git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
From: Elijah Newren <newren@gmail.com>
To: Jeff King <peff@peff.net>
Cc: Git Mailing List <git@vger.kernel.org>,
	Derrick Stolee <dstolee@microsoft.com>
Subject: Re: [PATCH] clear_pattern_list(): clear embedded hashmaps
Date: Mon, 17 Aug 2020 10:22:27 -0700	[thread overview]
Message-ID: <CABPp-BGUBPJCW3-GrVvom5CwfauY-m5ZCLJmKP=P=fXWm=Kepg@mail.gmail.com> (raw)
In-Reply-To: <CABPp-BGrxaY-ObzuJ60TDMfQD+crq+TTnYE03T=KVmG5mEf-5A@mail.gmail.com>

On Mon, Aug 17, 2020 at 9:55 AM Elijah Newren <newren@gmail.com> wrote:
>
> Hi,
>
> On Fri, Aug 14, 2020 at 5:23 AM Jeff King <peff@peff.net> wrote:
> >
> > Commit 96cc8ab531 (sparse-checkout: use hashmaps for cone patterns,
> > 2019-11-21) added some auxiliary hashmaps to the pattern_list struct,
> > but they're leaked when clear_pattern_list() is called.
> >
> > Signed-off-by: Jeff King <peff@peff.net>
> > ---
> > I have no idea how often this leak triggers in practice. I just noticed
> > it while poking at LSan output (which we remain depressingly far
> > from getting a clean run on).
> >
> >  dir.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/dir.c b/dir.c
> > index fe64be30ed..9411b94e9b 100644
> > --- a/dir.c
> > +++ b/dir.c
> > @@ -916,6 +916,8 @@ void clear_pattern_list(struct pattern_list *pl)
> >                 free(pl->patterns[i]);
> >         free(pl->patterns);
> >         free(pl->filebuf);
> > +       hashmap_free_entries(&pl->recursive_hashmap, struct pattern_entry, ent);
> > +       hashmap_free_entries(&pl->parent_hashmap, struct pattern_entry, ent);
>
> This clears up the hash entries, but continues to leak the hash table.
> Since you submitted first, can you fix this to use hashmap_free_()
> instead, as per
> https://lore.kernel.org/git/932741d7598ca2934dbca40f715ba2d3819fcc51.1597561152.git.gitgitgadget@gmail.com/?
>  Then I'll rebase my series on yours and drop my first patch (since
> it'll then be identical).

Nevermind, I got confused once again by the name.
hashmap_free_entries() doesn't mean just free the entries, it means
free what hashmap_free() would plus all the entries, i.e. do what
hashmap_free() *should* *have* *been* defined to do.  Such a confusing
API.  And hashmap_free() really perplexes me -- it seems like a
function that can't possibly be useful; it's sole purpose seems to be
a trap for the unwary.

  reply	other threads:[~2020-08-17 17:27 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-14 11:10 Jeff King
2020-08-14 12:13 ` Derrick Stolee
2020-08-17 16:55 ` Elijah Newren
2020-08-17 17:22   ` Elijah Newren [this message]
2020-08-17 18:48     ` Jeff King

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='CABPp-BGUBPJCW3-GrVvom5CwfauY-m5ZCLJmKP=P=fXWm=Kepg@mail.gmail.com' \
    --to=newren@gmail.com \
    --cc=dstolee@microsoft.com \
    --cc=git@vger.kernel.org \
    --cc=peff@peff.net \
    --subject='Re: [PATCH] clear_pattern_list(): clear embedded hashmaps' \
    /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

Code repositories for project(s) associated with this 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).