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: backlog4.nntp.dca3.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!newspeer1.nac.net!feeder.erje.net!eu.feeder.erje.net!gandalf.srv.welterde.de!news.jacob-sparre.dk!loke.jacob-sparre.dk!pnx.dk!.POSTED!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: Safety of unprotected concurrent operations on constant objects Date: Wed, 7 May 2014 22:19:12 -0500 Organization: Jacob Sparre Andersen Research & Innovation Message-ID: References: NNTP-Posting-Host: static-69-95-181-76.mad.choiceone.net X-Trace: loke.gir.dk 1399519152 5734 69.95.181.76 (8 May 2014 03:19:12 GMT) X-Complaints-To: news@jacob-sparre.dk NNTP-Posting-Date: Thu, 8 May 2014 03:19:12 +0000 (UTC) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-RFC2646: Format=Flowed; Original X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Xref: number.nntp.dca.giganews.com comp.lang.ada:186295 Date: 2014-05-07T22:19:12-05:00 List-Id: "Natasha Kerensikova" wrote in message news:slrnlm6mkg.i0l.lithiumcat@nat.rebma.instinctive.eu... ... > Is it safe to have many tasks performing operations concurrently on > constant objects? Ada really doesn't have any such thing as constant objects for many types. The majority of "constants" of composite types are actually variables during some part of their lifetime (and because that variable view can be saved and used later, they can never be assumed to be constant). That specifically applies to anything with a controlled part and anything with an immutably limited part. As a client, since you shouldn't be looking through private types, you have to assume that there is a controlled component somewhere and thus you should never assume *anything* is constant of a private type. Ergo the question is meaningless for the vast majority of constant composite objects; they exist in name only. Randy.