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: 1108a1,2c6139ce13be9980 X-Google-Attributes: gid1108a1,public X-Google-Thread: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public From: donh@syd.csa.com.au (Don Harrison) Subject: Re: Safety-critical development in Ada and Eiffel Date: 1997/07/30 Message-ID: #1/1 X-Deja-AN: 260379317 Sender: news@syd.csa.com.au X-Nntp-Posting-Host: dev50 References: Organization: CSC Australia, Sydney Reply-To: donh@syd.csa.com.au Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-07-30T00:00:00+00:00 List-Id: Let's try this again.. Ron Kohl wrote: :Don Harrison wrote: :> :> Ken Garlington wrote: :> :> :I responded elsewhere in this thread about difficulties in trying :> :to accurately measure thread timings at the object level, :> :> As I've already explained, SCOOP *does* support thread-level timing. The fact :> this has not yet been tested in a realtime system doesn't invalidate any :> logical arguments made about it. :> : Ken's point is still valid. Yes, sorry - I was a bit blunt. I agree with Ken's statement. Unless an object corresponds directly with a thread, it isn't possible to measure thread timings at the object level. :If a 'system feature' (in this case :SCOOP's thread-level timing capability) is claimed to support hard :real-time and then this feature is implemented into a hard real-time :system and does not perform according to it's advertisement, then the :empirical data has provided a counter-example to the claims about that :feature. The point being that empirical data can either provide :examples to support theoretical claims/conjectures or it can totally :invalidate such claims if it can produce a single, valid counter :example. Absolutely! Empirical data can *disprove* a theory but not prove it. A single correctly-interpreted contrary observation is sufficient to disprove a theory whereas any number of supportive observations cannot prove it. Obviously, any number of incorrectly-interpreted contrary observations can never disprove a theory. Don. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Don Harrison donh@syd.csa.com.au -- Don. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Don Harrison donh@syd.csa.com.au