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: a07f3367d7,bf608b8936d68540 X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII X-Received: by 10.180.85.134 with SMTP id h6mr12083981wiz.1.1367819136524; Sun, 05 May 2013 22:45:36 -0700 (PDT) Path: p18ni74963wiv.0!nntp.google.com!feeder1.cambriumusenet.nl!82.197.223.103.MISMATCH!feeder3.cambriumusenet.nl!feed.tweaknews.nl!194.109.133.86.MISMATCH!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!news.stack.nl!eternal-september.org!feeder.eternal-september.org!mx05.eternal-september.org!.POSTED!not-for-mail From: "J-P. Rosen" Newsgroups: comp.lang.ada Subject: Re: Accessing finalized values Date: Mon, 06 May 2013 07:45:35 +0200 Organization: A noiseless patient Spider Message-ID: References: <143a8db3-c14b-4983-a481-4b998aea42af@googlegroups.com> <7a248ba5-9fbc-4326-bbb8-eec3c125d455@googlegroups.com> Mime-Version: 1.0 Injection-Date: Mon, 6 May 2013 05:42:04 +0000 (UTC) Injection-Info: mx05.eternal-september.org; posting-host="214e2226c9a2cb4f71713357be0d6925"; logging-data="27394"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/LJ8dt6O7pLVIPQfuW0T5F" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130328 Thunderbird/17.0.5 In-Reply-To: <7a248ba5-9fbc-4326-bbb8-eec3c125d455@googlegroups.com> Cancel-Lock: sha1:Fk3vAaxfDtXSMrlfqlmUAFj0ZmU= X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Date: 2013-05-06T07:45:35+02:00 List-Id: Le 05/05/2013 17:00, sbelmont700@gmail.com a �crit : > Pathological seems like an understatement; it seems like a pretty > major catch-22. If the whole purpose of Finalize is "to ensure that > proper cleanup is performed prior to the object becoming permanently > inaccessible", but its perfectly legitimate to access the object > after Finalize has been called, then writing 110% bulletproof code > becomes much more complex. How is an object supposed to free its > resources if the resources must still be made available? > > For instance, suppose finalization for a File type closes the file; > if it has to assume that other code might call Read and Write > subprograms after Finalize has been executed, the file must stay open > and the point is moot (or it must add preconditions to every > operation). It would seem like the same rules for protected types > should apply to non-protected types as well, for all the same > reasons. >From a /language/ POV, calling a controlled object after finalization is allowed. It means that it is up to you to add checks if necessary. In your example, you would close the file in Finalize, and raise Program_Error if the local file is closed. -- J-P. Rosen Adalog 2 rue du Docteur Lombard, 92441 Issy-les-Moulineaux CEDEX Tel: +33 1 45 29 21 52, Fax: +33 1 45 29 25 00 http://www.adalog.fr