view tests/test-locate.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

  $ hg init repo
  $ cd repo
  $ echo 0 > a
  $ echo 0 > b
  $ echo 0 > t.h
  $ mkdir t
  $ echo 0 > t/x
  $ echo 0 > t/b
  $ echo 0 > t/e.h
  $ mkdir dir.h
  $ echo 0 > dir.h/foo

  $ hg ci -A -m m
  adding a
  adding b
  adding dir.h/foo
  adding t.h
  adding t/b
  adding t/e.h
  adding t/x

  $ touch nottracked

  $ hg locate a
  a

  $ hg locate NONEXISTENT
  [1]

  $ hg locate
  a
  b
  dir.h/foo
  t.h
  t/b
  t/e.h
  t/x

  $ hg rm a
  $ hg ci -m m

  $ hg locate a
  [1]
  $ hg locate NONEXISTENT
  [1]
  $ hg locate relpath:NONEXISTENT
  [1]
  $ hg locate
  b
  dir.h/foo
  t.h
  t/b
  t/e.h
  t/x
  $ hg locate -r 0 a
  a
  $ hg locate -r 0 NONEXISTENT
  [1]
  $ hg locate -r 0 relpath:NONEXISTENT
  [1]
  $ hg locate -r 0
  a
  b
  dir.h/foo
  t.h
  t/b
  t/e.h
  t/x

-I/-X with relative path should work:

  $ cd t
  $ hg locate
  b
  dir.h/foo
  t.h
  t/b
  t/e.h
  t/x
  $ hg locate -I ../t
  t/b
  t/e.h
  t/x

Issue294: hg remove --after dir fails when dir.* also exists

  $ cd ..
  $ rm -r t

  $ hg rm t/b

  $ hg locate 't/**'
  t/b
  t/e.h
  t/x

  $ hg files
  b
  dir.h/foo
  t.h
  t/e.h
  t/x
  $ hg files b
  b

-X with explicit path:

  $ hg files b -X b
  [1]

  $ mkdir otherdir
  $ cd otherdir

  $ hg files path:
  ../b
  ../dir.h/foo
  ../t.h
  ../t/e.h
  ../t/x
  $ hg files path:.
  ../b
  ../dir.h/foo
  ../t.h
  ../t/e.h
  ../t/x

  $ hg locate b
  ../b
  ../t/b
  $ hg locate '*.h'
  ../t.h
  ../t/e.h
  $ hg locate path:t/x
  ../t/x
  $ hg locate 're:.*\.h$'
  ../t.h
  ../t/e.h
  $ hg locate -r 0 b
  ../b
  ../t/b
  $ hg locate -r 0 '*.h'
  ../t.h
  ../t/e.h
  $ hg locate -r 0 path:t/x
  ../t/x
  $ hg locate -r 0 're:.*\.h$'
  ../t.h
  ../t/e.h

  $ hg files
  ../b
  ../dir.h/foo
  ../t.h
  ../t/e.h
  ../t/x
  $ hg files .
  [1]

Convert native path separator to slash (issue5572)

  $ hg files -T '{path|slashpath}\n'
  ../b
  ../dir.h/foo
  ../t.h
  ../t/e.h
  ../t/x

  $ cd ../..