From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
To: Michael Haggerty <mhagger@alum.mit.edu>
Cc: "Junio C Hamano" <gitster@pobox.com>,
"Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>,
"Stefan Beller" <sbeller@google.com>, "Jeff King" <peff@peff.net>,
"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
"Brandon Williams" <bmwill@google.com>,
git@vger.kernel.org
Subject: Re: [PATCH 00/20] Read `packed-refs` using mmap()
Date: Fri, 15 Sep 2017 00:16:40 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1.1709150012550.219280@virtualbox> (raw)
In-Reply-To: <ef919cc7-7e41-afb6-38b2-e2fae4efcbf1@alum.mit.edu>
Hi Michael,
On Thu, 14 Sep 2017, Michael Haggerty wrote:
> On 09/13/2017 07:15 PM, Michael Haggerty wrote:
> > [...]
> > * `mmap()` the whole file rather than `read()`ing it.
> > [...]
>
> Apparently this doesn't work on Windows, because the `snapshot` is
> keeping the `packed-refs` file open too long, so the new file can't be
> renamed on top of it.
Indeed, I sent you a mail about it before I checked for new mails ;-)
> I didn't realize that this is even allowed, but TIL that you can close a
> file while keeping it mmapped. Does that technique work on Windows? If
> so, I'll change v2 to do it as sketched below.
I do not know whether that technique works on Windows, but it would not
solve the problem *entirely*, as I outlined in my reply: in
delete_branches(), for example, the main_worktree_ref_store is implicitly
getting its snapshot initialized, and nothing seems to release it.
This is only one example, as I figure that multiple worktrees could cause
even more ref_stores to have unreleased snapshots of the packed-refs file.
I imagine that something like close_all_packs() is needed
("clear_all_snapshots()"?).
Ciao,
Dscho
next prev parent reply other threads:[~2017-09-14 22:17 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-13 17:15 [PATCH 00/20] Read `packed-refs` using mmap() Michael Haggerty
2017-09-13 17:15 ` [PATCH 01/20] ref_iterator: keep track of whether the iterator output is ordered Michael Haggerty
2017-09-13 17:15 ` [PATCH 02/20] prefix_ref_iterator: break when we leave the prefix Michael Haggerty
2017-09-13 17:15 ` [PATCH 03/20] packed_ref_cache: add a backlink to the associated `packed_ref_store` Michael Haggerty
2017-09-13 17:15 ` [PATCH 04/20] die_unterminated_line(), die_invalid_line(): new functions Michael Haggerty
2017-09-13 17:15 ` [PATCH 05/20] read_packed_refs(): use mmap to read the `packed-refs` file Michael Haggerty
2017-09-13 17:16 ` [PATCH 06/20] read_packed_refs(): only check for a header at the top of the file Michael Haggerty
2017-09-13 17:16 ` [PATCH 07/20] read_packed_refs(): make parsing of the header line more robust Michael Haggerty
2017-09-13 17:16 ` [PATCH 08/20] read_packed_refs(): read references with minimal copying Michael Haggerty
2017-09-13 17:16 ` [PATCH 09/20] packed_ref_cache: remember the file-wide peeling state Michael Haggerty
2017-09-13 17:16 ` [PATCH 10/20] mmapped_ref_iterator: add iterator over a packed-refs file Michael Haggerty
2017-09-13 17:16 ` [PATCH 11/20] mmapped_ref_iterator_advance(): no peeled value for broken refs Michael Haggerty
2017-09-13 17:16 ` [PATCH 12/20] packed_ref_cache: keep the `packed-refs` file open and mmapped Michael Haggerty
2017-09-13 17:16 ` [PATCH 13/20] read_packed_refs(): ensure that references are ordered when read Michael Haggerty
2017-09-13 17:16 ` [PATCH 14/20] packed_ref_iterator_begin(): iterate using `mmapped_ref_iterator` Michael Haggerty
2017-09-13 17:16 ` [PATCH 15/20] packed_read_raw_ref(): read the reference from the mmapped buffer Michael Haggerty
2017-09-13 17:16 ` [PATCH 16/20] ref_store: implement `refs_peel_ref()` generically Michael Haggerty
2017-09-13 17:16 ` [PATCH 17/20] packed_ref_store: get rid of the `ref_cache` entirely Michael Haggerty
2017-09-13 17:16 ` [PATCH 18/20] ref_cache: remove support for storing peeled values Michael Haggerty
2017-09-13 17:16 ` [PATCH 19/20] mmapped_ref_iterator: inline into `packed_ref_iterator` Michael Haggerty
2017-09-13 17:16 ` [PATCH 20/20] packed-backend.c: rename a bunch of things and update comments Michael Haggerty
2017-09-13 23:00 ` Stefan Beller
2017-09-13 21:35 ` [PATCH 00/20] Read `packed-refs` using mmap() Junio C Hamano
2017-09-14 16:12 ` Michael Haggerty
2017-09-14 22:16 ` Johannes Schindelin [this message]
2017-09-14 20:23 ` Johannes Schindelin
2017-09-15 4:21 ` Michael Haggerty
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=alpine.DEB.2.21.1.1709150012550.219280@virtualbox \
--to=johannes.schindelin@gmx.de \
--cc=avarab@gmail.com \
--cc=bmwill@google.com \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
--cc=mhagger@alum.mit.edu \
--cc=pclouds@gmail.com \
--cc=peff@peff.net \
--cc=sbeller@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).