view tests/test-url-rev.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

Test basic functionality of url#rev syntax

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg ci -qAm 'add a'
  $ hg branch foo
  marked working directory as branch foo
  (branches are permanent and global, did you want a bookmark?)
  $ echo >> a
  $ hg ci -m 'change a'
  $ cd ..

  $ hg clone 'repo#foo' clone
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  new changesets 1f0dee641bb7:cd2a86ecc814
  updating to branch foo
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg --cwd clone heads
  changeset:   1:cd2a86ecc814
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change a
  
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ hg --cwd clone parents
  changeset:   1:cd2a86ecc814
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change a
  
  $ cat clone/.hg/hgrc
  # example repository config (see 'hg help config' for more info)
  [paths]
  default = $TESTTMP/repo#foo
  
  # path aliases to other clones of this repo in URLs or filesystem paths
  # (see 'hg help config.paths' for more info)
  #
  # default:pushurl = ssh://[e-mail]/hg/jdoes-fork
  # my-fork         = ssh://[e-mail]/hg/jdoes-fork
  # my-clone        = /home/jdoe/jdoes-clone
  
  [ui]
  # name and email (local to this repository, optional), e.g.
  # username = Jane Doe <[e-mail]>

Changing original repo:

  $ cd repo

  $ echo >> a
  $ hg ci -m 'new head of branch foo'

  $ hg up -qC default
  $ echo bar > bar
  $ hg ci -qAm 'add bar'

  $ hg log
  changeset:   3:4cd725637392
  tag:         tip
  parent:      0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add bar
  
  changeset:   2:faba9097cad4
  branch:      foo
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
  changeset:   1:cd2a86ecc814
  branch:      foo
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change a
  
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ hg -q outgoing '../clone'
  2:faba9097cad4
  3:4cd725637392
  $ hg summary --remote --config paths.default='../clone'
  parent: 3:4cd725637392 tip
   add bar
  branch: default
  commit: (clean)
  update: (current)
  phases: 4 draft
  remote: 2 outgoing
  $ hg -q outgoing '../clone#foo'
  2:faba9097cad4
  $ hg summary --remote --config paths.default='../clone#foo'
  parent: 3:4cd725637392 tip
   add bar
  branch: default
  commit: (clean)
  update: (current)
  phases: 4 draft
  remote: 1 outgoing

  $ hg -q --cwd ../clone incoming '../repo#foo'
  2:faba9097cad4
  $ hg --cwd ../clone summary --remote --config paths.default='../repo#foo'
  parent: 1:cd2a86ecc814 tip
   change a
  branch: foo
  commit: (clean)
  update: (current)
  remote: 1 or more incoming

  $ hg -q push '../clone#foo'

  $ hg --cwd ../clone heads
  changeset:   2:faba9097cad4
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ hg -q --cwd ../clone incoming '../repo#foo'
  [1]
  $ hg --cwd ../clone summary --remote --config paths.default='../repo#foo'
  parent: 1:cd2a86ecc814 
   change a
  branch: foo
  commit: (clean)
  update: 1 new changesets (update)
  remote: (synced)

  $ cd ..

  $ cd clone
  $ hg rollback
  repository tip rolled back to revision 1 (undo push)

  $ hg -q incoming
  2:faba9097cad4

  $ hg -q pull

  $ hg heads
  changeset:   2:faba9097cad4
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
Pull should not have updated:

  $ hg parents -q
  1:cd2a86ecc814

Going back to the default branch:

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg parents
  changeset:   0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
No new revs, no update:

  $ hg pull -qu

  $ hg parents -q
  0:1f0dee641bb7

  $ hg rollback
  repository tip rolled back to revision 1 (undo pull)

  $ hg parents -q
  0:1f0dee641bb7

Pull -u takes us back to branch foo:

  $ hg pull -qu

  $ hg parents
  changeset:   2:faba9097cad4
  branch:      foo
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
  $ hg rollback
  repository tip rolled back to revision 1 (undo pull)
  working directory now based on revision 0

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg parents -q
  0:1f0dee641bb7

  $ hg heads -q
  1:cd2a86ecc814
  0:1f0dee641bb7

  $ hg pull -qur default default

  $ hg parents
  changeset:   3:4cd725637392
  tag:         tip
  parent:      0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add bar
  
  $ hg heads
  changeset:   3:4cd725637392
  tag:         tip
  parent:      0:1f0dee641bb7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add bar
  
  changeset:   2:faba9097cad4
  branch:      foo
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     new head of branch foo
  
Test handling of invalid urls

  $ hg id http://foo/?bar
  abort: unsupported URL component: "bar"
  [255]

  $ cd ..

Test handling common incoming revisions between "default" and
"default-push"

  $ hg -R clone rollback
  repository tip rolled back to revision 1 (undo pull)
  working directory now based on revision 0

  $ cd repo

  $ hg update -q -C default
  $ echo modified >> bar
  $ hg commit -m "new head to push current default head"
  $ hg -q push -r ".^1" '../clone'

  $ hg -q outgoing '../clone'
  2:faba9097cad4
  4:d515801a8f3d

  $ hg summary --remote --config paths.default='../clone#default' --config paths.default-push='../clone#foo'
  parent: 4:d515801a8f3d tip
   new head to push current default head
  branch: default
  commit: (clean)
  update: (current)
  phases: 1 draft
  remote: 1 outgoing

  $ hg summary --remote --config paths.default='../clone#foo' --config paths.default-push='../clone'
  parent: 4:d515801a8f3d tip
   new head to push current default head
  branch: default
  commit: (clean)
  update: (current)
  phases: 1 draft
  remote: 2 outgoing

  $ hg summary --remote --config paths.default='../clone' --config paths.default-push='../clone#foo'
  parent: 4:d515801a8f3d tip
   new head to push current default head
  branch: default
  commit: (clean)
  update: (current)
  phases: 1 draft
  remote: 1 outgoing

  $ hg clone -q -r 0 . ../another
  $ hg -q outgoing '../another#default'
  3:4cd725637392
  4:d515801a8f3d

  $ hg summary --remote --config paths.default='../another#default' --config paths.default-push='../clone#default'
  parent: 4:d515801a8f3d tip
   new head to push current default head
  branch: default
  commit: (clean)
  update: (current)
  phases: 1 draft
  remote: 1 outgoing

  $ cd ..

Test url#rev syntax of local destination path, which should be taken as
a 'url#rev' path

  $ hg clone repo '#foo'
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg root -R '#foo'
  $TESTTMP/#foo