Fix a trivial bug that's been here since the shared/do_write_index
tracing was added in 42fee7a3 ("trace2:data: add trace2
instrumentation to index read/write", 2019-02-22). We should have
enter/leave points, not two enter/enter points. This resulted in an
"enter" event without a corresponding "leave" event.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: NDerrick Stolee <dstolee@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Fix trace2_data_json_fl() to check for the presence of pfn_data_json_fl
in its targets, rather than pfn_data_fl, which is not actually called.
Signed-off-by: NJosh Steadmon <steadmon@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Create unit tests for Trace2.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When studying the performance of 'git push' we would like to know
how much time is spent at various parts of the command. One area
that could cause performance trouble is 'git pack-objects'.

Add trace2 regions around the three main actions taken in this
command:

1. Enumerate objects.
2. Prepare pack.
3. Write pack-file.
Signed-off-by: NDerrick Stolee <dstolee@microsoft.com>
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add trace2 events to measure reading and writing the index.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Classify certain child processes as hooks.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add trace2 child classification for transport processes.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add trace2 classification for long-running processes
started in sub-process.c
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add trace2 process classification for editor and pager
child processes.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add trace2_region_enter() and trace2_region_leave() calls around the
various phases of a status scan.  This gives elapsed time for each
phase in the GIT_TR2_PERF and GIT_TR2_EVENT trace target.

Also, these Trace2 calls now use s->repo rather than the_repository.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add platform-specific interface to log information about the current
process.

On Windows, this interface is used to indicate whether the git process
is running under a debugger and list names of the process ancestors.

Information for other platforms is left for a future effort.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Create a new unified tracing facility for git.  The eventual intent is to
replace the current trace_printf* and trace_performance* routines with a
unified set of git_trace2* routines.

In addition to the usual printf-style API, trace2 provides higer-level
event verbs with fixed-fields allowing structured data to be written.
This makes post-processing and analysis easier for external tools.

Trace2 defines 3 output targets.  These are set using the environment
variables "GIT_TR2", "GIT_TR2_PERF", and "GIT_TR2_EVENT".  These may be
set to "1" or to an absolute pathname (just like the current GIT_TRACE).

* GIT_TR2 is intended to be a replacement for GIT_TRACE and logs command
  summary data.

* GIT_TR2_PERF is intended as a replacement for GIT_TRACE_PERFORMANCE.
  It extends the output with columns for the command process, thread,
  repo, absolute and relative elapsed times.  It reports events for
  child process start/stop, thread start/stop, and per-thread function
  nesting.

* GIT_TR2_EVENT is a new structured format. It writes event data as a
  series of JSON records.

Calls to trace2 functions log to any of the 3 output targets enabled
without the need to call different trace_printf* or trace_performance*
routines.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Created design document for Trace2 feature.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* js/test-tool-gen-nuls:
  tests: teach the test-tool to generate NUL bytes and use it

* mk/t5562-no-input-to-too-large-an-input-test:
  t5562: do not depend on /dev/zero
  Revert "t5562: replace /dev/zero with a pipe from generate_zero_bytes"

* mk/t5562-do-not-reuse-output-files:
  t5562: do not reuse output files

Some expected failures of git-http-backend leaves running its children
(receive-pack or upload-pack) which still hold opened descriptors
to act.err and with some probability they live long enough to write
there their failure messages after next test has already truncated
the files. This causes occasional failures of the test script.

Avoid the issue by using separated output and error file for each test,
apprending the test number to their name.
Reported-by: NCarlo Arenas <carenas@gmail.com>
Helped-by: NCarlo Arenas <carenas@gmail.com>
Helped-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NMax Kirillov <max@max630.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In cc95bc20 (t5562: replace /dev/zero with a pipe from
generate_zero_bytes, 2019-02-09), we replaced usage of /dev/zero (which
is not available on NonStop, apparently) by a Perl script snippet to
generate NUL bytes.

Sadly, it does not seem to work on NonStop, as t5562 reportedly hangs.

Worse, this also hangs in the Ubuntu 16.04 agents of the CI builds on
Azure Pipelines: for some reason, the Perl script snippet that is run
via `generate_zero_bytes` in t5562's 'CONTENT_LENGTH overflow ssite_t'
test case tries to write out an infinite amount of NUL bytes unless a
broken pipe is encountered, that snippet never encounters the broken
pipe, and keeps going until the build times out.

Oddly enough, this does not reproduce on the Windows and macOS agents,
nor in a local Ubuntu 18.04.

This developer tried for a day to figure out the exact circumstances
under which this hang happens, to no avail, the details remain a
mystery.

In the end, though, what counts is that this here change incidentally
fixes that hang (maybe also on NonStop?). Even more positively, it gets
rid of yet another unnecessary Perl invocation.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It was reported [1] that NonStop platform does not have /dev/zero.

The test uses /dev/zero as a dummy input. Passing case (http-backed
failed because of too big input size) should not be reading anything
from it. If http-backend would erroneously try to read any data
returning EOF probably would be even safer than providing some
meaningless data.

Replace /dev/zero with /dev/null to avoid issues with platforms which do
not have /dev/zero.

[1] https://public-inbox.org/git/20190209185930.5256-4-randall.s.becker@rogers.com/Reported-by: NRandall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: NMax Kirillov <max@max630.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Revert cc95bc20 ("t5562: replace /dev/zero with a pipe from
generate_zero_bytes", 2019-02-09), as not feeding anything to the
command is a better way to test it.

Running up to v2.21.0, we fixed two bugs that were made prominent by the
Windows-specific change to retain copies of only the 30 latest getenv()
calls' returned strings, invalidating any copies of previous getenv()
calls' return values.

While this really shines a light onto bugs of the form where we hold
onto getenv()'s return values without copying them, it is also a real
problem for users.

And even if Jeff King's patches merged via 773e4088 (Merge branch
'jk/save-getenv-result', 2019-01-29) provide further work on that front,
we are far from done. Just one example: on Windows, we unset environment
variables when spawning new processes, which potentially invalidates
strings that were previously obtained via getenv(), and therefore we
have to duplicate environment values that are somehow involved in
spawning new processes (e.g. GIT_MAN_VIEWER in show_man_page()).

We do not have a chance to investigate, let address, all of those issues
in time for v2.21.0, so let's at least help Windows users by increasing
the number of getenv() calls' return values that are kept valid. The
number 64 was determined by looking at the average number of getenv()
calls per process in the entire test suite run on Windows (which is
around 40) and then adding a bit for good measure. And it is a power of
two (which would have hit yesterday's theme perfectly).
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* ea/rebase-compat-doc-fix:
  docs/git-rebase: remove redundant entry in incompatible options list

* jc/no-grepping-for-strerror-in-tests:
  t1404: do not rely on the exact phrasing of strerror()

"git fetch" and "git upload-pack" learned to send all exchange over
the sideband channel while talking the v2 protocol.

* jt/fetch-v2-sideband:
  t/lib-httpd: pass GIT_TEST_SIDEBAND_ALL through Apache

"git rebase --merge" as been reimplemented by reusing the internal
machinery used for "git rebase -i".

* en/rebase-merge-on-sequencer:
  git-rebase.txt: update to reflect merge now implemented on sequencer

Since commit 8fe9c3f2 (Merge branch 'en/rebase-merge-on-sequencer',
2019-02-06), --merge now uses the interactive backend (and matches its
behavior) so there is no separate merge backend anymore.  Fix an
oversight in the docs that should have been updated with the previous
change.
Signed-off-by: NElijah Newren <newren@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

07c3c2aa ("tests: define GIT_TEST_SIDEBAND_ALL", 2019-01-16) added
GIT_TEST_SIDEBAND_ALL to the apache.conf PassEnv list.  Avoid warnings
from Apache when the variable is unset, as we do for GIT_VALGRIND* and
GIT_TRACE, from f6288254 ("t/lib-httpd: handle running under
--valgrind", 2012-07-24) and 89c57ab3 ("t: pass GIT_TRACE through
Apache", 2015-03-13), respectively.
Signed-off-by: NTodd Zullinger <tmz@pobox.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Not even in C locale, it is wrong to expect that the exact phrasing
"File exists" is used to show EEXIST.
Reported-by: NRandall S. Becker <rsbecker@nexbridge.com>
Helped-by: NDuy Nguyen <pclouds@gmail.com>
Helped-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The --autosquash option is implied by the earlier --[no-]autosquash
entry in the list.
Signed-off-by: NEmilio Cobos Álvarez <emilio@crisal.io>
Reviewed-by: NElijah Newren <newren@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* ab/rebase-test-fix:
  rebase: fix regression in rebase.useBuiltin=false test mode

* rb/no-dev-zero-in-test:
  t5562: replace /dev/zero with a pipe from generate_zero_bytes
  t5318: replace use of /dev/zero with generate_zero_bytes
  test-lib-functions.sh: add generate_zero_bytes function

* rs/bash-is-in-coreutils-on-nonstop:
  config.mak.uname: move location of bash on NonStop to CoreUtils

Windows update.

* js/mingw-host-cpu:
  mingw: use a more canonical method to fix the CPU reporting

Test improvement.

* sg/stress-test:
  test-lib: fix non-portable pattern bracket expressions
  test-lib: make '--stress' more bisect-friendly