From: "Martin Ågren" <martin.agren@gmail.com>
To: Eric Sunshine <sunshine@sunshineco.com>
Cc: git@vger.kernel.org, Johannes Schindelin <johannes.schindelin@gmx.de>
Subject: Re: [PATCH] config: free resources of `struct config_store_data`
Date: Sun, 13 May 2018 11:58:36 +0200 [thread overview]
Message-ID: <cover.1526204440.git.martin.agren@gmail.com> (raw)
In-Reply-To: <CAPig+cThT3VVw75VF0wuF-yR-xbnfNOxhviYGZLAksF8HFuOGw@mail.gmail.com>
On 13 May 2018 at 10:59, Eric Sunshine <sunshine@sunshineco.com> wrote:
> On Sun, May 13, 2018 at 4:23 AM Martin Ågren <martin.agren@gmail.com> wrote:
>
>> Introduce and use a small helper function `config_store_data_clear()` to
>> plug these leaks. This should be safe. The memory tracked here is config
>> parser events. Once the users (`git_config_set_multivar_in_file_gently()`
>> and `git_config_copy_or_rename_section_in_file()` at the moment) are
>> done, no-one should be holding on to a pointer into this memory.
>
> A newcomer to this code (such as myself) might legitimately wonder why
> store->key and store->value_regex are not also being cleaned up by this
Good point. I was only concerned by the members that no-one took
responsibility for.
> function. An examination of the relevant code reveals that those structure
> members are manually (and perhaps tediously) freed already by
> git_config_set_multivar_in_file_gently(), however, if
> config_store_data_clear() was responsible for freeing them, then
> git_config_set_multivar_in_file_gently() could be made a bit less noisy.
Yes, that's true.
> On the other hand, if there's actually a good reason for
> config_store_data_clear() not freeing those members, then perhaps it
> deserves an in-code comment explaining why they are exempt.
Not any good reason that I can think of, other than "history". But to be
clear, a day ago I was as much of a newcomer in this part of the code as
you are. Johannes is the one who might have the most up-to-date
understanding of this.
How about the following two patches as patches 2/3 and 3/3? I would also
need to mention in the commit message of this patch (1/3) that the
function will soon learn to clean up more members.
I could of course squash the three patches into one, but there is some
minor trickery involved, like we can't reuse a pointer in one place, but
need to xstrdup it.
Thank you for your comments. I'd be very interested in your thoughts on
this.
Martin
Martin Ågren (2):
config: let `config_store_data_clear()` handle `value_regex`
config: let `config_store_data_clear()` handle `key`
config.c | 26 ++++++++------------------
1 file changed, 8 insertions(+), 18 deletions(-)
--
2.17.0.583.g9a75a153ac
next prev parent reply other threads:[~2018-05-13 9:58 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-13 8:23 [PATCH] config: free resources of `struct config_store_data` Martin Ågren
2018-05-13 8:59 ` Eric Sunshine
2018-05-13 9:58 ` Martin Ågren [this message]
2018-05-13 9:58 ` [PATCH 2/1] config: let `config_store_data_clear()` handle `value_regex` Martin Ågren
2018-05-14 3:05 ` Eric Sunshine
2018-05-20 10:50 ` [PATCH] regex: do not call `regfree()` if compilation fails Martin Ågren
2018-05-21 18:43 ` Stefan Beller
2018-05-22 2:20 ` Eric Sunshine
2018-05-22 11:00 ` Martin Ågren
2018-05-13 9:58 ` [PATCH 3/1] config: let `config_store_data_clear()` handle `key` Martin Ågren
2018-05-14 3:03 ` [PATCH] config: free resources of `struct config_store_data` Eric Sunshine
2018-05-20 10:42 ` [PATCH v2 0/3] " Martin Ågren
2018-05-20 10:42 ` [PATCH v2 1/3] " Martin Ågren
2018-05-20 10:42 ` [PATCH v2 2/3] config: let `config_store_data_clear()` handle `value_regex` Martin Ågren
2018-05-20 10:42 ` [PATCH v2 3/3] config: let `config_store_data_clear()` handle `key` Martin Ågren
2018-05-23 7:03 ` Eric Sunshine
2018-05-23 7:01 ` [PATCH v2 0/3] config: free resources of `struct config_store_data` Eric Sunshine
2018-05-13 18:40 ` [PATCH] " Martin Ågren
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