Extend generic incompatibility checkout with platform-specific
mechanism. Stub in Win32 version.
In the existing fsmonitor-settings code we have a way to mark
types of repos as incompatible with fsmonitor (whether via the
hook and ipc APIs). For example, we do this for bare repos,
since there are no files to watch.
Extend this exclusion mechanism for platfor-specific reasons.
This commit just creates the framework and adds a stub for Win32.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Create a stress test to hammer on the fsmonitor daemon.
Create a client-side thread pool of n threads and have
each of them make m requests as fast as they can.
NEEDSWORK: This is just the client-side thread pool and
is useful for interactive testing and experimentation.
We need to add a script test to drive this.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Create some test repos with UTF8 pathnames and verify that
the builtin FSMonitor can watch them. This test is mainly
for Windows where we need to avoid `*A()` routines.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Confirm that MacOS FS events are reported with a normalized spelling.
APFS (and/or HFS+) is case-insensitive. This means that case-independent
lookups ( [ -d .git ] and [ -d .GIT ] ) should both succeed. But that
doesn't tell us how FS events are reported if we try "rm -rf .git" versus
"rm -rf .GIT". Are the events reported using the on-disk spelling of the
pathname or in the spelling used by the command.
NEEDSWORK: I was only able to test case. It would be nice to add tests
that use different Unicode spellings/normalizations and understand the
differences between APFS and HFS+ in this area. We should confirm that
the spelling of the workdir paths that the daemon sends to clients are
always properly normalized.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach FSMonitor daemon on Windows to recognize shortname paths as
aliases of normal longname paths. FSMonitor clients, such as `git
status`, should receive the longname spelling of changed files (when
possible).
Sometimes we receive FS events using the shortname, such as when a CMD
shell runs "RENAME GIT~1 FOO" or "RMDIR GIT~1". The FS notification
arrives using whatever combination of long and shortnames were used by
the other process. (Shortnames do seem to be case normalized,
however.)
Use Windows GetLongPathNameW() to try to map the pathname spelling in
the notification event into the normalized longname spelling. (This
can fail if the file/directory is deleted, moved, or renamed, because
we are asking the FS for the mapping in response to the event and
after it has already happened, but we try.)
Special case the shortname spelling of ".git" to avoid under-reporting
these events.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Create 2x2 test matrix with the untracked-cache and fsmonitor--daemon
features and a series of edits and verify that status output is
identical.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Set the `FSMONITOR_CHANGED` bit on `istate->cache_changed` when
FSMonitor returns a very large repsonse to ensure that the index is
written to disk.
Normally, when the FSMonitor response includes a tracked file, the
index is always updated. Similarly, the index might be updated when
the response alters the untracked-cache (when enabled). However, in
cases where neither of those cause the index to be considered changed,
the FSMonitor response is wasted. Subsequent Git commands will make
requests with the same token and receive the same response.
If that response is very large, performance may suffer. It would be
more efficient to force update the index now (and the token in the
index extension) in order to reduce the size of the response received
by future commands.
This was observed on Windows after a large checkout. On Windows, the
kernel emits events for the files that are changed as they are
changed. However, it might delay events for the containing
directories until the system is more idle (or someone scans the
directory (so it seems)). The first status following a checkout would
get the list of files. The subsequent status commands would get the
list of directories as the events trickled out. But they would never
catch up because the token was not advanced because the index wasn't
updated.
This list of directories caused `wt_status_collect_untracked()` to
unnecessarily spend time actually scanning them during each command.
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>
Repeat all of the fsmonitor perf tests using `git fsmonitor--daemon` and
the "Simple IPC" interface.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Change p7519 to use `test_seq` and `xargs` rather than a `for` loop
to touch thousands of files. This takes minutes off of test runs
on Windows because of process creation overhead.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach `test-tool.exe chmtime` to ignore errors when setting the mtime
on a directory on Windows.
NEEDSWORK: The Windows version of `utime()` (aka `mingw_utime()`) does
not properly handle directories because it uses `_wopen()`. It should
be converted to using `CreateFileW()` and backup semantics at a minimum.
Since I'm already in the middle of a large patch series, I did not want
to destabilize other callers of `utime()` right now. The problem has
only been observed in the t/perf/p7519 test when the test repo contains
an empty directory on disk.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Do not copy any of the various fsmonitor--daemon files from the .git
directory of the (GIT_PREF_REPO or GIT_PERF_LARGE_REPO) source repo
into the test's trash directory.
When perf tests start, they copy the contents of the source repo into
the test's trash directory. If fsmonitor is running in the source repo,
there may be control files, such as the IPC socket and/or fsmonitor
cookie files. These should not be copied into the test repo.
Unix domain sockets cannot be copied in the manner used by the test
setup, so if present, the test setup fails.
Cookie files are harmless, but we should avoid them.
The builtin fsmonitor keeps all such control files/sockets in
.git/fsmonitor--daemon*, so it is simple to exclude them.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Add the "feature: fsmonitor--daemon" message to the output of
`git version --build-options`.
The builtin FSMonitor is only available on certain platforms and
even then only when certain Makefile flags are enabled, so print
a message in the verbose version output when it is available.
This can be used by test scripts for prereq testing. Granted, tests
could just try `git fsmonitor--daemon status` and look for a 128 exit
code or grep for a "not supported" message on stderr, but this is
rather obscure.
The main advantage is that the feature message will automatically
appear in bug reports and other support requests.
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>
Include MacOS system declarations to allow us to use FSEvent and
CoreFoundation APIs. We need GCC and clang versions because of
compiler and header file conflicts.
While it is quite possible to #include Apple's CoreServices.h when
compiling C source code with clang, trying to build it with GCC
currently fails with this error:
In file included
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/Security.framework/Headers/AuthSession.h:32,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/Security.framework/Headers/Security.h:42,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/CSIdentity.h:43,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/OSServices.framework/Headers/OSServices.h:29,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/IconsCore.h:23,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Headers/LaunchServices.h:23,
from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:45,
/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/Security.framework/Headers/Authorization.h:193:7: error: variably modified 'bytes' at file scope
193 | char bytes[kAuthorizationExternalFormLength];
| ^~~~~
The underlying reason is that GCC (rightfully) objects that an `enum`
value such as `kAuthorizationExternalFormLength` is not a constant
(because it is not, the preprocessor has no knowledge of it, only the
actual C compiler does) and can therefore not be used to define the size
of a C array.
This is a known problem and tracked in GCC's bug tracker:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93082
In the meantime, let's not block things and go the slightly ugly route
of declaring/defining the FSEvents constants, data structures and
functions that we need, so that we can avoid above-mentioned issue.
Let's do this _only_ for GCC, though, so that the CI/PR builds (which
build both with clang and with GCC) can guarantee that we _are_ using
the correct data types.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach the win32 backend to register a watch on the working tree
root directory (recursively). Also watch the <gitdir> if it is
not inside the working tree. And to collect path change notifications
into batches and publish.
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>
Update references to `core.fsmonitor` and `core.fsmonitorHookVersion` and
pointers to `Watchman` to mention the new `core.useBuiltinFSMonitor`
value.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Use simple IPC to directly communicate with the new builtin file
system monitor daemon when `core.useBuiltinFSMonitor` is set.
The `core.fsmonitor` setting has already been defined as a HOOK
pathname. Historically, this has been set to a HOOK script that will
talk with Watchman. For compatibility reasons, we do not want to
overload that definition (and cause problems if users have multiple
versions of Git installed).
Signed-off-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>
Create fsmonitor_ipc__*() client routines to spawn the built-in file
system monitor daemon and send it an IPC request using the `Simple
IPC` API.
Stub in empty fsmonitor_ipc__*() functions for unsupported platforms.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
A recent upstream topic introduced checks for certain Git commands that
prevent them from deleting the current working directory, introducing
also a regression test that ensures that commands such as `git version`
_can_ run without a current working directory.
While technically not possible on Windows via the regular Win32 API, we
do run the regression tests in an MSYS2 Bash which uses a POSIX
emulation layer (the MSYS2/Cygwin runtime) where a really evil hack
_does_ allow to delete a directory even if it is the current working
directory.
Therefore, Git needs to be prepared for a missing working directory,
even on Windows.
This issue was not noticed in upstream Git because there was no caller
that tried to discover a Git directory with a deleted current working
directory in the test suite. But in the microsoft/git fork, we do want
to run `pre-command`/`post-command` hooks for every command, even for
`git version`, which means that we make precisely such a call. The bug
is not in that `pre-command`/`post-command` feature, though, but in
`mingw_getcwd()` and needs to be addressed there.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.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
FreeBSD 13.0 headers have unconditional dependency on C11 language
features, and adding -std=gnu99 to DEVELOPER_CFLAGS would just
break the developer build.
* jc/freebsd-without-c99-only-build:
Makefile: FreeBSD cannot do C99-or-below build
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>
In "make DEVELOPER=YesPlease" builds, we try to help developers to
catch as many potential issues as they can by using -Wall and
turning compilation warnings into errors. In the same spirit, we
recently started adding -std=gnu99 to their CFLAGS, so that they can
notice when they accidentally used language features beyond C99.
It however turns out that FreeBSD 13.0 mistakenly uses C11 extension
in its system header files regardless of what __STDC_VERSION__ says,
which means that the platform (unless we tweak their system headers)
cannot be used for this purpose.
It seems that -std=gnu99 is only added conditionally even in today's
config.mak.dev, so it is fine if we dropped -std=gnu99 from there.
Which means that developers on FreeBSD cannot participate in vetting
use of features beyond C99, but there are developers on other
platforms who will, so it's not too bad.
We might want a more "fundamental" fix to make the platform capable
of taking -std=gnu99, like working around the use of unconditional
C11 extension in its system header files by supplying a set of
"replacement" definitions in our header files. We chose not to
pursue such an approach for two reasons at this point:
(1) The fix belongs to the FreeBSD project, not this project, and
such an upstream fix may happen hopefully in a not-too-distant
future.
(2) Fixing such a bug in system header files and working it around
can lead to unexpected breakages (other parts of their system
header files may not be expecting to see and do not work well
with our "replacement" definitions). This close to the final
release of this cycle, we have no time for that.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adjust build on RHEL 7 to explicitly ask C99 support and use
the fallback implementation of uncompress2 we ship.
* da/rhel7-lacks-uncompress2-and-c99:
build: centos/RHEL 7 ships with an older gcc and zlib
GCC 4.8.5 is the default system compiler on centos7/RHEL7.
This version requires -std=c99 to enable c99 support.
zlib 1.2.7 on centos7/rhel7 lacks uncompress2().
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
