GitHub Actions scheduled a brownout of Ubuntu 18.04, which canceled all
runs of the 'static-analysis' job in our CI runs. Update to 22.04 to
avoid this as the brownout later turns into a complete deprecation.
The use of 18.04 was set in d051ed77ee (.github/workflows/main.yml: run
static-analysis on bionic, 2021-02-08) due to the lack of Coccinelle
being available on 20.04 (which continues today).
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Pass the number of elements first and their size second, as expected
by xcalloc().
Patch generated with:
make SPATCH_FLAGS=--recursive-includes contrib/coccinelle/xcalloc.cocci.patch
Our default SPATCH_FLAGS ('--all-includes') doesn't catch this
transformation by default, unless used in combination with a large-ish
SPATCH_BATCH_SIZE which happens to put 'promisor-remote.c' with a file
that includes 'repository.h' directly in the same batch.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a memory leak occuring in case of pathspec copy in preload_index.
Direct leak of 8 byte(s) in 8 object(s) allocated from:
#0 0x7f0a353ead47 in __interceptor_malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/11.3.0/libasan.so.6+0xb5d47)
#1 0x55750995e840 in do_xmalloc /home/anthony/src/c/git/wrapper.c:51
#2 0x55750995e840 in xmalloc /home/anthony/src/c/git/wrapper.c:72
#3 0x55750970f824 in copy_pathspec /home/anthony/src/c/git/pathspec.c:684
#4 0x557509717278 in preload_index /home/anthony/src/c/git/preload-index.c:135
#5 0x55750975f21e in refresh_index /home/anthony/src/c/git/read-cache.c:1633
#6 0x55750915b926 in cmd_status builtin/commit.c:1547
#7 0x5575090e1680 in run_builtin /home/anthony/src/c/git/git.c:466
#8 0x5575090e1680 in handle_builtin /home/anthony/src/c/git/git.c:720
#9 0x5575090e284a in run_argv /home/anthony/src/c/git/git.c:787
#10 0x5575090e284a in cmd_main /home/anthony/src/c/git/git.c:920
#11 0x5575090dbf82 in main /home/anthony/src/c/git/common-main.c:56
#12 0x7f0a348230ab (/lib64/libc.so.6+0x290ab)
Signed-off-by: Anthony Delannoy <anthony.2lannoy@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Failures within `for` and `while` loops can go unnoticed if not detected
and signaled manually since the loop itself does not abort when a
contained command fails, nor will a failure necessarily be detected when
the loop finishes since the loop returns the exit code of the last
command it ran on the final iteration, which may not be the command
which failed. Therefore, detect and signal failures manually within
loops using the idiom `|| return 1` (or `|| exit 1` within subshells).
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This test wants to verify that `git blame` errors out when asked to
blame a file _not_ in the sparse checkout. However, the very first file
it asks to blame _is_ present in the checkout, thus `test_must_fail git
blame $file` gives an unexpected result (the "blame" succeeds). This
problem went unnoticed because the test invokes `test_must_fail git
blame $file` in loop but forgets to break out of the loop early upon
failure, thus the failure gets swallowed.
Fix the test by having it not ask to blame a file present in the sparse
checkout, and instead only blame files not present, as intended. While
at it, also add the missing `|| return 1` which allowed this bug to go
unnoticed.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The breaks in the &&-chain in this test went unnoticed because the
"magic exit code 117" &&-chain checker built into test-lib.sh only
recognizes broken &&-chains at the top-level; it does not work within
`{...}` groups, `(...)` subshells, `$(...)` substitutions, or within
bodies of compound statements, such as `if`, `for`, `while`, `case`,
etc. Furthermore, `chainlint.sed` detects broken &&-chains only in
`(...)` subshells. Thus, the &&-chain breaks in this test fall into the
blind spots of the &&-chain linters.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The entry point to the patience-diff algorithm takes two mmfile_t
structs with the original file contents, but it doesn't actually do
anything useful with them. This is similar to the case recently cleaned
up in the histogram code via f1d019071e (xdiff: drop unused mmfile
parameters from xdl_do_histogram_diff(), 2022-08-19), but there's a bit
more subtlety going on.
We pass them into the recursive patience_diff(), which in turn passes
them into fill_hashmap(), which stuffs the pointers into a struct. But
the only thing which reads the struct fields is our recursion into
patience_diff()!
So it's unlikely that something like -Wunused-parameter could find this
case: it would have to detect the circular dependency caused by the
recursion (not to mention tracing across struct field assignments).
But once found, it's easy to have the compiler confirm what's going on:
1. Drop the "file1" and "file2" fields from the hashmap struct
definition. Remove the assignments in fill_hashmap(), and
temporarily substitute NULL in the recursive call to
patience_diff(). Compiling shows that no other code touched those
fields.
2. Now fill_hashmap() will trigger -Wunused-parameter. Drop "file1"
and "file2" from its definition and callsite.
3. Now patience_diff() will trigger -Wunused-parameter. Drop them
there, too. One of the callsites is the recursion with our
NULL values, so those temporary values go away.
4. Now xdl_do_patience_diff() will trigger -Wunused-parameter. Drop
them there. And we're done.
Suggested-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the spirit of 517fe807d6 (assert NOARG/NONEG behavior of
parse-options callbacks, 2018-11-05), this asserts that our callbacks
were invoked using the right flags (since otherwise they'd segfault on
the NULL arg). Both cases are already correct here, so this is mostly
about annotating the functions, and appeasing -Wunused-parameters.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The reader code passes around a "struct reftable_reader" context
variable. But the seek function doesn't need it; the table iterator we
already get is sufficient.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function has never used its repository or cache_tree parameters
since it was introduced in 9ad2d5ea71 (sparse-index: loose integration
with cache_tree_verify(), 2021-03-30).
As that commit notes, it may eventually be extended further, and that
might require looking at more data. But we can easily add them back if
necessary (and the repository is even included in the index_state these
days already). In the mean time, dropping them makes the code shorter
and appeases -Wunused-parameter.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the 'p0006' test "read-tree br_base br_ballast", move the '-n' flag used
in 'git read-tree' ahead of its positional arguments.
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix multi-threaded 'p0004' test's use of the 'REPO_BIG_ENOUGH_FOR_MULTI'
prerequisite. Unlike normal 't/' tests, 't/perf/' tests need to have their
prerequisites declared with the '--prereq' flag.
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When action_name is used to denote a command `git %s` do not translate
since command names are never translated.
Suggested-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`error_resolve_conflict()` checks the untranslated action_name
parameter, so pass it as is.
Suggested-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Traditionally, reflog messages were never translated, in particular not
on storage.
Due to the switch of more parts of git to the sequencer, old changes in
the sequencer code may lead to recent changes in git's behaviour. E.g.:
c28cbc5ea6 ("sequencer: mark action_name() for translation", 2016-10-21)
marked several uses of `action_name()` for translation. Recently, this
lead to a partially translated reflog:
`rebase: fast-forward` is translated (e.g. in de to `Rebase: Vorspulen`)
whereas other reflog entries such as `rebase (pick):` remain
untranslated as they should be.
Change the relevant line in the sequencer so that this reflog entry
remains untranslated, as well.
Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This field has not been used since the function was introduced in
b559263216 (exclude: split pathname matching code into a separate
function, 2012-10-15), though there was a brief period where it was
erroneously used and then reverted in ed4958477b (dir: fix pattern
matching on dirs, 2021-09-24) and 5ceb663e92 (dir: fix
directory-matching bug, 2021-11-02).
It's possible we'd eventually add a flag that makes it useful here, but
there are only a handful of callers. It would be easy to add back if
necessary, and in the meantime this makes the function interface less
misleading.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function has never used its "commit" parameter since it was added
in db757e8b8d (show, log: provide a --remerge-diff capability,
2022-02-02).
This makes sense; we already have separate parameters for the parents
(which lets us redo the merge) and the oid of the result tree (which we
can then diff against the remerge result).
Let's drop the unused parameter in the name of clarity.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These are no longer used since 9df0fc3d57 (xdiff: fix a memory leak,
2022-02-16), as the caller is expected to call xdl_prepare_env() itself.
After that change the histogram code only examines the prepared
xdfenv_t, not the original buffers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If GIT_PS1_SHOWCONFLICTSTATE is set to "yes", show the word "CONFLICT"
on the command prompt when there are unresolved conflicts.
Example prompt: (main|CONFLICT)
Signed-off-by: Justin Donnelly <justinrdonnelly@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have long allowed users to run e.g.
git log --ancestry-path master..seen
which shows all commits which satisfy all three of these criteria:
* are an ancestor of seen
* are not an ancestor of master
* have master as an ancestor
This commit allows another variant:
git log --ancestry-path=$TOPIC master..seen
which shows all commits which satisfy all of these criteria:
* are an ancestor of seen
* are not an ancestor of master
* have $TOPIC in their ancestry-path
that last bullet can be defined as commits meeting any of these
criteria:
* are an ancestor of $TOPIC
* have $TOPIC as an ancestor
* are $TOPIC
This also allows multiple --ancestry-path arguments, which can be
used to find commits with any of the given topics in their ancestry
path.
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The tests in t6019 are repetitive, so create a helper that greatly
simplifies the test script.
In addition, update the common pattern that places 'git rev-list' on the
left side of a pipe, which can hide some exit codes. Send the output to
a 'raw' file that is then consumed by other tools so the Git exit code
is verified as zero. And since we're using --format anyway, switch to
`git log`, so that we get the desired format and can avoid using sed.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 66b209b86a ("merge-ort: implement CE_SKIP_WORKTREE handling with
conflicted entries", 2021-03-20) added some code for merge-ort to handle
conflicted and skip_worktree entries in general. Included in this was
an ugly hack for dealing with present-despite-skipped entries and a
testcase (t6428.2) specific to that hack, since at that time users could
accidentally get files into that state when using a sparse checkout.
However, with the merging of 82386b4496 ("Merge branch
'en/present-despite-skipped'", 2022-03-09), that class of problems was
addressed globally and in a much cleaner way. As such, the
present-despite-skipped hack in merge-ort is no longer needed and can
simply be removed.
No additional testcase is needed here; t6428.2 was written to test the
necessary functionality and is being kept. The fact that this test
continues to pass despite the code being removed shows that the extra
code is no longer necessary.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update the Scalar roadmap to reflect completion of enabling the built-in
FSMonitor in Scalar.
Note that implementation of 'scalar help' was moved to the final set of
changes to move Scalar out of 'contrib/'. This is due to a dependency on
changes to 'git help', as all changes to the main Git tree *exclusively*
implemented to support Scalar are part of that series.
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Especially on Windows, we will need to stop that daemon, just in case
that the directory needs to be removed (the daemon would otherwise hold
a handle to that directory, preventing it from being deleted).
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using the built-in FSMonitor makes many common commands quite a bit
faster. So let's teach the `scalar register` command to enable the
built-in FSMonitor and kick-start the fsmonitor--daemon process (for
convenience).
For simplicity, we only support the built-in FSMonitor (and no external
file system monitor such as e.g. Watchman).
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Matthew John Cheetham <mjcheetham@outlook.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create function 'set_scalar_config()' to contain the logic used in setting
Scalar-defined Git config settings, including how to handle reconfiguring &
overwriting existing values. This function allows future patches to set
config values in parts of 'scalar.c' other than 'set_recommended_config()'.
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rather than exiting with 'die()' when 'delete_enlistment()' encounters an
error, return an error code with the appropriate message. There's no need
for an abrupt exit with 'die()' in 'delete_enlistment()' because its only
caller ('cmd_delete()') properly cleans up allocated resources and returns
the 'delete_enlistment()' return value as its own exit code.
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a step in 'register_dir()' or 'unregister_dir()' fails, indicate which
step failed with an error message, rather than silently assigning a nonzero
return code.
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When 'scalar unregister' tries to disable maintenance and remove an
enlistment, ensure that the return value is nonzero if either operation
produces *any* nonzero return value, not just when they return a value less
than 0.
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the search for repository and enlistment root in
'setup_enlistment_directory()' more constrained to simplify behavior and
adhere to 'GIT_CEILING_DIRECTORIES'.
Previously, 'setup_enlistment_directory()' would check whether the provided
path (or current working directory) '<dir>' or its subdirectory '<dir>/src'
was a repository root. If not, the process would repeat on the parent of
'<dir>' until the repository was found or it reached the root of the
filesystem. This meant that a user could specify a path *anywhere* inside an
enlistment (including paths not in the repository contained within the
enlistment) and it would be found.
The downside to this process is that the search would not account for
'GIT_CEILING_DIRECTORIES', so the upward search could result in modifying
repository contents past 'GIT_CEILING_DIRECTORIES'. Similarly, operations
like 'scalar delete' could end up unintentionally deleting the parent of a
repo if its root was named 'src'.
To make this 'setup_enlistment_directory()' both adhere to
'GIT_CEILING_DIRECTORIES' and avoid unwanted deletions, the search for an
enlistment directory is simplified to:
- if '<dir>/src' is a repository root, '<dir>' is the enlistment root
- if '<dir>' is either the repository root or contained within a repository,
the repository root is the enlistment root
Now, only 'setup_git_directory()' (called by 'setup_enlistment_directory()')
searches upwards from the 'scalar' specified path, enforcing
'GIT_CEILING_DIRECTORIES' in the process. Additionally, 'scalar delete
<dir>/src' will not delete '<dir>' (if users would like to delete it, they
can still specify the enlistment root with 'scalar delete <dir>'). This is
true of any 'scalar' operation; users can invoke 'scalar' on the enlistment
root, but paths must otherwise be inside the repository to be valid.
To help clarify the updated behavior, new tests are added to
't9099-scalar.sh'.
Finally, this change leaves 'strbuf_parent_directory()' with only a single,
WIN32-specific caller in 'delete_enlistment()'. Rather than wrap
'strbuf_parent_directory()' in '#ifdef WIN32' to avoid the "unused function"
compiler error, move the contents of 'strbuf_parent_directory()' into
'delete_enlistment()' and remove the function.
Helped-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rev-list --disk-usage" learned to take an optional value
"human" to show the reported value in human-readable format, like
"3.40MiB".
* ll/disk-usage-humanise:
rev-list: support human-readable output for `--disk-usage`
"git rm" has become more aware of the sparse-index feature.
* sy/sparse-rm:
rm: integrate with sparse-index
rm: expand the index only when necessary
pathspec.h: move pathspec_needs_expanded_index() from reset.c to here
t1092: add tests for `git-rm`
Fixes to sparse index compatibility work for "reset" and "checkout"
commands.
* vd/sparse-reset-checkout-fixes:
unpack-trees: unpack new trees as sparse directories
cache.h: create 'index_name_pos_sparse()'
oneway_diff: handle removed sparse directories
checkout: fix nested sparse directory diff in sparse index
"git fsck" reads mode from tree objects but canonicalizes the mode
before passing it to the logic to check object sanity, which has
hid broken tree objects from the checking logic. This has been
corrected, but to help exiting projects with broken tree objects
that they cannot fix retroactively, the severity of anomalies this
code detects has been demoted to "info" for now.
* jk/fsck-tree-mode-bits-fix:
fsck: downgrade tree badFilemode to "info"
fsck: actually detect bad file modes in trees
tree-walk: add a mechanism for getting non-canonicalized modes
In commit 4057523a40 ("submodule merge: update conflict error message",
2022-08-04), a more detailed message was provided when submodules
conflict, in order to help users know how to resolve those conflicts.
There were a couple situations for which a different message would be
more appropriate, but that commit left handling those for future work.
Unfortunately, that commit would check if any submodules were of the
type that it didn't know how to explain, and, if so, would avoid
providing the more detailed explanation even for the submodules it did
know how to explain.
Change this to have the code print the helpful messages for the subset
of submodules it knows how to explain.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 4057523a40 ("submodule merge: update conflict error message",
2022-08-04) added a sub_flag variable that is used to store a value from
enum conflict_and_info_types, but initializes it with a value of -1 that
does not correspond to any of the conflict_and_info_types. The code may
never set it to a valid value and yet still use it, which can be
surprising when reading over the code at first. Initialize it instead
to the generic CONFLICT_SUBMODULE_FAILED_TO_MERGE value, which is still
distinct from the two values we need to special case.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In commit 4057523a40 ("submodule merge: update conflict error message",
2022-08-04), the new "submodule conflict suggestion" code was
translating 6 different pieces of the new message and then used
carefully crafted logic to allow stitching it back together with special
formatting. Keep the components of the message together as much as
possible, so that:
* we reduce the number of things translators have to translate
* translators have more control over the format of the output
* the code is much easier for developers to understand too
Also, reformat some comments running beyond the 80th column while at it.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our pipe_command() helper lets you both write to and read from a child
process on its stdin/stdout. It's supposed to work without deadlocks
because we use poll() to check when descriptors are ready for reading or
writing. But there's a bug: if both the data to be written and the data
to be read back exceed the pipe buffer, we'll deadlock.
The issue is that the code assumes that if you have, say, a 2MB buffer
to write and poll() tells you that the pipe descriptor is ready for
writing, that calling:
write(cmd->in, buf, 2*1024*1024);
will do a partial write, filling the pipe buffer and then returning what
it did write. And that is what it would do on a socket, but not for a
pipe. When writing to a pipe, at least on Linux, it will block waiting
for the child process to read() more. And now we have a potential
deadlock, because the child may be writing back to us, waiting for us to
read() ourselves.
An easy way to trigger this is:
git -c add.interactive.useBuiltin=true \
-c interactive.diffFilter=cat \
checkout -p HEAD~200
The diff against HEAD~200 will be big, and the filter wants to write all
of it back to us (obviously this is a dummy filter, but in the real
world something like diff-highlight would similarly stream back a big
output).
If you set add.interactive.useBuiltin to false, the problem goes away,
because now we're not using pipe_command() anymore (instead, that part
happens in perl). But this isn't a bug in the interactive code at all.
It's the underlying pipe_command() code which is broken, and has been
all along.
We presumably didn't notice because most calls only do input _or_
output, not both. And the few that do both, like gpg calls, may have
large inputs or outputs, but never both at the same time (e.g., consider
signing, which has a large payload but a small signature comes back).
The obvious fix is to put the descriptor into non-blocking mode, and
indeed, that makes the problem go away. Callers shouldn't need to
care, because they never see the descriptor (they hand us a buffer to
feed into it).
The included test fails reliably on Linux without this patch. Curiously,
it doesn't fail in our Windows CI environment, but has been reported to
do so for individual developers. It should pass in any environment after
this patch (courtesy of the compat/ layers added in the last few
commits).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When write() to a non-blocking pipe fails because the buffer is full,
POSIX says we should see EAGAIN. But our mingw_write() compat layer on
Windows actually returns ENOSPC for this case. This is probably
something we want to correct, but given that we don't plan to use
non-blocking descriptors in a lot of places, we can work around it by
just catching ENOSPC alongside EAGAIN. If we ever do fix mingw_write(),
then this patch can be reverted.
We don't actually use a non-blocking pipe yet, so this is still just
preparation.
Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If xwrite() sees an EAGAIN response, it will loop forever until the
write succeeds (or encounters a real error). This is due to ef1cf0167a
(xwrite: poll on non-blocking FDs, 2016-06-26), with the idea that we
won't be surprised by a descriptor unexpectedly set as non-blocking.
But that will make things awkward when we do want a non-blocking
descriptor, and a future patch will switch pipe_command() to using one.
In that case, looping on EAGAIN is bad, because the process on the other
end of the pipe may be waiting on us before doing another read() on the
pipe, which would mean we deadlock.
In practice we're not supposed to ever see EAGAIN here, since poll()
will have just told us the descriptor is ready for writing. But our
Windows emulation of poll() will always return "ready" for writing to a
pipe descriptor! This is due to 94f4d01932 (mingw: workaround for hangs
when sending STDIN, 2020-02-17).
Our best bet in that case is to keep handling other descriptors, as any
read() we do may allow the child command to make forward progress (i.e.,
its write() finishes, and then it read()s from its stdin, freeing up
space in the pipe buffer). This means we might busy-loop between poll()
and write() on Windows if the child command is slow to read our input,
but it's much better than the alternative of deadlocking.
In practice, this busy-looping should be rare:
- for small inputs, we'll just write the whole thing in a single
write() anyway, non-blocking or not
- for larger inputs where the child reads input and then processes it
before writing (e.g., gpg verifying a signature), we may make a few
extra write() calls that get EAGAIN during the initial write, but
once it has taken in the whole input, we'll correctly block waiting
to read back the data.
- for larger inputs where the child process is streaming output back
(like a diff filter), we'll likewise see some extra EAGAINs, but
most of them will be followed immediately by a read(), which will
let the child command make forward progress.
Of course it won't happen at all for now, since we don't yet use a
non-blocking pipe. This is just preparation for when we do.
Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We define MAX_IO_SIZE within wrapper.c, but it's useful for any code
that wants to do a raw write() for whatever reason (say, because they
want different EAGAIN handling). Let's make it available everywhere.
The alternative would be adding xwrite_foo() variants to give callers
more options. But there's really no reason MAX_IO_SIZE needs to be
abstracted away, so this give callers the most flexibility.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement enable_pipe_nonblock() using the Windows API. This works only
for pipes, but that is sufficient for this limited interface. Despite
the API calls used, it handles both "named" and anonymous pipes from our
pipe() emulation.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We'd like to be able to make some of our pipes nonblocking so that
poll() can be used effectively, but O_NONBLOCK isn't portable. Let's
introduce a compat wrapper so this can be abstracted for each platform.
The interface is as narrow as possible to let platforms do what's
natural there (rather than having to implement fcntl() and a fake
O_NONBLOCK for example, or having to handle other types of descriptors).
The next commit will add Windows support, at which point we should be
covering all platforms in practice. But if we do find some other
platform without O_NONBLOCK, we'll return ENOSYS. Arguably we could just
trigger a build-time #error in this case, which would catch the problem
earlier. But since we're not planning to use this compat wrapper in many
code paths, a seldom-seen runtime error may be friendlier for such a
platform than blocking compilation completely. Our test suite would
still notice it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, negotiation for V0/V1/V2 fetch have trace2 regions covering
the entire negotiation process. However, we'd like additional data, such
as timing for each round of negotiation or the number of "haves" in each
round. Additionally, "independent negotiation" (AKA push negotiation)
has no tracing at all. Having this data would allow us to compare the
performance of the various negotation implementations, and to debug
unexpectedly slow fetch & push sessions.
Add per-round trace2 regions for all negotiation implementations (V0+V1,
V2, and independent negotiation), as well as an overall region for
independent negotiation. Add trace2 data logging for the number of haves
and "in vain" objects for each round, and for the total number of rounds
once negotiation completes. Finally, add a few checks into various
tests to verify that the number of rounds is logged as expected.
Signed-off-by: Josh Steadmon <steadmon@google.com>
Acked-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
