From: Alain Frisch <alain@frisch.fr>
To: Warren Harris <warrensomebody@gmail.com>
Cc: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] RE: understanding weak
Date: Fri, 31 Oct 2008 00:06:33 +0100 [thread overview]
Message-ID: <490A3DF9.5010700@frisch.fr> (raw)
In-Reply-To: <8C745AFA-4FC2-4574-AB97-98321ECC4964@gmail.com>
Warren Harris wrote:
> On Oct 30, 2008, at 11:48 AM, CUOQ Pascal - Pascal.CUOQ@cea.fr wrote:
>> In short: don't use weak pointers to make
>> caches.
>
> Thanks for the advice -- but I thought this was exactly what weak hash
> tables were intended for.
Although there is some similarity between a weak table and a cache
("store values, but feel free to get rid of them"), they are really
different beasts: a good implementation of a weak table should release
memory as soon as possible to avoid memory leak; a good implementation
of a cache should instead keep data as long as possible (until there is
a good reason to release it, like resource exhaustion). In particular,
data stored in a OCaml weak table will be released during the next
collection cycle when it is no longer referenced by any strong
reference; this is probably not what you expect from a cache!
-- Alain
next prev parent reply other threads:[~2008-10-30 23:06 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20081030182019.EEBC5BBB7@yquem.inria.fr>
2008-10-30 18:48 ` CUOQ Pascal
2008-10-30 19:12 ` [Caml-list] " Daniel Bünzli
2008-10-30 19:35 ` Warren Harris
2008-10-30 23:06 ` Alain Frisch [this message]
2008-10-31 8:33 ` Rémi Vanicat
2008-11-01 1:08 ` [Caml-list] " Jon Harrop
2008-11-01 10:37 ` Stefano Zacchiroli
2008-11-01 15:18 ` kirillkh
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