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,e447f17ef3e0aaf3
X-Google-Attributes: gida07f3367d7,public,usenet
X-Google-NewGroupId: yes
X-Google-Language: ENGLISH,ASCII-7-bit
Received: by 10.224.209.202 with SMTP id gh10mr241122qab.2.1344262847872;
        Mon, 06 Aug 2012 07:20:47 -0700 (PDT)
Received: by 10.180.75.8 with SMTP id y8mr1178391wiv.4.1344262847784;
        Mon, 06 Aug 2012 07:20:47 -0700 (PDT)
Path: 
 c6ni60393021qas.0!nntp.google.com!r1no7208513qas.0!news-out.google.com!n2ni72434332win.0!nntp.google.com!volia.net!news2.volia.net!feed-A.news.volia.net!border1.nntp.ams2.giganews.com!border2.nntp.ams2.giganews.com!border4.nntp.ams.giganews.com!border2.nntp.ams.giganews.com!nntp.giganews.com!news.panservice.it!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!npeer02.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!nx02.iad01.newshosting.com!newshosting.com!news-out.readnews.com!transit3.readnews.com!panix!newsfeed-00.mathworks.com!nntp.TheWorld.com!.POSTED!not-for-mail
From: Robert A Duff <bobduff@shell01.TheWorld.com>
Newsgroups: comp.lang.ada
Subject: Re: Emulating placement new
Date: Sun, 29 Jul 2012 15:14:57 -0400
Organization: The World Public Access UNIX, Brookline, MA
Message-ID: <wcca9yicrbi.fsf@shell01.TheWorld.com>
References: <87vch67jsk.fsf@mid.deneb.enyo.de>
 <wcc6296h7ua.fsf@shell01.TheWorld.com> <871uju5rq6.fsf@mid.deneb.enyo.de>
NNTP-Posting-Host: shell01.theworld.com
Mime-Version: 1.0
X-Trace: pcls6.std.com 1343589297 13883 192.74.137.71 (29 Jul 2012 19:14:57
 GMT)
X-Complaints-To: abuse@TheWorld.com
NNTP-Posting-Date: Sun, 29 Jul 2012 19:14:57 +0000 (UTC)
User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (irix)
Cancel-Lock: sha1:T5x8HrKV7N2RXqoHfyy/fFZAH5M=
X-Received-Bytes: 2127
Content-Type: text/plain; charset=us-ascii
Date: 2012-07-29T15:14:57-04:00
List-Id: <comp.lang.ada>

Florian Weimer <fw@deneb.enyo.de> writes:

> Interesting.  But think this goes into the wrong direction.  The owner
> pool still controls the allocation, Allocate_From_Subpool dispatches
> on the master pool, not the subpool.

I don't see the problem.  The allocator specifies the subpool, and
Allocate_From_Subpool takes the subpool as a parameter.  It could
dispatch on some operation of the subpool, if you want, but for
placement new, you don't even need that -- you just need the
address to allocate at.

>...So I'd still need a special
> access type type inject the owner pool.

I'm not sure what you mean.  You have to attach the "master pool"
to each access type that you want to work this way.  Is that
what you mean?

You don't need a new access type for each allocation address.
That wouldn't work anyway due to accessibility rules, which
is the weakness that subpools are trying to address.

You might also be interested in pragma Default_Storage_Pool,
which can be used to specify the pool for all access types in a
given subsystem, or (with "null") can be used to make sure
you don't forget to specify pools explicitly.

- Bob