From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,ac9405996d0dcb7f X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!proxad.net!gatel-ffm!gatel-ffm!newsfeed.vmunix.org!newsfeed01.sul.t-online.de!newsmm00.sul.t-online.de!t-online.de!news.t-online.com!not-for-mail From: Martin Krischik Newsgroups: comp.lang.ada Subject: Re: Would You Fly an Airplane with a Linux-Based Control System? Date: Tue, 30 Nov 2004 14:24:54 +0100 Organization: None Message-ID: <3193657.BGZLZqeFdM@linux1.krischik.com> References: <20619edc.0411251028.3e249bf3@posting.google.com> Reply-To: martin@krischik.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit X-Trace: news.t-online.com 1101823912 05 5018 Yp78XQ7lr3pThcv 041130 14:11:52 X-Complaints-To: usenet-abuse@t-online.de X-ID: VmZ194ZGYe3jgn7gQROlalrMMcC2xvlNGe4qBVb+nzInlaJnowQqsW User-Agent: KNode/0.8.0 Xref: g2news1.google.com comp.lang.ada:6666 Date: 2004-11-30T14:24:54+01:00 List-Id: Preben Randhol wrote: > In article Marius Amado Alves wrote: >>No. This whole talk of hardware-generated exception sounds like "FUD". >>Namely, it sounds like your trying to blame the hardware. The cause was >>a SOFTWARE enginering error. Yes, a BUG. In the Ada software. And >>because it's connected to exceptions, the hypothesis that if the thing >>had been done in an exceptionless language like C the effect might have >>been different. And yes, maybe less bad. And none of the explanations >>I've seen so far (here, in books, and in the Internet) disprove this >>hypothesis. > > I'm confused. Didn't they turn off all exceptions checks? They turned of a few select runtime checks. They had proof that on an Ariane 4 they would not be needed as the Arinane 4 will never exceed the max. values. However, as Alexander pointed out, with the software checks disabled some hardware checks from the floating point unit kicked in instead and crashed the hole programm. You must understande that modern CPUs there support hardware exceptions and modern programming laguages support software exceptions. And they have nothing to do with each other. On as side note: The new M$ C and C++ compiler automaticly convert hardware exceptions into software exceptions - which I have to confess make things a lot easier. With Regards Martin -- mailto://krischik@users.sourceforge.net http://www.ada.krischik.com