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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,33802c50f0c232b9,start X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,537ae1c8878a2d6d X-Google-Attributes: gidf43e6,public From: Ken Garlington Subject: Re: Using 'C' for Safety-Critical Applications Date: 1996/12/20 Message-ID: <32BAB542.55BA@lmtas.lmco.com>#1/1 X-Deja-AN: 205116944 references: <850946828.7859.0@battery.demon.co.uk> <32B8ADF8.4F39@zip.com.au> <32B8DF3E.2F8E@ghgcorp.com> <59bq1v$287$1@nz12.rz.uni-karlsruhe.de> content-type: text/plain; charset=us-ascii organization: Lockheed Martin Tactical Aircraft Systems mime-version: 1.0 newsgroups: comp.software-eng,comp.lang.ada x-mailer: Mozilla 3.01 (Win95; U) Date: 1996-12-20T00:00:00+00:00 List-Id: ae59@rz.uni-karlsruhe.de wrote: > > I like ADA but, we have a project (safety-critical real-time system for braking) > where a small subset of C has been selected as development language just > because of commercial issues - the one and only reasons that really counts in > an industrial context!. Since Ada has been used successfully for commercial hard real-time safety-critical systems, this seems to be a silly reason. You might want to check out what your competitors are finding out. See: http://sw-eng.falls-church.va.us/AdaIC/projects/index.shtml#successes > > Those are : > o expensive runtime license of ADA compilers is an important cost constraint > for embedded application. Our application work in a very lean environment. > Most parts of the ADA runtime has been thrown away but not all. The license > has to be paid per running piece. Therefore the price per piece has been > enormously increased using ADA. Not all Ada compilers have such a pricing structure. We don't pay a per-use price for ours. Do a little comparison shopping and see if you can't get a better deal! > o runtime efficiency in size (must find place in eeproms), performance > (hard real-time application) I have a hard real-time safety-critical application running in a small EEPROM space, so this is also easily disproven. See also the Tartan comparison of Ada and C performance for TI DSPs. > o more or less the C subset left over is a replacement of Assembler, but is > sufficient to meet portability, structure, testing and certification goals Why is this an argument against using Ada? Certainly, you can create the a reasonable Ada subsset as well. If you already have working "C" code, and you're happy with it, then use it. If you're starting a new project, sounds like an excellent place to use Ada. > > Remark: > Complexity of the sources, application running certain microcontrollers: > ~4800 lines of C code > ~2500 lines of assembler > No external libraries are allowed. > > The type and the complexity of the safety critical application is probably > decisive for the selection of the programming language. Maybe C > development costs might be higher (probably during certification). But the > question is : are you cheaper than your competitor? You might also be interested in: http://sw-eng.falls-church.va.us/AdaIC/docs/reports/cada/cada_art.html > In our case, the first implementation of the system has been done in ADA - > THEN in C. Seems strange to me. If you've already made up your mind to use "C", are you just looking for someone to confirm what you've already decided? > > Kind regards > Heiner > > ------------- URL http://www.uni-karlsruhe.de/~ae59 --------------------- > Heinrich Berlejung |Institut f. Angewandte Mathematik > Tel.:+49 721 377936 / Fax:+49 721 385979 |P.O. Box 6980,D-76128 Karlsruhe > Mail:Heiner.Berlejung@math.uni-karlsruhe.de|Universitaet Karlsruhe (TH) -- LMTAS - The Fighter Enterprise - "Our Brand Means Quality" For job listings, other info: http://www.lmtas.com or http://www.lmco.com