From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Custom Storage Pool questions
Date: Sun, 19 Sep 2021 13:41:00 +0200 [thread overview]
Message-ID: <si77kd$rka$1@gioia.aioe.org> (raw)
In-Reply-To: iqoi4rFkbu6U1@mid.individual.net
On 2021-09-19 12:36, Niklas Holsti wrote:
> On 2021-09-18 19:19, Dmitry A. Kazakov wrote:
>> On 2021-09-18 17:59, Niklas Holsti wrote:
>>
>>> So you want a way to specify that for a given access type, although
>>> the accessed object type has a Finalize operation or needs
>>> finalization, the objects left over in the (at least conceptually)
>>> associated collection should _not_ be finalized when the scope of the
>>> access type is left?
>>
>> Exactly, especially because these objects are not deallocated, as you
>> say they are left over. If they wanted GC they should do that. If they
>> do not, then they should keep their hands off the objects maintained
>> by the programmer.
>>
>>> To me it seems a risky think to do, subverting the normal semantics
>>> of initialization and finalization.
>>
>> Quite the opposite, it is the collection rule that subverts semantics
>> because objects are not freed, yet mangled.
>
> Local variables declared in a subprogram are also not explicitly freed
> (deallocated), yet they are automatically finalized when the subprogram
> returns.
Local objects are certainly freed. Explicit or not, aggregated or not,
is irrelevant.
> My understanding of Ada semantic principles is that any object that is
> initialized should also be finalized.
IFF deallocated.
An application that runs continuously will never deallocate, HENCE
finalize certain objects.
> Has this feature of Ada caused you real problems in real applications,
> or is it only a point of principle for you?
1. It is a massive overhead in both memory and performance terms with no
purpose whatsoever. I fail to see where that sort of thing might be even
marginally useful. Specialized pools, e.g. mark-and-release will deploy
their own bookkeeping, not rely on this.
2. What is worse that a collection is not bound to the pool. It is to an
access type, which may have a narrower scope. So the user could declare
an unfortunate access type, which would corrupt objects in the pool and
the pool designer has no means to prevent that.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2021-09-19 11:41 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-13 0:53 Custom Storage Pool questions Jere
2021-09-13 5:29 ` Randy Brukardt
2021-09-14 1:04 ` Jere
2021-09-21 0:06 ` Randy Brukardt
2021-09-18 11:32 ` Simon Wright
2021-09-20 0:31 ` Jere
2021-09-20 6:34 ` Niklas Holsti
2021-09-20 6:48 ` Emmanuel Briot
2021-09-20 7:35 ` Dmitry A. Kazakov
2021-09-20 16:59 ` Shark8
2021-09-21 0:50 ` Randy Brukardt
2021-09-21 23:08 ` Jere
2021-09-28 4:42 ` Randy Brukardt
2021-10-02 23:19 ` Jere
2021-10-03 8:52 ` Dmitry A. Kazakov
2021-10-14 1:26 ` Randy Brukardt
2021-09-13 11:12 ` J-P. Rosen
2021-09-14 0:48 ` Jere
2021-09-14 6:08 ` J-P. Rosen
2021-09-15 0:39 ` Jere
2021-09-15 7:01 ` Simon Wright
2021-09-16 23:32 ` Jere
2021-09-20 23:51 ` Randy Brukardt
2021-09-21 22:40 ` Jere
2021-09-14 6:23 ` Dmitry A. Kazakov
2021-09-14 6:42 ` J-P. Rosen
2021-09-14 7:00 ` Dmitry A. Kazakov
2021-09-20 23:58 ` Randy Brukardt
2021-09-15 0:21 ` Jere
2021-09-15 6:54 ` Dmitry A. Kazakov
2021-09-20 23:48 ` Randy Brukardt
2021-09-14 10:54 ` Egil H H
2021-09-15 0:11 ` Jere
2021-09-15 16:43 ` Simon Wright
2021-09-15 17:03 ` Simon Wright
2021-09-15 19:07 ` Dmitry A. Kazakov
2021-09-15 20:40 ` Simon Wright
2021-09-16 7:12 ` Emmanuel Briot
2021-09-16 23:21 ` Jere
2021-09-17 7:08 ` Emmanuel Briot
2021-09-17 7:18 ` Simon Wright
2021-09-17 13:56 ` Dmitry A. Kazakov
2021-09-17 19:46 ` Simon Wright
2021-09-17 20:39 ` Dmitry A. Kazakov
2021-09-17 21:17 ` Niklas Holsti
2021-09-18 7:49 ` Dmitry A. Kazakov
2021-09-18 9:03 ` Niklas Holsti
2021-09-18 10:22 ` Dmitry A. Kazakov
2021-09-18 15:59 ` Niklas Holsti
2021-09-18 16:19 ` Dmitry A. Kazakov
2021-09-19 10:36 ` Niklas Holsti
2021-09-19 11:41 ` Dmitry A. Kazakov [this message]
2021-09-20 7:05 ` Niklas Holsti
2021-09-20 7:35 ` Dmitry A. Kazakov
2021-09-20 8:08 ` Niklas Holsti
2021-09-20 8:28 ` Dmitry A. Kazakov
2021-09-21 0:45 ` Randy Brukardt
2021-09-21 0:40 ` Randy Brukardt
2021-09-21 0:30 ` Randy Brukardt
2021-09-21 0:37 ` Randy Brukardt
2021-09-21 6:28 ` Dmitry A. Kazakov
2021-09-28 4:38 ` Randy Brukardt
2021-09-28 7:00 ` Dmitry A. Kazakov
2021-09-21 0:26 ` Randy Brukardt
2021-09-21 6:51 ` Dmitry A. Kazakov
2021-09-28 4:31 ` Randy Brukardt
2021-09-28 6:56 ` Dmitry A. Kazakov
2021-09-28 7:52 ` Simon Wright
2021-09-28 8:07 ` Dmitry A. Kazakov
2021-09-28 22:04 ` Randy Brukardt
2021-09-29 7:57 ` Dmitry A. Kazakov
2021-09-29 14:41 ` Shark8
2021-09-29 15:16 ` Dmitry A. Kazakov
2021-09-30 0:16 ` Randy Brukardt
2021-09-30 8:08 ` Dmitry A. Kazakov
2021-10-01 0:04 ` Randy Brukardt
2021-10-01 8:25 ` Dmitry A. Kazakov
2021-10-02 9:06 ` Randy Brukardt
2021-10-02 10:18 ` Dmitry A. Kazakov
2021-10-03 4:33 ` Randy Brukardt
2021-10-03 8:40 ` Dmitry A. Kazakov
2021-10-14 1:21 ` Randy Brukardt
2021-10-14 3:12 ` philip...@gmail.com
2021-10-14 7:31 ` Dmitry A. Kazakov
2021-10-15 0:36 ` Randy Brukardt
2021-10-15 8:08 ` Stephen Leake
2021-10-15 8:18 ` Dmitry A. Kazakov
2021-10-15 22:22 ` Randy Brukardt
2021-10-15 8:15 ` Dmitry A. Kazakov
2021-10-15 22:44 ` Randy Brukardt
2021-10-16 9:00 ` Dmitry A. Kazakov
2021-10-16 14:32 ` Simon Wright
2021-10-16 15:06 ` Dmitry A. Kazakov
2021-10-18 14:23 ` Shark8
2021-09-21 0:19 ` Randy Brukardt
2021-09-21 0:18 ` Randy Brukardt
2021-09-16 8:41 ` Dmitry A. Kazakov
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