view tests/test-uncommit.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 uncommit - set up the config

  $ cat >> $HGRCPATH <<EOF
  > [experimental]
  > evolution.createmarkers=True
  > evolution.allowunstable=True
  > [extensions]
  > uncommit =
  > drawdag=$TESTDIR/drawdag.py
  > EOF

Build up a repo

  $ hg init repo
  $ cd repo
  $ hg bookmark foo

Help for uncommit

  $ hg help uncommit
  hg uncommit [OPTION]... [FILE]...
  
  uncommit part or all of a local changeset
  
      This command undoes the effect of a local commit, returning the affected
      files to their uncommitted state. This means that files modified or
      deleted in the changeset will be left unchanged, and so will remain
      modified in the working directory.
  
      If no files are specified, the commit will be pruned, unless --keep is
      given.
  
  (use 'hg help -e uncommit' to show help for the uncommit extension)
  
  options ([+] can be repeated):
  
      --keep                allow an empty commit after uncommiting
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
  
  (some details hidden, use --verbose to show complete help)

Uncommit with no commits should fail

  $ hg uncommit
  abort: cannot uncommit null changeset
  (no changeset checked out)
  [255]

Create some commits

  $ touch files
  $ hg add files
  $ for i in a ab abc abcd abcde; do echo $i > files; echo $i > file-$i; hg add file-$i; hg commit -m "added file-$i"; done
  $ ls
  file-a
  file-ab
  file-abc
  file-abcd
  file-abcde
  files

  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @  4:6c4fd43ed714e7fcd8adbaa7b16c953c2e985b60 added file-abcde
  |
  o  3:6db330d65db434145c0b59d291853e9a84719b24 added file-abcd
  |
  o  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abc
  |
  o  1:69a232e754b08d568c4899475faf2eb44b857802 added file-ab
  |
  o  0:3004d2d9b50883c1538fc754a3aeb55f1b4084f6 added file-a
  
Simple uncommit off the top, also moves bookmark

  $ hg bookmark
   * foo                       4:6c4fd43ed714
  $ hg uncommit
  $ hg status
  M files
  A file-abcde
  $ hg bookmark
   * foo                       3:6db330d65db4

  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  x  4:6c4fd43ed714e7fcd8adbaa7b16c953c2e985b60 added file-abcde
  |
  @  3:6db330d65db434145c0b59d291853e9a84719b24 added file-abcd
  |
  o  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abc
  |
  o  1:69a232e754b08d568c4899475faf2eb44b857802 added file-ab
  |
  o  0:3004d2d9b50883c1538fc754a3aeb55f1b4084f6 added file-a
  

Recommit

  $ hg commit -m 'new change abcde'
  $ hg status
  $ hg heads -T '{rev}:{node} {desc}'
  5:0c07a3ccda771b25f1cb1edbd02e683723344ef1 new change abcde (no-eol)

Uncommit of non-existent and unchanged files has no effect
  $ hg uncommit nothinghere
  nothing to uncommit
  [1]
  $ hg status
  $ hg uncommit file-abc
  nothing to uncommit
  [1]
  $ hg status

Try partial uncommit, also moves bookmark

  $ hg bookmark
   * foo                       5:0c07a3ccda77
  $ hg uncommit files
  $ hg status
  M files
  $ hg bookmark
   * foo                       6:3727deee06f7
  $ hg heads -T '{rev}:{node} {desc}'
  6:3727deee06f72f5ffa8db792ee299cf39e3e190b new change abcde (no-eol)
  $ hg log -r . -p -T '{rev}:{node} {desc}'
  6:3727deee06f72f5ffa8db792ee299cf39e3e190b new change abcdediff -r 6db330d65db4 -r 3727deee06f7 file-abcde
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file-abcde	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +abcde
  
  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @  6:3727deee06f72f5ffa8db792ee299cf39e3e190b new change abcde
  |
  | x  5:0c07a3ccda771b25f1cb1edbd02e683723344ef1 new change abcde
  |/
  | x  4:6c4fd43ed714e7fcd8adbaa7b16c953c2e985b60 added file-abcde
  |/
  o  3:6db330d65db434145c0b59d291853e9a84719b24 added file-abcd
  |
  o  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abc
  |
  o  1:69a232e754b08d568c4899475faf2eb44b857802 added file-ab
  |
  o  0:3004d2d9b50883c1538fc754a3aeb55f1b4084f6 added file-a
  
  $ hg commit -m 'update files for abcde'

Uncommit with dirty state

  $ echo "foo" >> files
  $ cat files
  abcde
  foo
  $ hg status
  M files
  $ hg uncommit
  abort: uncommitted changes
  [255]
  $ hg uncommit files
  $ cat files
  abcde
  foo
  $ hg commit --amend -m "files abcde + foo"

Testing the 'experimental.uncommitondirtywdir' config

  $ echo "bar" >> files
  $ hg uncommit
  abort: uncommitted changes
  [255]
  $ hg uncommit --config experimental.uncommitondirtywdir=True
  $ hg commit -m "files abcde + foo"

Uncommit in the middle of a stack, does not move bookmark

  $ hg checkout '.^^^'
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  (leaving bookmark foo)
  $ hg log -r . -p -T '{rev}:{node} {desc}'
  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abcdiff -r 69a232e754b0 -r abf2df566fc1 file-abc
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file-abc	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +abc
  diff -r 69a232e754b0 -r abf2df566fc1 files
  --- a/files	Thu Jan 01 00:00:00 1970 +0000
  +++ b/files	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -ab
  +abc
  
  $ hg bookmark
     foo                       10:48e5bd7cd583
  $ hg uncommit
  3 new orphan changesets
  $ hg status
  M files
  A file-abc
  $ hg heads -T '{rev}:{node} {desc}'
  10:48e5bd7cd583eb24164ef8b89185819c84c96ed7 files abcde + foo (no-eol)
  $ hg bookmark
     foo                       10:48e5bd7cd583
  $ hg commit -m 'new abc'
  created new head

Partial uncommit in the middle, does not move bookmark

  $ hg checkout '.^'
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg log -r . -p -T '{rev}:{node} {desc}'
  1:69a232e754b08d568c4899475faf2eb44b857802 added file-abdiff -r 3004d2d9b508 -r 69a232e754b0 file-ab
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file-ab	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +ab
  diff -r 3004d2d9b508 -r 69a232e754b0 files
  --- a/files	Thu Jan 01 00:00:00 1970 +0000
  +++ b/files	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -a
  +ab
  
  $ hg bookmark
     foo                       10:48e5bd7cd583
  $ hg uncommit file-ab
  1 new orphan changesets
  $ hg status
  A file-ab

  $ hg heads -T '{rev}:{node} {desc}\n'
  12:8eb87968f2edb7f27f27fe676316e179de65fff6 added file-ab
  11:5dc89ca4486f8a88716c5797fa9f498d13d7c2e1 new abc
  10:48e5bd7cd583eb24164ef8b89185819c84c96ed7 files abcde + foo

  $ hg bookmark
     foo                       10:48e5bd7cd583
  $ hg commit -m 'update ab'
  $ hg status
  $ hg heads -T '{rev}:{node} {desc}\n'
  13:f21039c59242b085491bb58f591afc4ed1c04c09 update ab
  11:5dc89ca4486f8a88716c5797fa9f498d13d7c2e1 new abc
  10:48e5bd7cd583eb24164ef8b89185819c84c96ed7 files abcde + foo

  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @  13:f21039c59242b085491bb58f591afc4ed1c04c09 update ab
  |
  o  12:8eb87968f2edb7f27f27fe676316e179de65fff6 added file-ab
  |
  | *  11:5dc89ca4486f8a88716c5797fa9f498d13d7c2e1 new abc
  | |
  | | *  10:48e5bd7cd583eb24164ef8b89185819c84c96ed7 files abcde + foo
  | | |
  | | | x  9:8a6b58c173ca6a2e3745d8bd86698718d664bc6c files abcde + foo
  | | |/
  | | | x  8:39ad452c7f684a55d161c574340c5766c4569278 update files for abcde
  | | |/
  | | | x  7:0977fa602c2fd7d8427ed4e7ee15ea13b84c9173 update files for abcde
  | | |/
  | | *  6:3727deee06f72f5ffa8db792ee299cf39e3e190b new change abcde
  | | |
  | | | x  5:0c07a3ccda771b25f1cb1edbd02e683723344ef1 new change abcde
  | | |/
  | | | x  4:6c4fd43ed714e7fcd8adbaa7b16c953c2e985b60 added file-abcde
  | | |/
  | | *  3:6db330d65db434145c0b59d291853e9a84719b24 added file-abcd
  | | |
  | | x  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abc
  | |/
  | x  1:69a232e754b08d568c4899475faf2eb44b857802 added file-ab
  |/
  o  0:3004d2d9b50883c1538fc754a3aeb55f1b4084f6 added file-a
  
Uncommit with draft parent

  $ hg uncommit
  $ hg phase -r .
  12: draft
  $ hg commit -m 'update ab again'

Phase is preserved

  $ hg uncommit --keep --config phases.new-commit=secret
  $ hg phase -r .
  15: draft
  $ hg commit --amend -m 'update ab again'

Uncommit with public parent

  $ hg phase -p "::.^"
  $ hg uncommit
  $ hg phase -r .
  12: public

Partial uncommit with public parent

  $ echo xyz > xyz
  $ hg add xyz
  $ hg commit -m "update ab and add xyz"
  $ hg uncommit xyz
  $ hg status
  A xyz
  $ hg phase -r .
  18: draft
  $ hg phase -r ".^"
  12: public

Uncommit leaving an empty changeset

  $ cd $TESTTMP
  $ hg init repo1
  $ cd repo1
  $ hg debugdrawdag <<'EOS'
  > Q
  > |
  > P
  > EOS
  $ hg up Q -q
  $ hg uncommit --keep
  $ hg log -G -T '{desc} FILES: {files}'
  @  Q FILES:
  |
  | x  Q FILES: Q
  |/
  o  P FILES: P
  
  $ hg status
  A Q

  $ cd ..
  $ rm -rf repo1

Testing uncommit while merge

  $ hg init repo2
  $ cd repo2

Create some history

  $ touch a
  $ hg add a
  $ for i in 1 2 3; do echo $i > a; hg commit -m "a $i"; done
  $ hg checkout 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ touch b
  $ hg add b
  $ for i in 1 2 3; do echo $i > b; hg commit -m "b $i"; done
  created new head
  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @  5:2cd56cdde163ded2fbb16ba2f918c96046ab0bf2 b 3
  |
  o  4:c3a0d5bb3b15834ffd2ef9ef603e93ec65cf2037 b 2
  |
  o  3:49bb009ca26078726b8870f1edb29fae8f7618f5 b 1
  |
  | o  2:990982b7384266e691f1bc08ca36177adcd1c8a9 a 3
  | |
  | o  1:24d38e3cf160c7b6f5ffe82179332229886a6d34 a 2
  |/
  o  0:ea4e33293d4d274a2ba73150733c2612231f398c a 1
  

Add and expect uncommit to fail on both merge working dir and merge changeset

  $ hg merge 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg uncommit
  abort: outstanding uncommitted merge
  [255]

  $ hg uncommit --config experimental.uncommitondirtywdir=True
  abort: cannot uncommit while merging
  [255]

  $ hg status
  M a
  $ hg commit -m 'merge a and b'

  $ hg uncommit
  abort: cannot uncommit merge changeset
  [255]

  $ hg status
  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @    6:c03b9c37bc67bf504d4912061cfb527b47a63c6e merge a and b
  |\
  | o  5:2cd56cdde163ded2fbb16ba2f918c96046ab0bf2 b 3
  | |
  | o  4:c3a0d5bb3b15834ffd2ef9ef603e93ec65cf2037 b 2
  | |
  | o  3:49bb009ca26078726b8870f1edb29fae8f7618f5 b 1
  | |
  o |  2:990982b7384266e691f1bc08ca36177adcd1c8a9 a 3
  | |
  o |  1:24d38e3cf160c7b6f5ffe82179332229886a6d34 a 2
  |/
  o  0:ea4e33293d4d274a2ba73150733c2612231f398c a 1