Commit Graph

122581 Commits

Author SHA1 Message Date
Johannes Schindelin
3ea10816ca win32: add a helper to run git.exe without a foreground window
On Windows, there are two kinds of executables, console ones and
non-console ones. Git's executables are all console ones.

When launching the former e.g. in a scheduled task, a CMD window pops
up. This is not what we want for the tasks installed via the `git
maintenance` command.

To work around this, let's introduce `headless-git.exe`, which is a
non-console program that does _not_ pop up any window. All it does is to
re-launch `git.exe`, suppressing that console window, passing through
all command-line arguments as-are.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
2021-08-07 11:56:31 +02:00
Johannes Schindelin
5de9adc130 vcxproj: handle GUI programs, too
So far, we only built Console programs, but we are about to introduce a
program that targets the Windows subsystem (i.e. it is a so-called "GUI"
program).

Let's handle this preemptively in the script that generates the Visual
Studio files.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:31 +02:00
Johannes Schindelin
55be15504b vcxproj: ignore -fno-stack-protector and -fno-common
An upcoming commit will introduce those compile options; MSVC does not
understand them, so let's suppress them when generating the Visual
Studio project files.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:31 +02:00
Johannes Schindelin
4397830a3d vcxproj: handle resource files, too
On Windows, we also compile a "resource" file, which is similar to
source code, but contains metadata (such as the program version).

So far, we did not compile it in `MSVC` mode, only when compiling Git
for Windows with the GNU C Compiler.

In preparation for including it also when compiling with MS Visual C,
let's teach our `vcxproj` generator to handle those sort of files, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:30 +02:00
Johannes Schindelin
cc1bef4428 buildsystems: remove duplicate clause
This seems to have been there since 259d87c354 (Add scripts to
generate projects for other buildsystems (MSVC vcproj, QMake),
2009-09-16), i.e. since the beginning of that file.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:30 +02:00
Jeff Hostetler
453a71bf6c clink.pl: move default linker options for MSVC=1 builds
Move the default `-ENTRY` and `-SUBSYSTEM` arguments for
MSVC=1 builds from `config.mak.uname` into `clink.pl`.
These args are constant for console-mode executables.

Add support to `clink.pl` for generating a Win32 GUI application
using the `-mwindows` argument (to match how GCC does it).  This
changes the `-ENTRY` and `-SUBSYSTEM` arguments accordingly.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-07 11:56:30 +02:00
Jeff Hostetler
7d67438096 clink.pl: ignore no-stack-protector arg on MSVC=1 builds
Ignore the `-fno-stack-protector` compiler argument when building
with MSVC.  This will be used in a later commit that needs to build
a Win32 GUI app.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-07 11:56:30 +02:00
Jeff Hostetler
c1aaa735c1 config.mak.uname: add git.rc to MSVC builds
Teach MSVC=1 builds to depend on the `git.rc` file so that
the resulting executables have Windows-style resources and
version number information within them.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-07 11:56:30 +02:00
Jeff Hostetler
654aa158d8 vcbuild: add support for compiling Windows resource files
Create a wrapper for the Windows Resource Compiler (RC.EXE)
for use by the MSVC=1 builds. This is similar to the CL.EXE
and LIB.EXE wrappers used for the MSVC=1 builds.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-07 11:56:30 +02:00
Jeff Hostetler
2d49f7986d Makefile: clean up .ilk files when MSVC=1
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-07 11:56:29 +02:00
Jeff Hostetler
3c5d0638c3 clink.pl: fix libexpatd.lib link error when using MSVC
When building with `make MSVC=1 DEBUG=1`, link to `libexpatd.lib`
rather than `libexpat.lib`.

It appears that the `vcpkg` package for "libexpat" has changed and now
creates `libexpatd.lib` for debug mode builds.  Previously, both debug
and release builds created a ".lib" with the same basename.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-07 11:56:29 +02:00
Johannes Schindelin
5175ee3888 Merge branch 'dscho-avoid-d-f-conflict-in-vs-master'
Merge this early to resolve merge conflicts early.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:29 +02:00
Johannes Schindelin
3b5cf82ba6 t5505/t5516: fix white-space around redirectors
The convention in Git project's shell scripts is to have white-space
_before_, but not _after_ the `>` (or `<`).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:27 +02:00
Johannes Schindelin
ad1d57c49c t5505/t5516: allow running without .git/branches/ in the templates
When we commit the template directory as part of `make vcxproj`, the
`branches/` directory is not actually commited, as it is empty.

Two tests were not prepared for that situation.

This developer tried to get rid of the support for `.git/branches/` a
long time ago, but that effort did not bear fruit, so the best we can do
is work around in these here tests.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:27 +02:00
Johannes Schindelin
47e2a82def tests: exercise the RUNTIME_PREFIX feature
Originally, we refrained from adding a regression test in 7b6c649637
(system_path(): Add prefix computation at runtime if RUNTIME_PREFIX set,
2008-08-10), and in 226c0ddd0d (exec_cmd: RUNTIME_PREFIX on some POSIX
systems, 2018-04-10).

The reason was that it was deemed too tricky to test.

Turns out that it is not tricky to test at all: we simply create a
pseudo-root, copy the `git` executable into the `git/` subdirectory of
that pseudo-root, then copy a script into the `libexec/git-core/`
directory and expect that to be picked up.

As long as the trash directory is in a location where binaries can be
executed, this works.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:26 +02:00
Johannes Schindelin
9e2929e216 vcxproj: unclash project directories with build outputs
It already caused problems with the test suite that the directory
containing `git.vcxproj` is called the same as the Git executable
without its file extension: `./git` is ambiguous, it could refer both to
the directory `git/` as well as to `git.exe`.

Now there is one more problem: when our GitHub workflow runs on the
`vs/master` branch, it fails in all but the Windows builds, as they want
to write the file `git` but there is already a directory in the way.

Let's just go ahead and append `.proj` to all of those directories, e.g.
`git.proj/` instead of `git/`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:26 +02:00
Johannes Schindelin
6e83c5a688 mingw: ignore HOMEDRIVE/HOMEPATH if it points to Windows' system directory
Internally, Git expects the environment variable `HOME` to be set, and
to point to the current user's home directory.

This environment variable is not set by default on Windows, and
therefore Git tries its best to construct one if it finds `HOME` unset.

There are actually two different approaches Git tries: first, it looks
at `HOMEDRIVE`/`HOMEPATH` because this is widely used in corporate
environments with roaming profiles, and a user generally wants their
global Git settings to be in a roaming profile.

Only when `HOMEDRIVE`/`HOMEPATH` is either unset or does not point to a
valid location, Git will fall back to using `USERPROFILE` instead.

However, starting with Windows Vista, for secondary logons and services,
the environment variables `HOMEDRIVE`/`HOMEPATH` point to Windows'
system directory (usually `C:\Windows\system32`).

That is undesirable, and that location is usually write-protected anyway.

So let's verify that the `HOMEDRIVE`/`HOMEPATH` combo does not point to
Windows' system directory before using it, falling back to `USERPROFILE`
if it does.

This fixes git-for-windows#2709

Initial-Path-by: Ivan Pozdeev <vano@mail.mipt.ru>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:26 +02:00
Johannes Schindelin
be7e67ff7a mingw: allow git.exe to be used instead of the "Git wrapper"
Git for Windows wants to add `git.exe` to the users' `PATH`, without
cluttering the latter with unnecessary executables such as `wish.exe`.
To that end, it invented the concept of its "Git wrapper", i.e. a tiny
executable located in `C:\Program Files\Git\cmd\git.exe` (originally a
CMD script) whose sole purpose is to set up a couple of environment
variables and then spawn the _actual_ `git.exe` (which nowadays lives in
`C:\Program Files\Git\mingw64\bin\git.exe` for 64-bit, and the obvious
equivalent for 32-bit installations).

Currently, the following environment variables are set unless already
initialized:

- `MSYSTEM`, to make sure that the MSYS2 Bash and the MSYS2 Perl
  interpreter behave as expected, and

- `PLINK_PROTOCOL`, to force PuTTY's `plink.exe` to use the SSH
  protocol instead of Telnet,

- `PATH`, to make sure that the `bin` folder in the user's home
  directory, as well as the `/mingw64/bin` and the `/usr/bin`
  directories are included. The trick here is that the `/mingw64/bin/`
  and `/usr/bin/` directories are relative to the top-level installation
  directory of Git for Windows (which the included Bash interprets as
  `/`, i.e. as the MSYS pseudo root directory).

Using the absence of `MSYSTEM` as a tell-tale, we can detect in
`git.exe` whether these environment variables have been initialized
properly. Therefore we can call `C:\Program Files\Git\mingw64\bin\git`
in-place after this change, without having to call Git through the Git
wrapper.

Obviously, above-mentioned directories must be _prepended_ to the `PATH`
variable, otherwise we risk picking up executables from unrelated Git
installations. We do that by constructing the new `PATH` value from
scratch, appending `$HOME/bin` (if `HOME` is set), then the MSYS2 system
directories, and then appending the original `PATH`.

Side note: this modification of the `PATH` variable is independent of
the modification necessary to reach the executables and scripts in
`/mingw64/libexec/git-core/`, i.e. the `GIT_EXEC_PATH`. That
modification is still performed by Git, elsewhere, long after making the
changes described above.

While we _still_ cannot simply hard-link `mingw64\bin\git.exe` to `cmd`
(because the former depends on a couple of `.dll` files that are only in
`mingw64\bin`, i.e. calling `...\cmd\git.exe` would fail to load due to
missing dependencies), at least we can now avoid that extra process of
running the Git wrapper (which then has to wait for the spawned
`git.exe` to finish) by calling `...\mingw64\bin\git.exe` directly, via
its absolute path.

Testing this is in Git's test suite tricky: we set up a "new" MSYS
pseudo-root and copy the `git.exe` file into the appropriate location,
then verify that `MSYSTEM` is set properly, and also that the `PATH` is
modified so that scripts can be found in `$HOME/bin`, `/mingw64/bin/`
and `/usr/bin/`.

This addresses https://github.com/git-for-windows/git/issues/2283

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:25 +02:00
Johannes Schindelin
7f588bc13c mingw: ensure valid CTYPE
A change between versions 2.4.1 and 2.6.0 of the MSYS2 runtime modified
how Cygwin's runtime (and hence Git for Windows' MSYS2 runtime
derivative) handles locales: d16a56306d (Consolidate wctomb/mbtowc calls
for POSIX-1.2008, 2016-07-20).

An unintended side-effect is that "cold-calling" into the POSIX
emulation will start with a locale based on the current code page,
something that Git for Windows is very ill-prepared for, as it expects
to be able to pass a command-line containing non-ASCII characters to the
shell without having those characters munged.

One symptom of this behavior: when `git clone` or `git fetch` shell out
to call `git-upload-pack` with a path that contains non-ASCII
characters, the shell tried to interpret the entire command-line
(including command-line parameters) as executable path, which obviously
must fail.

This fixes https://github.com/git-for-windows/git/issues/1036

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-07 11:56:25 +02:00
Johannes Schindelin
ba452fa475 Start the merging-rebase to v2.33.0-rc1
This commit starts the rebase of ba2c6c3d88 to ca63a8f183b
2021-08-07 11:52:08 +02:00
Junio C Hamano
2d755dfac9 Git 2.33-rc1
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-06 12:53:06 -07:00
Junio C Hamano
aa7d2fe355 Merge branch 'cb/t7508-regexp-fix'
* cb/t7508-regexp-fix:
  t7508: avoid non POSIX BRE
2021-08-06 12:52:22 -07:00
Junio C Hamano
55194925e6 Merge branch 'ab/pickaxe-pcre2'
* ab/pickaxe-pcre2:
  diff: --pickaxe-all typofix
2021-08-06 12:52:15 -07:00
Junio C Hamano
c87977a0c5 Merge branch 'fc/disable-checkwinsize'
* fc/disable-checkwinsize:
  test: fix for COLUMNS and bash 5
2021-08-06 12:50:26 -07:00
Felipe Contreras
390b44eb2b test: fix for COLUMNS and bash 5
Since c49a177bec (test-lib.sh: set COLUMNS=80 for --verbose
repeatability, 2021-06-29) multiple tests have been failing when using
bash 5 because checkwinsize is enabled by default, therefore COLUMNS is
reset using TIOCGWINSZ even for non-interactive shells.

It's debatable whether or not bash should even be doing that, but for
now we can avoid this undesirable behavior by disabling this option.

Reported-by: Fabian Stelzer <fabian.stelzer@campoint.net>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
[jc: with SZEDER Gábor's suggestion to do this before setting COLUMNS]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-06 09:59:55 -07:00
Johannes Schindelin
5179b219d6 Merge pull request #3350 from dscho/trial-gfw-2.33.0.rc0-fsmonitor-pre-v4
Replace FSMonitor v2 with v4
2021-08-06 00:02:49 +02:00
Johannes Schindelin
56a0141587 fixup! mingw: support long paths
Let's re-apply the long-paths part of FSMonitor, after v4 was merged.

We also need to handle a new instance in `fsm-settings-win32.c` that
wasn't there in v2.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-05 22:41:45 +02:00
Jeff Hostetler
bcf4d40110 Merge feature.experimental markups for GFW preview 2021-08-05 21:26:21 +02:00
Johannes Schindelin
8a9b342c87 Enable the built-in FSMonitor as an experimental feature
If `feature.experimental` and `feature.manyFiles` are set, we now start
the built-in FSMonitor by default.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-05 21:26:21 +02:00
Jeff Hostetler
bc523846cd Merge branch 'builtin-fsmonitor' (preview of V4)
Left side is alternate version of v2.33.0-rc0.windows.1 with
the previous V2 version of FSMonitor removed.
2021-08-05 21:26:20 +02:00
Johannes Schindelin
e78851a724 fsmonitor: mark the built-in FSMonitor as experimental
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-05 21:26:20 +02:00
Johannes Schindelin
a0cc2340e5 fixup! Merge pull request #3234 from dscho/fsmonitor-v2
In preparation for taking FSMonitor v4, let's revert the merge of v2.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-05 21:23:51 +02:00
Johannes Schindelin
60b34f7570 fixup! mingw: support long paths
In preparation for merging FSMonitor v4, let's revert the FSMonitor part
of this patch.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-05 21:22:20 +02:00
Johannes Schindelin
d9811c094d fixup! Merge pull request #3236 from dscho/no-fsmonitor-in-bare-repos
In preparation for updating to FSMonitor v4, let's revert this.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-08-05 21:10:53 +02:00
Jeff Hostetler
12625c032a fsmonitor-settings: remote repos on Windows are incompatible with FSMonitor
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>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
2c799a2bfa fsmonitor-settings: remote repos on MacOS are incompatible with FSMonitor
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>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
d78e5132ec fsmonitor-settings: stub in platform-specific incompatibility checking on MacOS
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
cc72760a65 fsmonitor--daemon: background daemon must free the console on windows
Teach "git fsmonitor--daemon run" to call FreeConsole() when started
in the background by "git fsmonitor--daemon start" on Windows.

The background process was holding a handle to the inherited Win32
console despite being passed stdin/out/err set to /dev/null.  This
caused command prompts and powershell terminal windows to hang in
"exit" waiting for the last console handle to be released.

(This problem was not seen in git-bash type terminal windows because
they don't have a Win32 console attached to them.)

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
d2ed07d07c fsmonitor-settings: virtual repos are incompatible with FSMonitor
Virtual repos, such as GVFS (aka VFS for Git), are incompatible
with FSMonitor.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
ff00eee55f fsmonitor-settings: stub in platform-specific incompatibility checking
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>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
8956648b5d ipc-win32: add trace2 debugging
Create "ipc-debug" category events to log unexpected errors
when creating Simple-IPC connections.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
e024c753c9 t/helper/fsmonitor-client: create stress test
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>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
e1055f3444 t7527: test builtin FSMonitor watching repos with unicode paths
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>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
67a44fb0ed t7527: test FS event reporing on MacOS WRT case and Unicode
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>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
4005824c90 fsmonitor: handle shortname for .git
On Windows, teach FSMonitor to recognize the shortname of ".git"
as an alias for ".git".

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 used by the other process.  (Shortnames do seem to
be case normalized, however.)

NEEDSWORK: This only addresses the case of removing or renaming
the ".git" directory using the shortname alias, so that the daemon
properly shuts down.  I'm leaving it a task for later to handle
the general case of shortnames and report them to the fsmonitor
client process.  This would include tracked and untracked paths
that just happen to have a shortname alias.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-05 12:14:29 -04:00
Jeff Hostetler
7adc66d9d3 t7527: test status with untracked-cache and fsmonitor--daemon
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>
2021-08-05 12:14:28 -04:00
Jeff Hostetler
a7088d5ffb fsmonitor: force update index after large responses
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>
2021-08-05 12:14:28 -04:00
Jeff Hostetler
1ec372a789 fsmonitor: enhance existing comments
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2021-08-05 12:14:28 -04:00
Jeff Hostetler
56056fc1f1 fsmonitor--daemon: use a cookie file to sync with file system
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>
2021-08-05 12:14:28 -04:00
Jeff Hostetler
87bf95d6e2 fsmonitor--daemon: periodically truncate list of modified files
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>
2021-08-05 12:14:28 -04:00