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: 103376,21960280f1d61e84 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Newsgroups: comp.lang.ada Subject: Re: GC in Ada References: <1169636785.504223.139630@j27g2000cwj.googlegroups.com> <45b8361a_5@news.bluewin.ch> <3pejpgfbki.fsf@hod.lan.m-e-leypold.de> <45c99c24$1@news.post.ch> <45c9bdb8$1@news.post.ch> From: Markus E Leypold Organization: N/A Date: Wed, 07 Feb 2007 13:22:09 +0100 Message-ID: User-Agent: Some cool user agent (SCUG) Cancel-Lock: sha1:nXhjC2DRZPFcvXxJHxIMD60u2jE= MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii NNTP-Posting-Host: 88.72.241.241 X-Trace: news.arcor-ip.de 1170850622 88.72.241.241 (7 Feb 2007 13:17:02 +0200) X-Complaints-To: abuse@arcor-ip.de Path: g2news2.google.com!news4.google.com!news1.google.com!news2.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!newsfeed00.sul.t-online.de!newsfeed01.sul.t-online.de!t-online.de!newsfeed.arcor-ip.de!news.arcor-ip.de!not-for-mail Xref: g2news2.google.com comp.lang.ada:9110 Date: 2007-02-07T13:22:09+01:00 List-Id: Martin Krischik writes: > Maciej Sobczak schrieb: >> Martin Krischik wrote: >> >>>> What I'm against is a GC "paradigm" that prevents me from having >>>> deterministic "good bye" hooks for scoped lifetime. The problem is >>>> that most GC-oriented languages I'm aware of do have this "issue". >>> >>> But isn't that exactly what "Unchecked_Deallocation" and "pragma >>> Controlled" is all about? Has Ada - by your rationale - not got GC >>> right? >> By my rationale Ada and C++ got it perfectly right >> ([Limited_]Controlled mess aside). >> The only difference between them in this regard is that Ada >> explicitly allows GC on the low level without requiring it (so that >> implementations can ignore the whole idea) and that C++ is >> traditionally silent about the concept altogether (so that >> implementations can provide it). ;-) > > Only that C++ does not have pragma Controlled to switch the collector > off. And Unchecked_Deallocation should deallocate even when a > collector is present. > >> (Note that GC will likely be formalized in the upcoming C++ standard.) > > Which could solve the above. > >> My criticism is targeted at those languages which bring GC to the >> top level obstructing the visible part of the object model. > > On my Weblogic course I could not stop shaking my head about all the > problems which brings the "all is pointer" concept of Java. Fortunately you can ignore this "all is pointer" by exposing only a read-only interface to the client and leaving the rest to the GC. That feels exactly like passing records around with in, out and in/out. I don't see the problem. Not to doubt your experience on this, but just because I'm curious: Can you provide a hint or example what the problems are? Regards -- Markus