Re: is Vax addressing sane today | 3 | | Lawrence D'Oliveiro |
21 Sep03:52 | Re: is Vax addressing sane today | 2 | | MitchAlsup1 |
21 Sep10:17 | Re: is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
21 Sep03:12 | Re: is Vax addressing sane today | 4 | | Lawrence D'Oliveiro |
21 Sep03:51 | Re: is Vax addressing sane today | 3 | | MitchAlsup1 |
21 Sep09:56 | Re: is Vax addressing sane today | 1 | | Niklas Holsti |
21 Sep10:18 | Re: is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
9 Sep 24 | Re: is Vax addressing sane today | 69 | | Anton Ertl |
9 Sep 24 | Re: is Vax addressing sane today | 3 | | Michael S |
9 Sep 24 | Re: is Vax addressing sane today | 2 | | Anton Ertl |
9 Sep 24 | Re: is Vax addressing sane today | 1 | | Michael S |
9 Sep 24 | Re: is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
9 Sep 24 | Re: is Vax addressing sane today | 64 | | John Levine |
10 Sep 24 | Re: is Vax addressing sane today | 63 | | Anton Ertl |
10 Sep 24 | Re: is Vax addressing sane today | 62 | | Michael S |
10 Sep 24 | Re: is Vax addressing sane today | 61 | | Anton Ertl |
11 Sep 24 | Re: is Vax addressing sane today | 60 | | Lawrence D'Oliveiro |
11 Sep 24 | Re: is Vax addressing sane today | 59 | | Anton Ertl |
11 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 19 | | John Levine |
11 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 7 | | Stephen Fuld |
11 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 6 | | John Levine |
11 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 1 | | Stephen Fuld |
11 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 1 | | Thomas Koenig |
12 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 1 | | Terje Mathisen |
13 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 2 | | Lynn Wheeler |
14 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
11 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 1 | | MitchAlsup1 |
12 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 8 | | Lars Poulsen |
12 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 7 | | John Levine |
12 Sep 24 | Re: what's a mainframe | 1 | | Lars Poulsen |
12 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 5 | | Lawrence D'Oliveiro |
13 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 4 | | Terje Mathisen |
13 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 2 | | Lawrence D'Oliveiro |
13 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 1 | | Terje Mathisen |
13 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 1 | | Lynn Wheeler |
12 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
13 Sep 24 | Re: what's a mainframe, was is Vax addressing sane today | 1 | | Lynn Wheeler |
11 Sep 24 | Re: is Vax addressing sane today | 35 | | Brett |
12 Sep 24 | Re: is Vax addressing sane today | 34 | | Lawrence D'Oliveiro |
12 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 33 | | John Levine |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 6 | | Terje Mathisen |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 5 | | Thomas Koenig |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 3 | | Michael S |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 2 | | Thomas Koenig |
14 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | MitchAlsup1 |
14 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | Anton Ertl |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 23 | | Michael S |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 4 | | John Dallman |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 3 | | Michael S |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 2 | | John Dallman |
14 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 3 | | MitchAlsup1 |
14 Sep21:17 | Re: big, fast, etc, was is Vax addressing sane today | 2 | | Michael S |
14 Sep22:42 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | MitchAlsup1 |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 14 | | John Levine |
14 Sep11:21 | Re: big, fast, etc, was is Vax addressing sane today | 6 | | Anton Ertl |
14 Sep11:59 | In-memory database (was: big, fast, etc, was is Vax addressing sane today) | 5 | | Thomas Koenig |
14 Sep12:45 | Re: In-memory database (was: big, fast, etc, was is Vax addressing sane today) | 4 | | Anton Ertl |
14 Sep13:46 | Re: In-memory database (was: big, fast, etc, was is Vax addressing sane today) | 3 | | Thomas Koenig |
14 Sep14:48 | Re: In-memory database (was: big, fast, etc, was is Vax addressing sane today) | 2 | | Anton Ertl |
14 Sep15:41 | Re: In-memory database (was: big, fast, etc, was is Vax addressing sane today) | 1 | | Anton Ertl |
14 Sep11:42 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
14 Sep22:32 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | Michael S |
14 Sep22:57 | Re: big, fast, etc, was is Vax addressing sane today | 5 | | Lynn Wheeler |
14 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | Lawrence D'Oliveiro |
13 Sep 24 | Re: big, fast, etc, was is Vax addressing sane today | 1 | | Lynn Wheeler |
11 Sep 24 | Re: is Vax addressing sane today | 2 | | Stephen Fuld |
11 Sep 24 | Re: is Vax addressing sane today | 2 | | MitchAlsup1 |
8 Sep 24 | Re: is Vax adressing sane today | 7 | | Brett |
8 Sep 24 | Re: is Vax adressing sane today | 2 | | MitchAlsup1 |
6 Sep 24 | Re: is Vax adressing sane today | 2 | | MitchAlsup1 |
6 Sep 24 | Re: is Vax adressing sane today | 1 | | Lawrence D'Oliveiro |
6 Sep 24 | Re: is Vax adressing sane today | 8 | | Anton Ertl |