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=-0.9 required=5.0 tests=BAYES_00,FORGED_GMAIL_RCVD, FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,bba8b62c0271070f,start X-Google-Attributes: gid103376,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!postnews.google.com!v19g2000yqn.googlegroups.com!not-for-mail From: Maciej Sobczak Newsgroups: comp.lang.ada Subject: Group execution time budgets and multicore Date: Mon, 20 Apr 2009 14:25:59 -0700 (PDT) Organization: http://groups.google.com Message-ID: <0777c8ad-1e45-4f62-829e-0e906320baa9@v19g2000yqn.googlegroups.com> NNTP-Posting-Host: 83.78.87.235 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: posting.google.com 1240262759 21430 127.0.0.1 (20 Apr 2009 21:25:59 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Mon, 20 Apr 2009 21:25:59 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: v19g2000yqn.googlegroups.com; posting-host=83.78.87.235; posting-account=bMuEOQoAAACUUr_ghL3RBIi5neBZ5w_S User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.0.8) Gecko/2009032608 Firefox/3.0.8,gzip(gfe),gzip(gfe) Xref: g2news2.google.com comp.lang.ada:5514 Date: 2009-04-20T14:25:59-07:00 List-Id: The group execution time budgets (AARM D.14.2) defines operations that allow to monitor and manage the time that is being consumed by a group of tasks. It does not, however, specify the semantics of this consumption in multiprocessor or multicore environments. Consider, for example, two tasks in a group running on a dual core machine and where the implementation can physically execute them both in parallel. Each task takes 10ms to execute. They run together, so the whole takes 10ms as well, although they are able to perform 20ms "worth" of work. What is the actual budget consumed by these two tasks? If the budget is 15ms, will it exhaust? Does D.14-22.2 (the requirement on the implementation to document the mechanisms used to measure execution times) apply here? -- Maciej Sobczak * www.msobczak.com * www.inspirel.com Database Access Library for Ada: www.inspirel.com/soci-ada