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-Thread: a07f3367d7,385c146dd3112519 X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII Path: g2news1.google.com!news3.google.com!feeder.news-service.com!de-l.enfer-du-nord.net!feeder2.enfer-du-nord.net!feeder1.enfer-du-nord.net!usenet-fr.net!feeder1-2.proxad.net!proxad.net!feeder1-1.proxad.net!oleane.net!oleane!hunter.axlog.fr!nobody From: Jean-Pierre Rosen Newsgroups: comp.lang.ada Subject: Re: Private or public task ? Date: Tue, 09 Feb 2010 15:26:30 +0100 Organization: Adalog Message-ID: References: <38a0a3f9-b4a0-48f3-98c9-63b03fe03aca@q4g2000yqm.googlegroups.com> NNTP-Posting-Host: mailhost.axlog.fr Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: s1.news.oleane.net 1265727285 4207 195.25.228.57 (9 Feb 2010 14:54:45 GMT) X-Complaints-To: abuse@oleane.net NNTP-Posting-Date: Tue, 9 Feb 2010 14:54:45 +0000 (UTC) User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) In-Reply-To: Xref: g2news1.google.com comp.lang.ada:9040 Date: 2010-02-09T15:26:30+01:00 List-Id: Hibou57 (Yannick Duch�ne) a �crit : > [...] > Sure a procedure of a protected type or object should be short and > quick to execute, but it seems to still remains potentially blocking. There are two kinds of blockings: bounded and unbounded. The idea is that when computing a time budget, you can account for bounded blockings, but not unbounded ones. protected procedures are bounded, because if you know the processing time and the maximum number of tasks waiting, you know the WCET of the procedure. Entries are unbounded, because they depend on a guard whose condition can be anything. The "potentially blocking" phrase should be understood as really meaning unbounded. This all boils down to: "an operation with a bounded execution time is not allowed to call an operation with an unbounded execution time". Makes more sense? -- --------------------------------------------------------- J-P. Rosen (rosen@adalog.fr) Visit Adalog's web site at http://www.adalog.fr