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 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,52fd60a337c05842 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-06-18 08:03:33 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!canoe.uoregon.edu!hammer.uoregon.edu!skates!not-for-mail From: Stephen Leake Newsgroups: comp.lang.ada Subject: Re: The 1980 ACM Turing Award Lecture The Emperor's Old Clothes Date: 18 Jun 2002 10:56:31 -0400 Organization: NASA Goddard Space Flight Center (skates.gsfc.nasa.gov) Message-ID: References: <3D0B813A.3040204@attbi.com> <3D0BEF81.8010704@mail.com> <3D0E4184.4070207@attbi.com> <3D0E4C9B.4030202@mail.com> NNTP-Posting-Host: anarres.gsfc.nasa.gov Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: skates.gsfc.nasa.gov 1024412661 12195 128.183.220.71 (18 Jun 2002 15:04:21 GMT) X-Complaints-To: usenet@news.gsfc.nasa.gov NNTP-Posting-Date: 18 Jun 2002 15:04:21 GMT User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 Xref: archiver1.google.com comp.lang.ada:26245 Date: 2002-06-18T15:04:21+00:00 List-Id: Hyman Rosen writes: > Oh, good lord! Do you program in the real world? Yes. > In the real world, remote CORBA servers go down. I've never used a CORBA server. > In the real world, remote databse servers go down. I've never used a remote database server > Most of the time they don't, so when they do, you throw an exception > when you lose connectivity so you don't blithely ignore the problem, > but you also don't litter every step of the way with checks. Sounds like a good partial plan. How do you handle the exceptions at the top level? In the part of the real world that I work in (hard real time embedded systems), we need to show that _every_ exceptional situation has been anticipated and appropriately handled. Sometimes that means allowing for switching to redundant hardware. That will typically be a huge "mode change". It is not something that is triggered by some exception, but rather by a certain pattern of failures, possibly with confirmation by an external supervisory system (ground control, in the case of satellites). In this world, exceptions are used during the debug and test phases, and sometimes the compiler checks are turned off for the final build, because we've proven that they will never fail. -- -- Stephe