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: 103376,e44790cdcea9da82 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!news.glorb.com!news2.telebyte.nl!border2.nntp.ams.giganews.com!border1.nntp.ams.giganews.com!nntp.giganews.com!feeder2.news.jippii.net!reader1.news.jippii.net!53ab2750!not-for-mail Message-ID: <417ABB1E.30809@nowhere.fi> From: Niklas Holsti Organization: Tidorum Ltd User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020623 Debian/1.0.0-0.woody.1 MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Problem with -gnatt References: <41769112.2080703@mailinator.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Date: Sat, 23 Oct 2004 23:12:14 +0300 NNTP-Posting-Host: 194.29.197.26 X-Complaints-To: newsmaster@saunalahti.com X-Trace: reader1.news.jippii.net 1098562337 194.29.197.26 (Sat, 23 Oct 2004 23:12:17 EEST) NNTP-Posting-Date: Sat, 23 Oct 2004 23:12:17 EEST Xref: g2news1.google.com comp.lang.ada:5664 Date: 2004-10-23T23:12:14+03:00 List-Id: Pascal Obry wrote: > "Alex R. Mosteo" writes: > > >>Whe are talking about no IO inside the protected subprograms, right? Nobody >>prevents you to use another task to do IO. Or I'm missing something? > > > Fine, and in this case you will have to leave the protected operation to let > another one send/receive the data to/from a task. So we are back to > "for a short time" :) No, the task doing the "long" protected operation can be pre-empted by a higher-priority task (that does not use the same protected object) and the pre-empting task can then do I/O, even blocking operations, as long as it does not call a blocking operation within (another) protected operation. In my experience, a largish real-time program will have tasks and protected objects at several priority levels, corresponding monotonically to a range of deadlines, and the protected operations on the less-urgent priority levels may be quite "long" compared to the "short" deadlines of the more-urgent levels. -- Niklas Holsti Tidorum Ltd niklas holsti tidorum fi . @ .