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=0.2 required=5.0 tests=BAYES_00,INVALID_MSGID, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fac41,2c6139ce13be9980 X-Google-Attributes: gidfac41,public X-Google-Thread: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public X-Google-Thread: 1108a1,2c6139ce13be9980 X-Google-Attributes: gid1108a1,public From: Ken Garlington Subject: Re: Safety-critical development in Ada and Eiffel Date: 1997/07/17 Message-ID: <33CEA7C1.3761@flash.net>#1/1 X-Deja-AN: 257527243 References: <33CD1722.2D24@calfp.co.uk> <33CE082E.65FF@calfp.co.uk> <33CE0BB7.10CE@XYZZYcalfp.com> Organization: Flashnet Communications, http://www.flash.net Reply-To: kennieg@flash.net Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-07-17T00:00:00+00:00 List-Id: Richie Bielak wrote: > > Nick Leaton wrote: > > [...] > > > From other posters, it seems that with life critical systems (avionics) > > that this is an important consideration. Am I the only one who finds > > this worrying, that systems you have to trust depend on some calculation > > as to how the program is going to run? What happens if a new compiler > > comes out that has a different optimisation technique? > > > > I always thought it would be nice to have postconditions of the form: > > ensure > execution_time < 10 -- 10 milliseconds, let's say > > So an exception would be raised if the routine took too long > to execute. Of course, you have to decide if "execution time" includes the time for the postcondition (including any code that executes after the actual test instruction)! We usually have such measurements _outside_ the code sequence being measured (i.e., in the scheduler). > > ...richie > > -- > * richieb@XYZZYnetlabs.net - at home | Richie Bielak * > * richieb@XYZZYcalfp.com - at work | * > * Home page: http://www.netlabs.net/hp/richieb * > * "Fight software piracy, use free software!" (me) * > * (Remove XYZZY from my address before replying) *