From: Michael Haggerty <mhagger@alum.mit.edu>
To: Junio C Hamano <gitster@pobox.com>
Cc: Jeff King <peff@peff.net>, Johan Herland <johan@herland.net>,
Ramsay Jones <ramsay@ramsay1.demon.co.uk>,
git@vger.kernel.org, Michael Haggerty <mhagger@alum.mit.edu>
Subject: [PATCH v3 03/12] refs: wrap the packed refs cache in a level of indirection
Date: Thu, 20 Jun 2013 10:37:45 +0200 [thread overview]
Message-ID: <1371717474-28942-4-git-send-email-mhagger@alum.mit.edu> (raw)
In-Reply-To: <1371717474-28942-1-git-send-email-mhagger@alum.mit.edu>
As we know, we can solve any problem in this manner. In this case,
the problem is to avoid freeing a packed refs cache while somebody is
using it. So add a level of indirection as a prelude to
reference-counting the packed refs cache.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
refs.c | 32 ++++++++++++++++++++++++++------
1 file changed, 26 insertions(+), 6 deletions(-)
diff --git a/refs.c b/refs.c
index 9f1a007..373d95b 100644
--- a/refs.c
+++ b/refs.c
@@ -806,6 +806,10 @@ static int is_refname_available(const char *refname, const char *oldrefname,
return 1;
}
+struct packed_ref_cache {
+ struct ref_entry *root;
+};
+
/*
* Future: need to be in "struct repository"
* when doing a full libification.
@@ -813,7 +817,7 @@ static int is_refname_available(const char *refname, const char *oldrefname,
static struct ref_cache {
struct ref_cache *next;
struct ref_entry *loose;
- struct ref_entry *packed;
+ struct packed_ref_cache *packed;
/*
* The submodule name, or "" for the main repo. We allocate
* length 1 rather than FLEX_ARRAY so that the main ref_cache
@@ -825,7 +829,8 @@ static struct ref_cache {
static void clear_packed_ref_cache(struct ref_cache *refs)
{
if (refs->packed) {
- free_ref_entry(refs->packed);
+ free_ref_entry(refs->packed->root);
+ free(refs->packed);
refs->packed = NULL;
}
}
@@ -996,24 +1001,39 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir)
}
}
-static struct ref_dir *get_packed_refs(struct ref_cache *refs)
+/*
+ * Get the packed_ref_cache for the specified ref_cache, creating it
+ * if necessary.
+ */
+static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
{
if (!refs->packed) {
const char *packed_refs_file;
FILE *f;
- refs->packed = create_dir_entry(refs, "", 0, 0);
+ refs->packed = xcalloc(1, sizeof(*refs->packed));
+ refs->packed->root = create_dir_entry(refs, "", 0, 0);
if (*refs->name)
packed_refs_file = git_path_submodule(refs->name, "packed-refs");
else
packed_refs_file = git_path("packed-refs");
f = fopen(packed_refs_file, "r");
if (f) {
- read_packed_refs(f, get_ref_dir(refs->packed));
+ read_packed_refs(f, get_ref_dir(refs->packed->root));
fclose(f);
}
}
- return get_ref_dir(refs->packed);
+ return refs->packed;
+}
+
+static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
+{
+ return get_ref_dir(packed_ref_cache->root);
+}
+
+static struct ref_dir *get_packed_refs(struct ref_cache *refs)
+{
+ return get_packed_ref_dir(get_packed_ref_cache(refs));
}
void add_packed_ref(const char *refname, const unsigned char *sha1)
--
1.8.3.1
next prev parent reply other threads:[~2013-06-20 8:43 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 8:37 [PATCH v3 00/12] Fix some reference-related races Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 01/12] repack_without_ref(): split list curation and entry writing Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 02/12] pack_refs(): split creation of packed refs " Michael Haggerty
2013-06-20 8:37 ` Michael Haggerty [this message]
2013-06-20 8:37 ` [PATCH v3 04/12] refs: implement simple transactions for the packed-refs file Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 05/12] refs: manage lifetime of packed refs cache via reference counting Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 06/12] do_for_each_entry(): increment the packed refs cache refcount Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 07/12] packed_ref_cache: increment refcount when locked Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 08/12] Extract a struct stat_data from cache_entry Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 09/12] add a stat_validity struct Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 10/12] get_packed_ref_cache: reload packed-refs file when it changes Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 11/12] for_each_ref: load all loose refs before packed refs Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 12/12] refs: do not invalidate the packed-refs cache unnecessarily 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=1371717474-28942-4-git-send-email-mhagger@alum.mit.edu \
--to=mhagger@alum.mit.edu \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
--cc=johan@herland.net \
--cc=peff@peff.net \
--cc=ramsay@ramsay1.demon.co.uk \
/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).