view tests/test-eolfilename.t @ 38732:be4984261611

merge: mark file gets as not thread safe (issue5933)

In default installs, this has the effect of disabling the thread-based
worker on Windows when manifesting files in the working directory. My
measurements have shown that with revlog-based repositories, Mercurial
spends a lot of CPU time in revlog code resolving file data. This ends
up incurring a lot of context switching across threads and slows down
`hg update` operations when going from an empty working directory to
the tip of the repo.

On mozilla-unified (246,351 files) on an i7-6700K (4+4 CPUs):

before: 487s wall
after:  360s wall (equivalent to worker.enabled=false)
cpus=2: 379s wall

Even with only 2 threads, the thread pool is still slower.

The introduction of the thread-based worker (02b36e860e0b) states that
it resulted in a "~50%" speedup for `hg sparse --enable-profile` and
`hg sparse --disable-profile`. This disagrees with my measurement
above. I theorize a few reasons for this:

1) Removal of files from the working directory is I/O - not CPU - bound
   and should benefit from a thread pool (unless I/O is insanely fast
   and the GIL release is near instantaneous). So tests like `hg sparse
   --enable-profile` may exercise deletion throughput and aren't good
   benchmarks for worker tasks that are CPU heavy.
2) The patch was authored by someone at Facebook. The results were
   likely measured against a repository using remotefilelog. And I
   believe that revision retrieval during working directory updates with
   remotefilelog will often use a remote store, thus being I/O and not
   CPU bound. This probably resulted in an overstated performance gain.

Since there appears to be a need to enable the thread-based worker with
some stores, I've made the flagging of file gets as thread safe
configurable. I've made it experimental because I don't want to formalize
a boolean flag for this option and because this attribute is best
captured against the store implementation. But we don't have a proper
store API for this yet. I'd rather cross this bridge later.

It is possible there are revlog-based repositories that do benefit from
a thread-based worker. I didn't do very comprehensive testing. If there
are, we may want to devise a more proper algorithm for whether to use
the thread-based worker, including possibly config options to limit the
number of threads to use. But until I see evidence that justifies
complexity, simplicity wins.

Differential Revision: https://phab.mercurial-scm.org/D3963

#require eol-in-paths

https://bz.mercurial-scm.org/352

test issue352

  $ hg init foo
  $ cd foo
  $ A=`printf 'he\rllo'`
  $ echo foo > "$A"
  $ hg add
  adding he\r (no-eol) (esc)
  llo
  abort: '\n' and '\r' disallowed in filenames: 'he\rllo'
  [255]
  $ hg ci -A -m m
  adding he\r (no-eol) (esc)
  llo
  abort: '\n' and '\r' disallowed in filenames: 'he\rllo'
  [255]
  $ rm "$A"
  $ echo foo > "hell
  > o"
  $ hg add
  adding hell
  o
  abort: '\n' and '\r' disallowed in filenames: 'hell\no'
  [255]
  $ hg ci -A -m m
  adding hell
  o
  abort: '\n' and '\r' disallowed in filenames: 'hell\no'
  [255]
  $ echo foo > "$A"
  $ hg debugwalk -v
  * matcher:
  <alwaysmatcher>
  f  he\r (no-eol) (esc)
  llo  he\r (no-eol) (esc)
  llo
  f  hell
  o  hell
  o

  $ echo bla > quickfox
  $ hg add quickfox
  $ hg ci -m 2
  $ A=`printf 'quick\rfox'`
  $ hg cp quickfox "$A"
  abort: '\n' and '\r' disallowed in filenames: 'quick\rfox'
  [255]
  $ hg mv quickfox "$A"
  abort: '\n' and '\r' disallowed in filenames: 'quick\rfox'
  [255]

https://bz.mercurial-scm.org/2036

  $ cd ..

test issue2039

  $ hg init bar
  $ cd bar
  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > color =
  > [color]
  > mode = ansi
  > EOF
  $ A=`printf 'foo\nbar'`
  $ B=`printf 'foo\nbar.baz'`
  $ touch "$A"
  $ touch "$B"
  $ hg status --color=always
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mfoo\x1b[0m (esc)
  \x1b[0;35;1;4mbar\x1b[0m (esc)
  \x1b[0;35;1;4m? \x1b[0m\x1b[0;35;1;4mfoo\x1b[0m (esc)
  \x1b[0;35;1;4mbar.baz\x1b[0m (esc)

  $ cd ..