Create t0052-simple-ipc.sh with unit tests for the "simple-ipc" mechanism.
Create t/helper/test-simple-ipc test tool to exercise the "simple-ipc"
functions.
When the tool is invoked with "run-daemon", it runs a server to listen
for "simple-ipc" connections on a test socket or named pipe and
responds to a set of commands to exercise/stress the communication
setup.
When the tool is invoked with "start-daemon", it spawns a "run-daemon"
command in the background and waits for the server to become ready
before exiting. (This helps make unit tests in t0052 more predictable
and avoids the need for arbitrary sleeps in the test script.)
The tool also has a series of client "send" commands to send commands
and data to a server instance.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Create Unix domain socket based implementation of "simple-ipc".
A set of `ipc_client` routines implement a client library to connect
to an `ipc_server` over a Unix domain socket, send a simple request,
and receive a single response. Clients use blocking IO on the socket.
A set of `ipc_server` routines implement a thread pool to listen for
and concurrently service client connections.
The server creates a new Unix domain socket at a known location. If a
socket already exists with that name, the server tries to determine if
another server is already listening on the socket or if the socket is
dead. If socket is busy, the server exits with an error rather than
stealing the socket. If the socket is dead, the server creates a new
one and starts up.
If while running, the server detects that its socket has been stolen
by another server, it automatically exits.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Create a wrapper class for `unix_stream_listen()` that uses a ".lock"
lockfile to create the unix domain socket in a race-free manner.
Unix domain sockets have a fundamental problem on Unix systems because
they persist in the filesystem until they are deleted. This is
independent of whether a server is actually listening for connections.
Well-behaved servers are expected to delete the socket when they
shutdown. A new server cannot easily tell if a found socket is
attached to an active server or is leftover cruft from a dead server.
The traditional solution used by `unix_stream_listen()` is to force
delete the socket pathname and then create a new socket. This solves
the latter (cruft) problem, but in the case of the former, it orphans
the existing server (by stealing the pathname associated with the
socket it is listening on).
We cannot directly use a .lock lockfile to create the socket because
the socket is created by `bind(2)` rather than the `open(2)` mechanism
used by `tempfile.c`.
As an alternative, we hold a plain lockfile ("<path>.lock") as a
mutual exclusion device. Under the lock, we test if an existing
socket ("<path>") is has an active server. If not, we create a new
socket and begin listening. Then we use "rollback" to delete the
lockfile in all cases.
This wrapper code conceptually exists at a higher-level than the core
unix_stream_connect() and unix_stream_listen() routines that it
consumes. It is isolated in a wrapper class for clarity.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Calls to `chdir()` are dangerous in a multi-threaded context. If
`unix_stream_listen()` or `unix_stream_connect()` is given a socket
pathname that is too long to fit in a `sockaddr_un` structure, it will
`chdir()` to the parent directory of the requested socket pathname,
create the socket using a relative pathname, and then `chdir()` back.
This is not thread-safe.
Teach `unix_sockaddr_init()` to not allow calls to `chdir()` when this
flag is set.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Update `unix_stream_listen()` to take an options structure to override
default behaviors. This commit includes the size of the `listen()` backlog.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
The static helper function `unix_stream_socket()` calls `die()`. This
is not appropriate for all callers. Eliminate the wrapper function
and make the callers propagate the error.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Brief design documentation for new IPC mechanism allowing
foreground Git client to talk with an existing daemon process
at a known location using a named pipe or unix domain socket.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Update the calling sequence of `read_packetized_to_strbuf()` to take
an options argument and not assume a fixed set of options. Update the
only existing caller accordingly to explicitly pass the
formerly-assumed flags.
The `read_packetized_to_strbuf()` function calls `packet_read()` with
a fixed set of assumed options (`PACKET_READ_GENTLE_ON_EOF`). This
assumption has been fine for the single existing caller
`apply_multi_file_filter()` in `convert.c`.
In a later commit we would like to add other callers to
`read_packetized_to_strbuf()` that need a different set of options.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Introduce PACKET_READ_GENTLE_ON_READ_ERROR option to help libify the
packet readers.
So far, the (possibly indirect) callers of `get_packet_data()` can ask
that function to return an error instead of `die()`ing upon end-of-file.
However, random read errors will still cause the process to die.
So let's introduce an explicit option to tell the packet reader
machinery to please be nice and only return an error on read errors.
This change prepares pkt-line for use by long-running daemon processes.
Such processes should be able to serve multiple concurrent clients and
and survive random IO errors. If there is an error on one connection,
a daemon should be able to drop that connection and continue serving
existing and future connections.
This ability will be used by a Git-aware "Builtin FSMonitor" feature
in a later patch series.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Remove the `packet_flush_gently()` call in `write_packetized_from_buf() and
`write_packetized_from_fd()` and require the caller to call it if desired.
Rename both functions to `write_packetized_from_*_no_flush()` to prevent
later merge accidents.
`write_packetized_from_buf()` currently only has one caller:
`apply_multi_file_filter()` in `convert.c`. It always wants a flush packet
to be written after writing the payload.
However, we are about to introduce a caller that wants to write many
packets before a final flush packet, so let's make the caller responsible
for emitting the flush packet.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Teach `packet_write_gently()` to write the pkt-line header and the actual
buffer in 2 separate calls to `write_in_full()` and avoid the need for a
static buffer, thread-safe scratch space, or an excessively large stack
buffer.
Change `write_packetized_from_fd()` to allocate a temporary buffer rather
than using a static buffer to avoid similar issues here.
These changes are intended to make it easier to use pkt-line routines in
a multi-threaded context with multiple concurrent writers writing to
different streams.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Disable the recent mergetool's hideresolved feature by default for
backward compatibility and safety.
* jn/mergetool-hideresolved-is-optional:
doc: describe mergetool configuration in git-mergetool(1)
mergetool: do not enable hideResolved by default
In particular, this describes mergetool.hideResolved, which can help
users discover this setting (either because it may be useful to them
or in order to understand mergetool's behavior if they have forgotten
setting it in the past).
Tested by running
make -C Documentation git-mergetool.1
man Documentation/git-mergetool.1
and reading through the page.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When 98ea309b3f (mergetool: add hideResolved configuration,
2021-02-09) introduced the mergetool.hideResolved setting to reduce
the clutter in viewing non-conflicted sections of files in a
mergetool, it enabled it by default, explaining:
No adverse effects were noted in a small survey of popular mergetools[1]
so this behavior defaults to `true`.
In practice, alas, adverse effects do appear. A few issues:
1. No indication is shown in the UI that the base, local, and remote
versions shown have been modified by additional resolution. This
is inherent in the design: the idea of mergetool.hideResolved is to
convince a mergetool that expects pristine local, base, and remote
files to show partially resolved verisons of those files instead;
there is no additional source of information accessible to the
mergetool to see where the resolution has happened.
(By contrast, a mergetool generating the partial resolution from
conflict markers for itself would be able to hilight the resolved
sections with a different color.)
A user accustomed to seeing the files without partial resolution
gets no indication that this behavior has changed when they upgrade
Git.
2. If the computed merge did not line up the files correctly (for
example due to repeated sections in the file), the partially
resolved files can be misleading and do not have enough information
to reconstruct what happened and compute the correct merge result.
3. Resolving a conflict can involve information beyond the textual
conflict. For example, if the local and remote versions added
overlapping functionality in different ways, seeing the full
unresolved versions of each alongside the base gives information
about each side's intent that makes it possible to come up with a
resolution that combines those two intents. By contrast, when
starting with partially resolved versions of those files, one can
produce a subtly wrong resolution that includes redundant extra
code added by one side that is not needed in the approach taken
on the other.
All that said, a user wanting to focus on textual conflicts with
reduced clutter can still benefit from mergetool.hideResolved=true as
a way to deemphasize sections of the code that resolve cleanly without
requiring any changes to the invoked mergetool. The caveats described
above are reduced when the user has explicitly turned this on, because
then the user is aware of them.
Flip the default to 'false'.
Reported-by: Dana Dahlstrom <dahlstrom@google.com>
Helped-by: Seth House <seth@eseth.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git for Windows's vs-build job supports both Windows x64 and arm64.
This commit re-enables that support after changes were done to the
gitgitgadget repo.
It turned out that our workaround doesn't work if the
git-credential-manager-core wrapper is put into the /arm64/bin folder,
but is does work when putting it into the /arm64/libexec folder.
This PR moves the git-credential-manager-core wrapper to /arm64/libexec.
Signed-off-by: Dennis Ameling <dennis@dennisameling.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This topic branch re-adds the deprecated --stdin/-z options to `git
reset`. Those patches were overridden by a different set of options in
the upstream Git project before we could propose `--stdin`.
We offered this in MinGit to applications that wanted a safer way to
pass lots of pathspecs to Git, and these applications will need to be
adjusted.
Instead of `--stdin`, `--pathspec-from-file=-` should be used, and
instead of `-z`, `--pathspec-file-nul`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This branch allows third-party tools to call `git status
--no-lock-index` to avoid lock contention with the interactive Git usage
of the actual human user.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
These are Git for Windows' Git GUI and gitk patches. We will have to
decide at some point what to do about them, but that's a little lower
priority (as Git GUI seems to be unmaintained for the time being, and
the gitk maintainer keeps a very low profile on the Git mailing list,
too).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is the recommended way on GitHub to describe policies revolving around
security issues and about supported versions.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Rather than using private IFTTT Applets that send mails to this
maintainer whenever a new version of a Git for Windows component was
released, let's use the power of GitHub workflows to make this process
publicly visible.
This workflow monitors the Atom/RSS feeds, and opens a ticket whenever a
new version was released.
Note: Bash sometimes releases multiple patched versions within a few
minutes of each other (i.e. 5.1p1 through 5.1p4, 5.0p15 and 5.0p16). The
MSYS2 runtime also has a similar system. We can address those patches as
a group, so we shouldn't get multiple issues about them.
Note further: We're not acting on newlib releases, OpenSSL alphas, Perl
release candidates or non-stable Perl releases. There's no need to open
issues about them.
Co-authored-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Git documentation refers to $HOME and $XDG_CONFIG_HOME often, but does not specify how or where these values come from on Windows where neither is set by default. The new documentation reflects the behavior of setup_windows_environment() in compat/mingw.c.
Signed-off-by: Alejandro Barreto <alejandro.barreto@ni.com>
Git for Windows accepts pull requests; Core Git does not. Therefore we
need to adjust the template (because it only matches core Git's
project management style, not ours).
Also: direct Git for Windows enhancements to their contributions page,
space out the text for easy reading, and clarify that the mailing list
is plain text, not HTML.
Signed-off-by: Philip Oakley <philipoakley@iee.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
