From: Patrick Steinhardt <ps@pks.im>
To: Han-Wen Nienhuys <hanwenn@gmail.com>
Cc: "René Scharfe" <l.s.r@web.de>, "Git List" <git@vger.kernel.org>,
nasamuffin@google.com
Subject: Re: [PATCH] reftable: use xmalloc() and xrealloc()
Date: Tue, 9 Apr 2024 05:24:03 +0200 [thread overview]
Message-ID: <ZhS000b12DNoQ2pw@tanuki> (raw)
In-Reply-To: <CAOw_e7Z9dGeVU399D6o37L3am0abnYUrZnNQEFKhyUv=A2=j8g@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 2067 bytes --]
On Mon, Apr 08, 2024 at 07:50:47PM +0200, Han-Wen Nienhuys wrote:
> Op ma 8 apr 2024 07:44 schreef Patrick Steinhardt <ps@pks.im>:
> >
> > It does raise the question what to do about the generic fallbacks. We
> > could start calling `abort()` when we observe allocation failures. It's
> > not exactly nice behaviour in a library though, where the caller may in
> > fact want to handle this case. But it may at least be better than
> > failing on a `NULL` pointer exception somewhere down the road. So it
> > might be the best alternative for now. We could then conver the reftable
> > library over time to handle allocation failures and, once that's done,
> > we can eventually drop such a call to `abort()`.
>
>
> I must admit that I didn't think this part through very much; I
> believe someone told me that libgit2 has pluggable memory allocation
> routines, so I tried to make the malloc pluggable here too.
That was me probably back when I was writing the libgit2 backend.
> Handling OOM better for the malloc calls themselves doesn't seem too
> difficult,
>
> hanwen@fedora:~/vc/git/reftable$ grep [cme]alloc *c | wc
> 57 276 3469
>
> However, it is probably pointless as long as strbuf_* functions do not
> signal OOM gracefully. There was some talk of libifying strbuf. Did
> that work include returning OOM error codes in case malloc returns
> null? A quick look at strbuf.h suggests not.
Yeah, `strbuf` also crossed my mind. And there are some other systems
that the reftable library calls into, like the tempfiles framework, that
would continue to use `xmalloc()` and related functions.
> I would just call xmalloc as default, rather than calling
> reftable_set_alloc, because it might be tricky to ensure it is called
> early enough.
I don't think it should be particularly tricky to call
`reftable_set_alloc()` early enough. The reftable code won't do any
allocations before we set up the refdb. So calling this in our `main()`
function in "common-main.c" should be sufficient.
Patrick
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
prev parent reply other threads:[~2024-04-09 3:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-06 20:37 [PATCH] reftable: use xmalloc() and xrealloc() René Scharfe
2024-04-08 5:44 ` Patrick Steinhardt
2024-04-08 15:42 ` Junio C Hamano
2024-04-08 16:33 ` Patrick Steinhardt
2024-04-08 17:50 ` Han-Wen Nienhuys
2024-04-08 20:36 ` Junio C Hamano
2024-04-09 3:24 ` Patrick Steinhardt [this message]
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
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZhS000b12DNoQ2pw@tanuki \
--to=ps@pks.im \
--cc=git@vger.kernel.org \
--cc=hanwenn@gmail.com \
--cc=l.s.r@web.de \
--cc=nasamuffin@google.com \
/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.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
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).