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=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!eu.feeder.erje.net!feeder.erje.net!us.feeder.erje.net!bloom-beacon.mit.edu!bloom-beacon.mit.edu!newsswitch.lcs.mit.edu!nntp.TheWorld.com!.POSTED!not-for-mail From: Robert A Duff Newsgroups: comp.lang.ada Subject: Re: confusion about message passing between the tasks Date: Sun, 26 Oct 2014 16:31:25 -0400 Organization: The World Public Access UNIX, Brookline, MA Message-ID: References: NNTP-Posting-Host: shell01.theworld.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: pcls7.std.com 1414355465 8541 192.74.137.71 (26 Oct 2014 20:31:05 GMT) X-Complaints-To: abuse@TheWorld.com NNTP-Posting-Date: Sun, 26 Oct 2014 20:31:05 +0000 (UTC) User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (irix) Cancel-Lock: sha1:QDr7wQfJO8l9AV3EC88HTFLi9VA= Xref: news.eternal-september.org comp.lang.ada:22780 Date: 2014-10-26T16:31:25-04:00 List-Id: Robert A Duff writes: > OK, then I'll make a stronger claim: Everything you can do with > rendezvous you can do with (something like) protected objects, > and do it just as cleanly, and sometimes even better. ...but the other way around isn't true. Here's Tucker's example that convinced me that some sort of "pragma Passive(Buffer_Task);" wasn't going to cut it. Write a PO a that is in one of two states, "accepting calls to Entry_1" and "accepting calls to Entry_2", never in both states at the same time, and never in neither state (as observed by callers). Pretty easy. With rendezvous, not so much. - Bob