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,e81fd3a32a1cacd2 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!wns14feed!worldnet.att.net!attbi_s22.POSTED!53ab2750!not-for-mail From: "Jeffrey R. Carter" User-Agent: Thunderbird 1.5.0.10 (Windows/20070221) MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Arguments for single-mutex-exclusion on protected types (Was: Does Ada tasking profit from multi-core cpus?) References: <5iGLh.26236$PF.18838@attbi_s21> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Message-ID: NNTP-Posting-Host: 12.201.97.213 X-Complaints-To: abuse@mchsi.com X-Trace: attbi_s22 1174435814 12.201.97.213 (Wed, 21 Mar 2007 00:10:14 GMT) NNTP-Posting-Date: Wed, 21 Mar 2007 00:10:14 GMT Organization: AT&T ASP.att.net Date: Wed, 21 Mar 2007 00:10:14 GMT Xref: g2news1.google.com comp.lang.ada:14567 Date: 2007-03-21T00:10:14+00:00 List-Id: Randy Brukardt wrote: > > I was thinking about a solution that doesn't clutter the cliient's view of > the library with (usually) irrelevant details (such as whether the library > is implemented with protected objects). After all, information hiding is > good! If you're willing to ignore that (and you are), then it certainly is > possible. But I was thinking about a library that uses as the ceiling > whatever the highest priority it is called with: that can't be implemented > in Ada 95. (Such a library would not make anything having to do with > priorities visible.) OK. We're talking about 2 different things. > If you really care about priorities, then your solution is probably better > (it allows more analyzability). Which just demonstrates that you can't just > make something "task-safe". You have to answer the question of "task-safe > for what?". And that tends to lead to families of libraries rather than an > all-in-one solution (like Ada.Containers) - or impacts reusability. Right. Concurrency adds an addition dimension. On the other hand, many multi-tasking applications I've worked on have used the PragmARCs' bounded, blocking queues, or something very like them. -- Jeff Carter "Crucifixion's a doddle." Monty Python's Life of Brian 82