comp.lang.ada
 help / color / mirror / Atom feed
From: Simon Wright <simon@pushface.org>
Subject: Re: How would Ariane 5 have behaved if overflow checking were not turned off?
Date: Wed, 16 Mar 2011 15:08:28 +0000
Date: 2011-03-16T15:08:28+00:00	[thread overview]
Message-ID: <m239mnhzmb.fsf@pushface.org> (raw)
In-Reply-To: 4d80b13f$0$43832$c30e37c6@exi-reader.telstra.net

"robin" <robin51@dodo.com.au> writes:

> Anyone competent in real-time programming would never have let the
> software go with unhandled overflow, because such an event would
> result in failure of the mission.

The engineers, being competent in tightly-constrained real-time
programming, found that installing exception handlers cost cpu cycles
they could not afford, so looked at all the potential overflow sites and
found that _this_ one could only occur if there was a hardware
failure. Even if they had installed an exception handler, the only
proper response would have been to shutdown this node and hand over to
the alternate; and this was the action that would result from not having
an exception handler in the first place. So, after considerable thought,
they decided against having an exception handler.

Sounds like good engineering to me. 



  reply	other threads:[~2011-03-16 15:08 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-14 15:49 How would Ariane 5 have behaved if overflow checking were not turned off? Elias Salomão Helou Neto
2011-03-14 16:17 ` KK6GM
2011-03-14 19:25   ` Yannick Duchêne (Hibou57)
2011-03-14 19:28     ` Vinzent Hoefler
2011-03-14 20:28     ` KK6GM
2011-03-15  4:02       ` Yannick Duchêne (Hibou57)
2011-03-15  4:53         ` Shark8
2011-03-14 18:29 ` Vinzent Hoefler
2011-03-16 10:41   ` How would Ariane 5 have behaved if overflow checking were notturned off? robin
2011-03-16 15:16     ` Simon Wright
2011-03-17 11:48       ` robin
2011-03-16 16:58     ` Martin Krischik
2011-03-16 23:39       ` How would Ariane 5 have behaved if overflow checking werenotturned off? robin
2011-03-17 18:48         ` Vinzent Hoefler
2011-03-18 12:06         ` Alex R. Mosteo
2011-03-18 21:15           ` How would Ariane 5 have behaved if overflow checking were not turned off? robin
2011-03-20 10:42             ` Vinzent Hoefler
2011-03-20 17:06         ` How would Ariane 5 have behaved if overflow checking werenotturned off? Martin Krischik
2011-03-20 17:11         ` Martin Krischik
2011-03-20 18:10           ` Dmitry A. Kazakov
2011-03-21 13:24         ` Leif Roar Moldskred
2011-03-20 13:07       ` How would Ariane 5 have behaved if overflow checking were notturned off? Florian Weimer
2011-03-20 17:00         ` Martin Krischik
2011-03-20 20:17           ` Florian Weimer
2011-03-20 20:37             ` Vinzent Hoefler
2011-03-20 20:14         ` Vinzent Hoefler
2011-03-16 18:20     ` Vinzent Hoefler
2011-03-16 18:29       ` Hyman Rosen
2011-03-16 18:55         ` Vinzent Hoefler
2011-03-16 19:40         ` KK6GM
2011-03-16 20:52           ` Hyman Rosen
2011-03-16 21:02             ` KK6GM
2011-03-16 21:09             ` Shark8
2011-03-16 21:13               ` Hyman Rosen
2011-03-16 21:35                 ` Shark8
2011-03-16 22:27             ` Vinzent Hoefler
2011-03-16 21:04           ` Shark8
2011-03-16 21:10             ` Hyman Rosen
2011-03-16 21:27               ` KK6GM
2011-03-16 21:31               ` Shark8
2011-03-16 22:32               ` Vinzent Hoefler
2011-03-18 21:14           ` How would Ariane 5 have behaved if overflow checking were not turned off? robin
2011-03-16 23:46       ` How would Ariane 5 have behaved if overflow checking werenotturned off? robin
2011-03-17  0:26         ` Simon Wright
2011-03-17 11:01           ` Georg Bauhaus
2011-03-17 11:04           ` robin
2011-03-17 13:36             ` Niklas Holsti
2011-03-18 21:13               ` How would Ariane 5 have behaved if overflow checking were not turned off? robin
2011-03-19 10:12                 ` Niklas Holsti
2011-03-17 22:51         ` How would Ariane 5 have behaved if overflow checking werenotturned off? Vinzent Hoefler
2011-03-18 21:13           ` How would Ariane 5 have behaved if overflow checking were not turned off? robin
2011-03-20 10:42             ` Vinzent Hoefler
2011-03-15  6:28 ` Stephen Leake
2011-03-15 17:32   ` Keith Thompson
2011-03-15 17:40     ` KK6GM
2011-03-15 19:44     ` Robert A Duff
2011-03-15 19:12   ` Florian Weimer
2011-03-15 19:45     ` KK6GM
2011-03-15 19:57     ` Vinzent Hoefler
2011-03-20 13:00       ` Florian Weimer
2011-03-20 20:13         ` Vinzent Hoefler
2011-03-15 19:42   ` John B. Matthews
2011-03-17 11:44   ` robin
2011-03-17 18:37     ` Vinzent Hoefler
2011-03-17 23:04       ` How would Ariane 5 have behaved if overflow checking were notturned off? robin
2011-03-18 15:55         ` Vinzent Hoefler
2011-03-17 21:37     ` How would Ariane 5 have behaved if overflow checking were not turned off? Vinzent Hoefler
2011-03-16 10:33 ` robin
2011-03-16 15:08   ` Simon Wright [this message]
2011-03-17 12:39     ` robin
2011-03-17 13:41       ` Georg Bauhaus
2011-03-17 23:34         ` How would Ariane 5 have behaved if overflow checking were notturned off? robin
2011-03-18 12:57           ` Hyman Rosen
2011-03-18 16:49             ` KK6GM
2011-03-18 17:18               ` Dmitry A. Kazakov
2011-03-19 17:55                 ` Keith Thompson
2011-03-20 18:39                   ` Robert A Duff
2011-03-17 18:43       ` How would Ariane 5 have behaved if overflow checking were not turned off? Vinzent Hoefler
2011-03-17 20:58       ` Simon Wright
replies disabled

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox