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 X-Google-Thread: 103376,470860aa3e635a7 X-Google-Attributes: gid103376,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news1.google.com!eweka.nl!lightspeed.eweka.nl!194.134.4.77.MISMATCH!news2.euro.net!newsfeed.stueberl.de!newsfeed01.sul.t-online.de!t-online.de!newsfeed.velia.net!noris.net!newsfeed.arcor.de!newsspool1.arcor-online.net!news.arcor.de.POSTED!not-for-mail From: "Dmitry A. Kazakov" Subject: Re: GNAT for MS Visual Studio Newsgroups: comp.lang.ada User-Agent: 40tude_Dialog/2.0.15.1 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Reply-To: mailbox@dmitry-kazakov.de Organization: cbb software GmbH References: <13duou81kg3sd1c@corp.supernews.com> <4xsl4zw3bp.fsf@hod.lan.m-e-leypold.de> <1191357491.860178.230380@22g2000hsm.googlegroups.com> <4702ADCC.7080209@obry.net> <1191439439.120567.172630@g4g2000hsf.googlegroups.com> <4703F02D.3030207@obry.net> <1191682021.844225.236870@g4g2000hsf.googlegroups.com> <4707A3D0.3070702@obry.net> <47088904.1090201@obry.net> Date: Wed, 10 Oct 2007 09:46:02 +0200 Message-ID: NNTP-Posting-Date: 10 Oct 2007 09:40:01 CEST NNTP-Posting-Host: 6198ee3c.newsspool3.arcor-online.net X-Trace: DXC=D^=QUX;B1WC0YVY]kmLTlDMcF=Q^Z^V3H4Fo<]lROoRA^;5]aA^R6>B=k>5QV`[:`H[6LHn;2LCVN7enW;^6ZC`DIXm65S@:3>O[i]bl9VYNMI X-Complaints-To: usenet-abuse@arcor.de Xref: g2news2.google.com comp.lang.ada:2401 Date: 2007-10-10T09:40:01+02:00 List-Id: On Tue, 09 Oct 2007 22:01:52 +0100, Simon Wright wrote: > The BCs had a form where each container object was constrained by (an > access to) a sharable mutex object; so you could form a group of > container objects with a common mutual exclusion mechanism. > > But the only way I could see to make this work was to grab the mutex > using an open protocol: > > grab the mutex; > manipulate the containers; > release the mutex; > > and once you've done that, there's no point in having the containers > mutex-aware -- just use the plain sort, with external mutex. Which is > why the BCs no longer have support for concurrency. I think that a potential way out could be protected actions on multiple objects. Provided, protected types were normal [tagged] types and protected entries and procedures were normal subprograms: type A is protected ...; type B is protected ...; entry Swap (X : in out A; Y : in out B); -- The primitive protected operation/entry of A and B has a queue, -- starts one protected action on both A and B, sees the members -- of both. [This requires multiple dispatch, of course] -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de