Update wchar_t buffers to use MAX_LONG_PATH instead of MAX_PATH in
the Win32 backend source files.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
If `feature.experimental` and `feature.manyFiles` are set and the user
has not explicitly turned off the builtin FSMonitor, we now start
the built-in FSMonitor by default.
Only forcing it when UNSET matches the behavior of UPDATE_DEFAULT_BOOL()
used for other repo settings.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach Git to perform binary search over the cache-entries for a directory
notification and then linearly scan forward to find the immediate children.
Previously, when the FSMonitor reported a modified directory Git would
perform a linear search on the entire cache-entry array for all
entries matching that directory prefix and invalidate them. Since the
cache-entry array is already sorted, we can use a binary search to
find the first matching entry and then only linearly walk forward and
invalidate entries until the prefix changes.
Also, the original code would invalidate anything having the same
directory prefix. Since a directory event should only be received for
items that are immediately within the directory (and not within
sub-directories of it), only invalidate those entries and not the
whole subtree.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach the listener thread to shutdown the daemon if the spelling of the
worktree root directory changes.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Create framework in Win32 version of the "health" thread to
periodically inspect the system and shutdown if warranted.
This version just include the setup for the timeout in
WaitForMultipleObjects() and calls (currently empty) table
of functions.
A later commit will add functions to the table to actually
inspect the system.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
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>
Ignore FSEvents resulting from `xattr` changes. Git does not care about
xattr's or changes to xattr's, so don't waste time collecting these
events in the daemon nor transmitting them to clients.
Various security tools add xattrs to files and/or directories, such as
to mark them as having been downloaded. We should ignore these events
since it doesn't affect the content of the file/directory or the normal
meta-data that Git cares about.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Initialize `o->result.fsmonitor_has_run_once` based upon value
in `o->src_index->fsmonitor_has_run_once` to prevent a second
fsmonitor query during the tree traversal and possibly getting
a skewed view of the working directory.
The checkout code has already talked to the fsmonitor and the
traversal is updating the index as it traverses, so there is
no need to query the fsmonitor.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach Git to detect remote working directories on Windows and mark them as
incompatible with FSMonitor.
With this `git fsmonitor--daemon run` will error out with a message like it
does for bare repos.
Client commands, such as `git status`, will not attempt to start the daemon.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach Git to detect remote working directories on MacOS and mark them as
incompatible with FSMonitor.
With this, `git fsmonitor--daemon run` will error out with a message
like it does for bare repos.
Client commands, like `git status`, will not attempt to start the daemon.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
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>
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>
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>
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>
