public inbox for gcc@gcc.gnu.org
 help / color / mirror / Atom feed
From: Basile Starynkevitch <basile@starynkevitch.net>
To: gcc@gcc.gnu.org
Cc: Marc Glisse <marc.glisse@inria.fr>
Subject: Re: adding destroyable objects into Ggc
Date: Fri, 21 Oct 2011 09:03:00 -0000	[thread overview]
Message-ID: <20111021080914.08528e83f5eb53897d92fee9@starynkevitch.net> (raw)
In-Reply-To: <alpine.DEB.2.02.1110201708080.2378@laptop-mg.saclay.inria.fr>

On Thu, 20 Oct 2011 17:13:46 +0200 (CEST)
Marc Glisse <marc.glisse@inria.fr> wrote:

> Can't you use GTY-ed memory in PPL? Sorry for the naive question, but 
> std::vector can take an allocator parameter, gmp lets you specify an 
> allocation function...


I believe that the PPL C++ code don't have any kind of allocator parameters.

But I am not sure it would help. Let's take just a std::string allocated with an
allocator that would use Ggc-ed memory, and appearing inside a GTY-ed data. 
How that Ggc-ed memory used for the string will be marked, and how will it be released?

The usual way to release memory allocated by Ggc is inside ggc_collect (e.g. by
sweep_pages) and that happens when the object has not been marked (because Ggc is a
precise mark&sweep collector).

And because C++ collections don't offer (AFAIK) any support to scan all their internal
data (so if std::string implementation actually contains a pointer to some internal
buffer which would have been Ggc-allocated because the string has been created using
our putative Ggc C++ allocator) it seems to me that the only way to make it work is to
have the C++ destructor of our std::string called from inside Ggc. This is what I call
finalized objects (or destroyable objects) inside Ggc.

Or did I not understood something about your question?

Cheers  

-- 
Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359
8, rue de la Faiencerie, 92340 Bourg La Reine, France
*** opinions {are only mine, sont seulement les miennes} ***

  reply	other threads:[~2011-10-21  6:09 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-18 16:35 Basile Starynkevitch
2011-10-18 16:43 ` Duncan Sands
2011-10-18 16:53   ` Basile Starynkevitch
2011-10-18 17:11 ` Ian Lance Taylor
2011-10-18 17:14   ` Gabriel Dos Reis
2011-10-18 17:20   ` Basile Starynkevitch
2011-10-18 17:36     ` Ian Lance Taylor
2011-10-18 17:41   ` Basile Starynkevitch
2011-10-18 17:50     ` Ian Lance Taylor
2011-10-18 17:53       ` Basile Starynkevitch
2011-10-18 18:03         ` Jonathan Wakely
2011-10-18 18:11         ` Ian Lance Taylor
2011-10-18 19:41           ` Basile Starynkevitch
2011-10-18 20:52           ` Gabriel Dos Reis
2011-10-18 19:50         ` Gabriel Dos Reis
2011-10-18 23:11           ` Basile Starynkevitch
2011-10-19  0:49             ` Jonathan Wakely
2011-10-18 19:46     ` Gabriel Dos Reis
2011-10-19  6:04     ` Chiheng Xu
2011-10-19  6:08       ` Basile Starynkevitch
2011-10-19  6:43         ` Chiheng Xu
2011-10-19  6:12       ` Gabriel Dos Reis
2011-10-19  6:17         ` Basile Starynkevitch
2011-10-19  6:22         ` Chiheng Xu
     [not found]         ` <20111019080021.4e1acb3687fc8ceacc2fd7a3@starynkevitch.net>
     [not found]           ` <CAAiZkiB-aXfE8MyY_S6YvecdxgsBnuBHp3JDWx4kirVkQx8w+A@mail.gmail.com>
2011-10-19  7:41             ` Gabriel Dos Reis
2011-10-19  7:43             ` Basile Starynkevitch
2011-10-19 12:14               ` Gabriel Dos Reis
2011-10-19 13:31                 ` Duncan Sands
2011-10-19 22:19                   ` Jonathan Wakely
2011-10-19 15:06         ` David Malcolm
2011-10-20  6:03       ` Lawrence Crowl
2011-10-20  8:29         ` Basile Starynkevitch
2011-10-20  8:37           ` Marc Glisse
2011-10-20  8:38             ` Basile Starynkevitch
2011-10-20 11:57               ` Marc Glisse
2011-10-20 12:10                 ` Basile Starynkevitch
2011-10-20 15:34                   ` Marc Glisse
2011-10-21  9:03                     ` Basile Starynkevitch [this message]
2011-10-21 12:24                       ` Marc Glisse
2011-10-21 12:28                       ` Richard Guenther
2011-10-21 23:53                         ` Basile Starynkevitch
2011-10-22  1:31                           ` Gabriel Dos Reis
2011-10-22 11:20                             ` Basile Starynkevitch
2011-10-23 13:50                           ` Richard Guenther
2011-10-19 15:56     ` Laurynas Biveinis
2011-10-19 16:54       ` Basile Starynkevitch
2011-10-20  8:52         ` Laurynas Biveinis
2011-10-20 12:27           ` Basile Starynkevitch
2011-10-20 12:51             ` Andrew Haley
2011-10-20 14:07               ` Basile Starynkevitch
2011-10-20 13:10             ` Duncan Sands
2011-10-20 14:52               ` Torvald Riegel
2011-10-20 15:14             ` Jonathan Wakely
2011-10-20 15:26               ` Richard Guenther
2011-10-20 17:23               ` Basile Starynkevitch
2011-10-20 18:38                 ` Jonathan Wakely
2011-10-18 18:39 ` Jonathan Wakely
2011-10-18 18:48   ` Basile Starynkevitch
2011-10-18 19:42     ` Jonathan Wakely
2011-10-18 19:45       ` Basile Starynkevitch
2011-10-18 22:43         ` Gabriel Dos Reis
2011-10-18 21:24     ` Gabriel Dos Reis

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20111021080914.08528e83f5eb53897d92fee9@starynkevitch.net \
    --to=basile@starynkevitch.net \
    --cc=gcc@gcc.gnu.org \
    --cc=marc.glisse@inria.fr \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).