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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,6ff6ac051491e437 X-Google-Attributes: gid103376,public From: "James A. Squire" Subject: Re: Question about the need for requeue as described in Rationale Date: 1996/07/08 Message-ID: <31E16C28.3BE2@csehp3.mdc.com>#1/1 X-Deja-AN: 167248162 sender: Ada programming language references: <31c8fdd4.5a455349@zesi.ruhr.de> comments: Gated by NETNEWS@AUVM.AMERICAN.EDU content-type: text/plain; charset=us-ascii organization: MDA Avionics Tools & Processes mime-version: 1.0 newsgroups: comp.lang.ada x-mailer: Mozilla 2.01 (X11; I; HP-UX A.09.01 9000/715) Date: 1996-07-08T00:00:00+00:00 List-Id: progers@ACM.ORG wrote: > Requeue is needed to deal with the difficulties associated with > "avoidance synchronization", which is the model used in Ada. > The most illustrative example IMHO is the lack > of expressive power of guard conditions in select statements: > the conditions may not refer to the formal parameters of the > accept statements they control. Thus you sometimes have to > to do two rendezvous instead of one, and this leads to a > number of other difficulties: the race conditions and potential > for abort mentioned elsewhere. How is this different from barrier conditions on protected entries and procedures? > See > > A Problem With Ada and Resource Allocation, Ada > Letters, vol. 3, no. 4 from 1984, > > or better yet, to hear how requeue works, > > Burns & Wellings' Concurrency In Ada, > Cambridge University Press, 1995 I don't have access to either of these references. Could you be a little more lucid? The thrust of what you are saying went right by me. -- James Squire MDA Avionics Tools & Processes ja_squire@csehp3.mdc.com Opinions expressed here are my own and NOT my company's "one of these days I'm going to better myself by going to Knight school" "You'll be a web knight instead of a web page!"