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: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public X-Google-Thread: fac41,2c6139ce13be9980 X-Google-Attributes: gidfac41,public X-Google-Thread: 1108a1,2c6139ce13be9980 X-Google-Attributes: gid1108a1,public From: donh@syd.csa.com.au (Don Harrison) Subject: Re: Safety-critical development in Ada and Eiffel Date: 1997/07/25 Message-ID: #1/1 X-Deja-AN: 258633069 Sender: news@syd.csa.com.au X-Nntp-Posting-Host: dev50 References: <33D6A3C4.F5F@flash.net> Organization: CSC Australia, Sydney Reply-To: donh@syd.csa.com.au Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-07-25T00:00:00+00:00 List-Id: Ken Garlington wrote: :Don Harrison wrote: :> :> Richie Bielak wrote: :> :> :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. :> :> I've also been thinking along these lines since about a year ago. It sits very :> well with DBC, IMO. : :This would work if there is an inherent time limit to the object's :functionality. :It won't work if the issue is the contribution to the object to a thread :of :execution, particularly if the object is going to support multiple :threads. :The issue of specifying absolute time in an environment where objects are :reused :in future applications is also a sticking point. ADARTS does thread :timeline :analysis independently of object interface specification, which in my :experience makes more sense. Actually, after reading more about SCOOP, I think you would probably use a different approach to implementing timed actions. You can acheive thread based timing using predefined library classes. See the discussion of class TIMED in "Object-oriented Software Construction" 2nd ed. - "A watchdog mechanism" (P. 1019) Don. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Don Harrison donh@syd.csa.com.au