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,e80a1497a689d8a5 X-Google-Attributes: gid103376,public From: Robert A Duff Subject: Re: Ammo-zilla Date: 1999/11/02 Message-ID: #1/1 X-Deja-AN: 543565043 Sender: bobduff@world.std.com (Robert A Duff) References: <38120FAF.945ADD7D@hso.link.com> <7uutgd$87h$1@nnrp1.deja.com> <19991024.18033546@db3.max5.com> <38189268.43EB150F@mail.earthlink.net> <86ogdjtdwz.fsf@ppp-115-70.villette.club-internet.fr> <7vadsp$8q61@news.cis.okstate.edu> <1999Oct28.221910.1@eisner> <7vb3c4$8a21@news.cis.okstate.edu> <7vhg2n$7ht$1@nnrp1.deja.com> <7vkjea$b34$1@nnrp1.deja.com> Organization: The World Public Access UNIX, Brookline, MA Newsgroups: comp.lang.ada Date: 1999-11-02T00:00:00+00:00 List-Id: Robert Dewar writes: > Well do you understand the concern? Have you done debugging in > this kind of environment? I have! Not a whole lot, but I have written mixed Smalltalk and assembly language, and yes, bugs were very nasty once in a while, because the GC destroys the evidence. But if the total amount of assembly is reasonably small, and you know you have a "weird" bug, you can stare at the assembly very carefully until you see it. Or you can set options on the GC that tell it to run more often (so you might get lucky and trip over the bug sooner), or whatever. I've also had experience with mixed Simula and Pascal, and with pure assembly with some ad hoc sort of GC of some data structures. But I've also seen some pretty nasty bugs in non-GC'ed systems, so... In any case, in a garbage-collected system, somebody has to write the garbage collector itself, and that fundamentally requires the kind of low-level features we're talking about -- the GC obviously can't rely on the existence of GC. Bugs in the GC itself have exactly the same sort of nasty consequences we're talking about. > A bug that damages the integrity of the collection mechanism can > often take many garbage collection cycles to make itself known, > spreading like a kind of cancer at each garbage collection > cycle. Furthermore, the result might just be a subtle memory > leak, particularly hard to detect, when the real reason for the > problem has been disposed of many GC cycles ago. - Bob