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: 103376,7d5642dc1158588b X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!nntp.scarlet.biz!news.scarlet.biz.POSTED!not-for-mail NNTP-Posting-Date: Wed, 31 Jan 2007 02:12:42 -0600 From: Ludovic Brenta Newsgroups: comp.lang.ada Subject: Re: Ravenscar - program termination References: <87zm81txs1.fsf@ludovic-brenta.org> <1170167084.668967.110840@s48g2000cws.googlegroups.com> <45bf97d4$0$22524$39db0f71@news.song.fi> <45c0499c$0$22512$39db0f71@news.song.fi> Date: Wed, 31 Jan 2007 09:12:40 +0100 Message-ID: <87fy9rty13.fsf@ludovic-brenta.org> User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) Cancel-Lock: sha1:hXkcHaRzBdiJx/SIiedZUYiloRA= MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii NNTP-Posting-Host: 62.235.210.91 X-Trace: sv3-WvsIj2zaJ3DmLO1XiedsFZRHlSRJ5V0EkvvaGQLI0VlopqCn9WqBYLIyPOHbiSHidxG68TD99jzHP5v!Tch8kd7KLFcTjkUEdFjOIfcpEf6KlQEjU/nfJfkDZVQYm8sRvruR1qxG7UwqXIBLc4jwyBKe6g== X-Complaints-To: abuse@scarlet.be X-DMCA-Complaints-To: abuse@scarlet.biz X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.32 Xref: g2news2.google.com comp.lang.ada:8759 Date: 2007-01-31T09:12:40+01:00 List-Id: Niklas Holsti writes: > If Ravenscar really requires that the main procedure be > non-terminating, I'm happy to learn that. From a very formal point > of view I guess this requirement means that the kernel need not > implement "await for task termination" even in the environment task. Indeed, one of Ravenscar's goals is to make the necessary kernel easy to certify to the most stringent safety standards. As with all high-integrity software, the best way to achieve this is to make things small and simple. So, not only does Ravenscar avoid the need to wait for task termination, but also the tasking model (priority ceiling inheritance) avoids the need for locks completely. Imagine a tasking kernel with no mutexes :) Ravenscar is beautiful, IMHO. -- Ludovic Brenta.