Re: [PATCH] clear_pattern_list(): clear embedded hashmaps

From: Elijah Newren <newren@gmail.com>
Date: Aug 17, 2020, 16:55 UTC
Message-ID: <CABPp-BGrxaY-ObzuJ60TDMfQD+crq+TTnYE03T=KVmG5mEf-5A@mail.gmail.com>
In-Reply-To: <20200814111049.GA4101811@coredump.intra.peff.net>

Hi,

On Fri, Aug 14, 2020 at 5:23 AM Jeff King <peff@peff.net> wrote:

Show 24 quoted lines

>
> 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).

Thanks, Elijah