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=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: STM32F4 Discovery, communication and libraries Date: Fri, 29 Aug 2014 09:34:06 +0200 Organization: cbb software GmbH Message-ID: <1ibla8yyj3ibm$.1lz0cmeu8ptp2.dlg@40tude.net> References: <60a42dc6-d8d0-4432-ae5a-86de18b82840@googlegroups.com> <5kkrv9hejn2qhdckkeo8lidkbh3bkme1gn@4ax.com> <5b91313c-acf9-4a6e-b157-6ba7c8021567@googlegroups.com> <0513ad07-6fbe-463a-be6f-097cd5113f52@googlegroups.com> <4f1ec65a-d66a-40bf-a0d6-278fde206e70@googlegroups.com> <1cd027f2-a0e0-4206-b989-4aed2090cde8@googlegroups.com> Reply-To: mailbox@dmitry-kazakov.de NNTP-Posting-Host: yj8+JIQUMOEawvIM7K49kA.user.speranza.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: 40tude_Dialog/2.0.15.1 X-Notice: Filtered by postfilter v. 0.8.2 Xref: news.eternal-september.org comp.lang.ada:21975 Date: 2014-08-29T09:34:06+02:00 List-Id: On Thu, 28 Aug 2014 13:34:58 -0700 (PDT), embeddedrelatedmike@scriptoriumdesigns.com wrote: > On Thursday, August 28, 2014 1:09:05 PM UTC-7, Dmitry A. Kazakov wrote: >> Not really. OS is more than tasking, it is also a queueing mechanism, which >> allows waiting for I/O completion in one task without blocking all other >> tasks. >> ...... >> You could not implement an equivalent of I/O queueing under the Ravenscar >> constraints. > > Are you saying that a full Ada implementation on bare metal could not > implement an equivalent of I/O queueing? You could, but that would be equivalent to writing a small OS. > Or are you saying that Ravenscar tasking on bare metal could not implement > such queueing? Ravenscar tasking profile has serious constraints preventing this. The nature of the constraints is to statically ensure schedulability. Asking that much you must pay the price... -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de