Re: [PATCH] enable a timeout for hold_lock_file_for_update
From: Denton Liu <hidden>
Date: 2019-11-18 17:57:37
Hi Martin, Thanks for the patch. I'm not too familiar with the lockfile codebase of git but here are some general comments:
Subject: [PATCH] enable a timeout for hold_lock_file_for_update
We prefer subjects in the format of "<area>: <brief subject>" so perhaps, we could rewrite this to: lockfile: learn core.filesLockTimeout configuration On Mon, Nov 18, 2019 at 02:42:17PM +0100, Martin Nicolay wrote:
The new funktion get_files_lock_timeout_ms reads the config
s/funktion/function/
core.filesLockTimeout analog get_files_ref_lock_timeout_ms.
Perhaps s/analog/similar to/ ?
This value is used in hold_lock_file_for_update instead of the fixed value 0. --- While working with complex scripts invoking git multiple times my editor (emacs with standard version control) detects the changes and apparently calls "git status". This leads to abort in "git stash". With this patch and an appropriate value core.fileslocktimeout this problem goes away. While it may be possible to patch the elisp scripts of emacs (and all other similar callers) to call "git status" with --no-optional-locks it seems to me a better approarch to solve this problem at its root: calling hold_lock_file_for_update_timeout with a timeout of 0 ms. The implementation with the function get_files_lock_timeout_ms is adopted from a similar usage of get_files_ref_lock_timeout_ms.
It might be good to include the above three paragraphs in your commit message. Not only do they describe the change but, more importantly, they describe _why_ the change is being made.
BTW: is there a way to link this version of the patch to the previous version to reduce the work for reviewers?
When you generate your patches, run git format-patch --in-reply-to=<r> -v<n> where <r> is the Message-ID of your last patch and where <n> is the version of the patch (in this case, it should've been 2 since you sent out one before).
quoted hunk ↗ jump to hunk
Documentation/config/core.txt | 6 ++++++ lockfile.c | 16 ++++++++++++++++ lockfile.h | 4 +++- 3 files changed, 25 insertions(+), 1 deletion(-)diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt index 852d2ba37a..230ea02560 100644 --- a/Documentation/config/core.txt +++ b/Documentation/config/core.txt@@ -482,6 +482,12 @@ core.packedRefsTimeout:: all; -1 means to try indefinitely. Default is 1000 (i.e., retry for 1 second). +core.filesLockTimeout:: + The length of time, in milliseconds, to retry when trying to + lock an individual file. Value 0 means not to retry at + all; -1 means to try indefinitely. Default is 0 (i.e., don't + retry at all). + core.pager:: Text viewer for use by Git commands (e.g., 'less'). The value is meant to be interpreted by the shell. The order of preferencediff --git a/lockfile.c b/lockfile.c index 8e8ab4f29f..7301f393d6 100644 --- a/lockfile.c +++ b/lockfile.c@@ -145,6 +145,22 @@ static int lock_file_timeout(struct lock_file *lk, const char *path, } } +/* + * Get timeout for hold_lock_file_for_update. + */ +long get_files_lock_timeout_ms(void) +{ + static int configured = 0; + + static int timeout_ms = 0; /* default */ + if (!configured) { + git_config_get_int("core.fileslocktimeout", &timeout_ms); + configured = 1; + } + + return timeout_ms; +} + void unable_to_lock_message(const char *path, int err, struct strbuf *buf) { if (err == EEXIST) {diff --git a/lockfile.h b/lockfile.h index 9843053ce8..a0520e6a7b 100644 --- a/lockfile.h +++ b/lockfile.h@@ -163,6 +163,8 @@ int hold_lock_file_for_update_timeout( struct lock_file *lk, const char *path, int flags, long timeout_ms); +long get_files_lock_timeout_ms(void); + /* * Attempt to create a lockfile for the file at `path` and return a * file descriptor for writing to it, or -1 on error. The flags@@ -172,7 +174,7 @@ static inline int hold_lock_file_for_update( struct lock_file *lk, const char *path, int flags) { - return hold_lock_file_for_update_timeout(lk, path, flags, 0); + return hold_lock_file_for_update_timeout(lk, path, flags, get_files_lock_timeout_ms() );
Style nit: remove the space after the function call. Thanks, Denton
} /* -- 2.13.7