Create another thread to watch over the daemon process and
automatically shut it down if necessary.
This commit creates the basic framework for a "health" thread
to monitor the daemon and/or the file system. Later commits
will add platform-specific code to do the actual work.
The "health" thread is intended to monitor conditions that
would be difficult to track inside the IPC thread pool and/or
the file system listener threads. For example, when there are
file system events outside of the watched worktree root or if
we want to have an idle-timeout auto-shutdown feature.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Rename platform-specific listener thread related variables
and data types as we prepare to add another backend thread
type.
[] `struct fsmonitor_daemon_backend_data` becomes `struct fsm_listen_data`
[] `state->backend_data` becomes `state->listen_data`
[] `state->error_code` becomes `state->listen_error_code`
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Refactor daemon thread startup to make it easier to start
a third thread class to monitor the health of the daemon.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach the fsmonitor--daemon to CD outside of the worktree
before starting up.
The common Git startup mechanism causes the CWD of the daemon process
to be in the root of the worktree. On Windows, this causes the daemon
process to hold a locked handle on the CWD and prevents other
processes from moving or deleting the worktree while the daemon is
running.
CD to HOME before entering main event loops.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach fsmonitor--daemon to print a startup message only when
`fsmonitor.announceStartup` is true. This setting is false by default
so that the output of client commands, like `git status`, is not
changed if the daemon is implicitly started.
The message is conditionally printed by "run" and "start" subcommands
and is sent to stderr. It contains the path to the work tree root.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach fsmonitor--daemon client threads to create a cookie file
inside the .git directory and then wait until FS events for the
cookie are observed by the FS listener thread.
This helps address the racy nature of file system events by
blocking the client response until the kernel has drained any
event backlog.
This is especially important on MacOS where kernel events are
only issued with a limited frequency. See the `latency` argument
of `FSeventStreamCreate()`. The kernel only signals every `latency`
seconds, but does not guarantee that the kernel queue is completely
drained, so we may have to wait more than one interval. If we
increase the frequency, the system is more likely to drop events.
We avoid these issues by having each client thread create a unique
cookie file and then wait until it is seen in the event stream.
Co-authored-by: Kevin Willford <Kevin.Willford@microsoft.com>
Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach fsmonitor--daemon to periodically truncate the list of
modified files to save some memory.
Clients will ask for the set of changes relative to a token that they
found in the FSMN index extension in the index. (This token is like a
point in time, but different). Clients will then update the index to
contain the response token (so that subsequent commands will be
relative to this new token).
Therefore, the daemon can gradually truncate the in-memory list of
changed paths as they become obsolete (older than the previous token).
Since we may have multiple clients making concurrent requests with a
skew of tokens and clients may be racing to the talk to the daemon,
we lazily truncate the list.
We introduce a 5 minute delay and truncate batches 5 minutes after
they are considered obsolete.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach fsmonitor--daemon to respond to IPC requests from client
Git processes and respond with a list of modified pathnames
relative to the provided token.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach fsmonitor--daemon to build a list of changed paths and associate
them with a token-id. This will be used by the platform-specific
backends to accumulate changed paths in response to filesystem events.
The platform-specific file system listener thread receives file system
events containing one or more changed pathnames (with whatever bucketing
or grouping that is convenient for the file system). These paths are
accumulated (without locking) by the file system layer into a `fsmonitor_batch`.
When the file system layer has drained the kernel event queue, it will
"publish" them to our token queue and make them visible to concurrent
client worker threads. The token layer is free to combine and/or de-dup
paths within these batches for efficient presentation to clients.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach fsmonitor--daemon to classify relative and absolute
pathnames and decide how they should be handled. This will
be used by the platform-specific backend to respond to each
filesystem event.
When we register for filesystem notifications on a directory,
we get events for everything (recursively) in the directory.
We want to report to clients changes to tracked and untracked
paths within the working directory. We do not want to report
changes within the .git directory, for example.
This classification will be used in a later commit by the
different backends to classify paths as events are received.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Implement 'git fsmonitor--daemon start' command. This command starts
an instance of 'git fsmonitor--daemon run' in the background using
the new 'start_bg_command()' function.
We avoid the fork-and-call technique on Unix systems in favor of a
fork-and-exec technique. This gives us more uniform Trace2 child-*
events. It also makes our usage more consistent with Windows usage.
On Windows, teach 'git fsmonitor--daemon run' to optionally call
'FreeConsole()' to release handles to the inherited Win32 console
(despite being passed invalid handles for stdin/out/err). Without
this, command prompts and powershell terminal windows could hang
in "exit" until the last background child process exited or released
their Win32 console handle. (This was not seen with git-bash shells
because they don't have a Win32 console attached to them.)
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Implement `run` command to try to begin listening for file system events.
This version defines the thread structure with a single fsmonitor_fs_listen
thread to watch for file system events and a simple IPC thread pool to
watch for connection from Git clients over a well-known named pipe or
Unix domain socket.
This commit does not actually do anything yet because the platform
backends are still just stubs.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Implement `stop` and `status` client commands to control and query the
status of a `fsmonitor--daemon` server process (and implicitly start a
server process if necessary).
Later commits will implement the actual server and monitor the file
system.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
--help and -h are already handled internally so just parse_options()
do the parsing and extract the command from the remaining options.
as a side effect, avoid setting a variable argc to a value that was
never used.
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Create a built-in file system monitoring daemon that can be used by
the existing `fsmonitor` feature (protocol API and index extension)
to improve the performance of various Git commands, such as `status`.
The `fsmonitor--daemon` feature builds upon the `Simple IPC` API and
provides an alternative to hook access to existing fsmonitors such
as `watchman`.
This commit merely adds the new command without any functionality.
Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Move FSMonitor config settings to a new `struct fsmonitor_settings`
structure. Add a lazily-loaded pointer to `struct repo_settings`.
Create `fsm_settings__get_*()` getters to lazily look up fsmonitor-
related config settings.
Get rid of the `core_fsmonitor` global variable, and add support for
the new `core.useBuiltinFSMonitor` config setting. Move config code
to lookup the existing `core.fsmonitor` value to `fsmonitor-settings.[ch]`.
The `core_fsmonitor` global variable was used to store the pathname to
the FSMonitor hook and it was used as a boolean to see if FSMonitor
was enabled. This dual usage will lead to confusion when we add
support for a builtin FSMonitor based on IPC, since the builtin
FSMonitor doesn't need the hook pathname.
Replace the boolean usage with an `enum fsmonitor_mode` to represent
the state of FSMonitor. And only set the pathname when in HOOK mode.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
We added an unrelated sanity checking that leads to a BUG() while
plugging a leak, which triggered in a repository with symrefs in
the local branch namespace that point at a ref outside. Partially
revert the change to avoid triggering the BUG().
* ab/checkout-branch-info-leakfix:
checkout: avoid BUG() when hitting a broken repository
When 9081a421 (checkout: fix "branch info" memory leaks, 2021-11-16)
cleaned up existing memory leaks, we added an unrelated sanity check
to ensure that a local branch is truly local and not a symref to
elsewhere that dies with BUG() otherwise. This was misguided in two
ways. First of all, such a tightening did not belong to a leak-fix
patch. And the condition it detected was *not* a bug in our program
but a problem in user data, where warning() or die() would have been
more appropriate.
As the condition is not fatal (the result of computing the local
branch name in the code that is involved in the faulty check is only
used as a textual label for the commit), let's revert the code to
the original state, i.e. strip "refs/heads/" to compute the local
branch name if possible, and otherwise leave it NULL. The consumer
of the information in merge_working_tree() is prepared to see NULL
in there and act accordingly.
cf. https://bugzilla.redhat.com/show_bug.cgi?id=2042920
Reported-by: Petr Šplíchal <psplicha@redhat.com>
Reported-by: Todd Zullinger <tmz@pobox.com>
Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Document that the accepted variants of the --track option are --track,
--track=direct, and --track=inherit. The equal sign in the latter two
cannot be replaced with whitespace; in general optional arguments need
to be attached firmly to their option.
Put "direct" consistently before "inherit", if only for the reasons
that the former is the default, explained first in the documentation,
and comes before the latter alphabetically.
Mention both modes in the short help so that readers don't have to look
them up in the full documentation. They are literal strings and thus
untranslatable. PARSE_OPT_LITERAL_ARGHELP is inferred due to the pipe
and parenthesis characters, so we don't have to provide that flag
explicitly.
Mention that -t has the same effect as --track and --track=direct.
There is no way to specify inherit mode using the short option, because
short options generally don't accept optional arguments.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git branch -h" incorrectly said "--track[=direct|inherit]",
implying that "--trackinherit" is a valid option, which has been
corrected.
* js/branch-track-inherit:
branch,checkout: fix --track usage strings
As Ævar pointed out in [1], the use of PARSE_OPT_LITERAL_ARGHELP with a
list of allowed parameters is not recommended. Both git-branch and
git-checkout were changed in d311566 (branch: add flags and config to
inherit tracking, 2021-12-20) to use this discouraged combination for
their --track flags.
Fix this by removing PARSE_OPT_LITERAL_ARGHELP, and changing the arghelp
to simply be "mode". Users may discover allowed values in the manual
pages.
[1]: https://lore.kernel.org/git/220111.86a6g3yqf9.gmgdl@evledraar.gmail.com/
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some lockfile code called free() in signal-death code path, which
has been corrected.
* ps/lockfile-cleanup-fix:
fetch: fix deadlock when cleaning up lockfiles in async signals
"git stash apply" forgot to attempt restoring untracked files when
it failed to restore changes to tracked ones.
* en/stash-df-fix:
stash: do not return before restoring untracked files
Similar message templates have been consolidated so that
translators need to work on fewer number of messages.
* ja/i18n-similar-messages:
i18n: turn even more messages into "cannot be used together" ones
i18n: ref-filter: factorize "%(foo) atom used without %(bar) atom"
i18n: factorize "--foo outside a repository"
i18n: refactor "unrecognized %(foo) argument" strings
i18n: factorize "no directory given for --foo"
i18n: factorize "--foo requires --bar" and the like
i18n: tag.c factorize i18n strings
i18n: standardize "cannot open" and "cannot read"
i18n: turn "options are incompatible" into "cannot be used together"
i18n: refactor "%s, %s and %s are mutually exclusive"
i18n: refactor "foo and bar are mutually exclusive"
"git -c branch.autosetupmerge=inherit branch new old" makes "new"
to have the same upstream as the "old" branch, instead of marking
"old" itself as its upstream.
* js/branch-track-inherit:
config: require lowercase for branch.*.autosetupmerge
branch: add flags and config to inherit tracking
branch: accept multiple upstream branches for tracking
Code clean-up to hide vreportf() from public API.
* ab/usage-die-message:
config API: use get_error_routine(), not vreportf()
usage.c + gc: add and use a die_message_errno()
gc: return from cmd_gc(), don't call exit()
usage.c API users: use die_message() for error() + exit 128
usage.c API users: use die_message() for "fatal :" + exit 128
usage.c: add a die_message() routine
Code refactoring in the reflog part of refs API.
* ab/reflog-prep:
reflog + refs-backend: move "verbose" out of the backend
refs files-backend: assume cb->newlog if !EXPIRE_REFLOGS_DRY_RUN
reflog: reduce scope of "struct rev_info"
reflog expire: don't use lookup_commit_reference_gently()
reflog expire: refactor & use "tip_commit" only for UE_NORMAL
reflog expire: use "switch" over enum values
reflog: change one->many worktree->refnames to use a string_list
reflog expire: narrow scope of "cb" in cmd_reflog_expire()
reflog delete: narrow scope of "cmd" passed to count_reflog_ent()
"git stash" by default triggers its "push" action, but its
implementation also made "git stash -h" to show short help only for
"git stash push", which has been corrected.
* ab/do-not-limit-stash-help-to-push:
stash: don't show "git stash push" usage on bad "git stash" usage
"git fetch" and "git pull" are now declared sparse-index clean.
Also "git ls-files" learns the "--sparse" option to help debugging.
* ds/fetch-pull-with-sparse-index:
test-read-cache: remove --table, --expand options
t1091/t3705: remove 'test-tool read-cache --table'
t1092: replace 'read-cache --table' with 'ls-files --sparse'
ls-files: add --sparse option
fetch/pull: use the sparse index
Use of certain "git rev-list" options with "git fast-export"
created nonsense results (the worst two of which being "--reverse"
and "--invert-grep --grep=<foo>"). The use of "--first-parent" is
made to behave a bit more sensible than before.
* ws/fast-export-with-revision-options:
fast-export: fix surprising behavior with --first-parent
Certain sparse-checkout patterns that are valid in non-cone mode
led to segfault in cone mode, which has been corrected.
* ds/sparse-checkout-malformed-pattern-fix:
sparse-checkout: refuse to add to bad patterns
sparse-checkout: fix OOM error with mixed patterns
sparse-checkout: fix segfault on malformed patterns
When fetching packfiles, we write a bunch of lockfiles for the packfiles
we're writing into the repository. In order to not leave behind any
cruft in case we exit or receive a signal, we register both an exit
handler as well as signal handlers for common signals like SIGINT. These
handlers will then unlink the locks and free the data structure tracking
them. We have observed a deadlock in this logic though:
(gdb) bt
#0 __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:95
#1 0x00007f4932bea2cd in _int_free (av=0x7f4932f2eb20 <main_arena>, p=0x3e3e4200, have_lock=0) at malloc.c:3969
#2 0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
#3 0x0000000000662ab1 in string_list_clear ()
#4 0x000000000044f5bc in unlock_pack_on_signal ()
#5 <signal handler called>
#6 _int_free (av=0x7f4932f2eb20 <main_arena>, p=<optimized out>, have_lock=0) at malloc.c:4024
#7 0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
#8 0x000000000065afd5 in strbuf_release ()
#9 0x000000000066ddb9 in delete_tempfile ()
#10 0x0000000000610d0b in files_transaction_cleanup.isra ()
#11 0x0000000000611718 in files_transaction_abort ()
#12 0x000000000060d2ef in ref_transaction_abort ()
#13 0x000000000060d441 in ref_transaction_prepare ()
#14 0x000000000060e0b5 in ref_transaction_commit ()
#15 0x00000000004511c2 in fetch_and_consume_refs ()
#16 0x000000000045279a in cmd_fetch ()
#17 0x0000000000407c48 in handle_builtin ()
#18 0x0000000000408df2 in cmd_main ()
#19 0x00000000004078b5 in main ()
The process was killed with a signal, which caused the signal handler to
kick in and try free the data structures after we have unlinked the
locks. It then deadlocks while calling free(3P).
The root cause of this is that it is not allowed to call certain
functions in async-signal handlers, as specified by signal-safety(7).
Next to most I/O functions, this list of disallowed functions also
includes memory-handling functions like malloc(3P) and free(3P) because
they may not be reentrant. As a result, if we execute such functions in
the signal handler, then they may operate on inconistent state and fail
in unexpected ways.
Fix this bug by not calling non-async-signal-safe functions when running
in the signal handler. We're about to re-raise the signal anyway and
will thus exit, so it's not much of a problem to keep the string list of
lockfiles untouched. Note that it's fine though to call unlink(2), so
we'll still clean up the lockfiles correctly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The default merge message prepared by "git merge" records the name
of the current branch; the name can be overridden with a new option
to allow users to pretend a merge is made on a different branch.
* jc/merge-detached-head-name:
merge: allow to pretend a merge is made into a different branch
"git am" learns "--empty=(stop|drop|keep)" option to tweak what is
done to a piece of e-mail without a patch in it.
* xw/am-empty:
am: support --allow-empty to record specific empty patches
am: support --empty=<option> to handle empty patches
doc: git-format-patch: describe the option --always
Many git commands that deal with working tree files try to remove a
directory that becomes empty (i.e. "git switch" from a branch that
has the directory to another branch that does not would attempt
remove all files in the directory and the directory itself). This
drops users into an unfamiliar situation if the command was run in
a subdirectory that becomes subject to removal due to the command.
The commands have been taught to keep an empty directory if it is
the directory they were started in to avoid surprising users.
* en/keep-cwd:
t2501: simplify the tests since we can now assume desired behavior
dir: new flag to remove_dir_recurse() to spare the original_cwd
dir: avoid incidentally removing the original_cwd in remove_path()
stash: do not attempt to remove startup_info->original_cwd
rebase: do not attempt to remove startup_info->original_cwd
clean: do not attempt to remove startup_info->original_cwd
symlinks: do not include startup_info->original_cwd in dir removal
unpack-trees: add special cwd handling
unpack-trees: refuse to remove startup_info->original_cwd
setup: introduce startup_info->original_cwd
t2501: add various tests for removing the current working directory
Even if some of these messages are not subject to gettext i18n, this
helps bring a single style of message for a given error type.
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
They are all replaced by "the option '%s' requires '%s'", which is a
new string but replaces 17 previous unique strings.
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use placeholders for constant tokens. The strings are turned into
"cannot be used together"
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use static strings for constant parts of the sentences. They are all
turned into "cannot be used together".
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In commit bee8691f19 ("stash: restore untracked files AFTER restoring
tracked files", 2021-09-10), we correctly identified that we should
restore changes to tracked files before attempting to restore untracked
files, and accordingly moved the code for restoring untracked files a
few lines down in do_apply_stash(). Unfortunately, the intervening
lines had some early return statements meaning that we suddenly stopped
restoring untracked files in some cases.
Even before the previous commit, there was another possible issue with
the current code -- a post-stash-apply 'git status' that was intended
to be run after restoring the stash was skipped when we hit a conflict
(or other error condition), which seems slightly inconsistent.
Fix both issues by saving the return status, and letting other
functionality run before returning.
Reported-by: AJ Henderson
Test-case-by: Randall S. Becker <randall.becker@nexbridge.ca>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "init" and "set" subcommands in "git sparse-checkout" have been
unified for a better user experience and performance.
* en/sparse-checkout-set:
sparse-checkout: remove stray trailing space
clone: avoid using deprecated `sparse-checkout init`
Documentation: clarify/correct a few sparsity related statements
git-sparse-checkout.txt: update to document init/set/reapply changes
sparse-checkout: enable reapply to take --[no-]{cone,sparse-index}
sparse-checkout: enable `set` to initialize sparse-checkout mode
sparse-checkout: split out code for tweaking settings config
sparse-checkout: disallow --no-stdin as an argument to set
sparse-checkout: add sanity-checks on initial sparsity state
sparse-checkout: break apart functions for sparse_checkout_(set|add)
sparse-checkout: pass use_stdin as a parameter instead of as a global
New interface into the tmp-objdir API to help in-core use of the
quarantine feature.
* ns/tmp-objdir:
tmp-objdir: disable ref updates when replacing the primary odb
tmp-objdir: new API for creating temporary writable databases
"git format-patch" uses a single rev_info instance and then exits.
Mark the structure with UNLEAK() macro to squelch leak sanitizer.
* jc/unleak-log:
format-patch: mark rev_info with UNLEAK
