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,ba6120170d8e7faf X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-12-06 17:04:41 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!cyclone2.usenetserver.com!usenetserver.com!news01.optonline.net!news02.optonline.net.POSTED!not-for-mail From: "annonymous" Newsgroups: comp.lang.ada References: <3C0D536C.2E059EE8@computer.org> <0CdP7.48989$xS6.81382@www.newsranger.com> <3C0E5927.5657963A@baesystems.com> <3C0F7B36.52960668@computer.org> <3C0FE2DE.4BD905B9@computer.org> Subject: Re: Worst Case Execution Time Tool? X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.00.2919.6700 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6700 Message-ID: <3xUP7.13027$MX1.4207968@news02.optonline.net> Date: Fri, 07 Dec 2001 01:00:47 GMT NNTP-Posting-Host: 24.45.230.132 X-Trace: news02.optonline.net 1007686847 24.45.230.132 (Thu, 06 Dec 2001 20:00:47 EST) NNTP-Posting-Date: Thu, 06 Dec 2001 20:00:47 EST Organization: Optimum Online Xref: archiver1.google.com comp.lang.ada:17549 Date: 2001-12-07T01:00:47+00:00 List-Id: Ted writes: > In most cases there is a smaller "worst case" available, but you have to know a > fair bit about the system to know what it is. For my real-time scheduler > example, it could be that the list is implemented in an array with a hard limit > of 40 items, and it wouldn't be too horribly dificult for a code analyzer to > figure that out (although not trivial). On the other hand, it could be that the > limit is the number of items listed in a configuration file that is read in at > runtime. There's no possible way a tool could figure that out, because it isn't > really set at all. There are many cases where it may be necessary to supply guidance to the timing tools in the form of annotations. As long as the tool can identify these or they are easy to spot by huge variations between measured and theoretical times it is usually not difficult for the systems engineer to supply the constraints needed to do WCET analysis. The tool needs to be able to accept this information information in the some form that can be correlated with the program (usually specialized comments). -Tom