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=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,f948976d12c7ee33 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-06-23 22:22:46 PST Path: archiver1.google.com!postnews1.google.com!not-for-mail From: snarflemike@yahoo.com (Mike Silva) Newsgroups: comp.lang.ada Subject: Re: Boeing and Dreamliner Date: 23 Jun 2003 22:22:45 -0700 Organization: http://groups.google.com/ Message-ID: <20619edc.0306232122.598389dd@posting.google.com> References: <3EF5F3F3.6000806@attbi.com> NNTP-Posting-Host: 165.247.209.198 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1056432165 9196 127.0.0.1 (24 Jun 2003 05:22:45 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 24 Jun 2003 05:22:45 GMT Xref: archiver1.google.com comp.lang.ada:39633 Date: 2003-06-24T05:22:45+00:00 List-Id: Hyman Rosen wrote in message news:... > ...Pure and simple, > the Ariane 4 programmers left a buffer overflow bug in their > code, and the Ariane 5 people tripped over it. Good heavens, no, you're thinking of C! There was no buffer overflow, and there was no bug. There was a float-to-int conversion that was proven to be safe (FP value guaranteed to always fit into int) for the -4. Therefore, any conversion overflow was assumed to be caused by a sensor/hardware problem and thus programmed by intention to shut down the SDI and let the backup system take over. There is no way I can imagine that the -4 people can be accused of leaving a bug in the code. To me the situation is akin to correctly specifying a 5 Amp fuse in a 4 Amp circuit, then "reusing" the circuit but now pumping 10 Amps through it. When the 5A fuse blows, was that a design error in the original circuit? > The fact that it was in Ada helped not at all. True enough, even though the exception was a hardware trap that would have done the same thing regardless of language. Mike