tests/test-dirstate-status-write-race.t

dirstate: tests racing status with both dirstate-v2 append and rewrite

The way the racing process touches the dirstate results in different challenges
for the raced process.

We now test each variant in the `test-dirstate-status-race.t` tests.

=====================================================================
Check potential race conditions between a status and other operations
=====================================================================

#testcases dirstate-v1 dirstate-v2-append dirstate-v2-rewrite

The `hg status` command can run without the wlock, however it might end up
having to update the on-disk dirstate files, for example to mark ambiguous
files as clean, or to update directory caches information with dirstate-v2.


If another process updates the dirstate in the meantime we might run into
trouble. Especially, commands doing semantic changes like `hg add` or
 `hg commit` should not see their update erased by a concurrent status.

Unlike commands like `add` or `commit`, `status` only writes the dirstate
to update caches, no actual information is lost if we fail to write to disk.


This test file is meant to test various cases where such parallel operations
between a status with reasons to update the dirstate and another semantic
changes happen.


Setup
=====

  $ cat >> $HGRCPATH << EOF
  > [storage]
  > dirstate-v2.slow-path=allow
  > EOF

#if no-dirstate-v1
  $ cat >> $HGRCPATH << EOF
  > [format]
  > use-dirstate-v2=yes
  > EOF
#else
  $ cat >> $HGRCPATH << EOF
  > [format]
  > use-dirstate-v2=no
  > EOF
#endif

#if dirstate-v2-rewrite
  $ d2args="--config devel.dirstate.v2.data_update_mode=force-new"
#endif
#if dirstate-v2-append
  $ d2args="--config devel.dirstate.v2.data_update_mode=force-append"
#endif

  $ directories="dir dir/nested dir2"
  $ first_files="dir/nested/a dir/b dir/c dir/d dir2/e f"
  $ second_files="g dir/nested/h dir/i dir/j dir2/k dir2/l dir/nested/m"
  $ extra_files="dir/n dir/o p q"

  $ hg init reference-repo
  $ cd reference-repo
  $ mkdir -p dir/nested dir2
  $ touch -t 200001010000 $first_files $directories
  $ hg commit -Aqm "recreate a bunch of files to facilitate dirstate-v2 append"
  $ touch -t 200001010010 $second_files $directories
  $ hg commit -Aqm "more files to have two commits"
  $ hg log -G -v
  @  changeset:   1:c349430a1631
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  files:       dir/i dir/j dir/nested/h dir/nested/m dir2/k dir2/l g
  |  description:
  |  more files to have two commits
  |
  |
  o  changeset:   0:4f23db756b09
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     files:       dir/b dir/c dir/d dir/nested/a dir2/e f
     description:
     recreate a bunch of files to facilitate dirstate-v2 append
  
  
  $ hg manifest
  dir/b
  dir/c
  dir/d
  dir/i
  dir/j
  dir/nested/a
  dir/nested/h
  dir/nested/m
  dir2/e
  dir2/k
  dir2/l
  f
  g

Add some unknown files and refresh the dirstate

  $ touch -t 200001010020 $extra_files
  $ hg add dir/o
  $ hg remove dir/nested/m

  $ hg st --config devel.dirstate.v2.data_update_mode=force-new
  A dir/o
  R dir/nested/m
  ? dir/n
  ? p
  ? q
  $ hg debugstate
  n 644          0 2000-01-01 00:00:00 dir/b
  n 644          0 2000-01-01 00:00:00 dir/c
  n 644          0 2000-01-01 00:00:00 dir/d
  n 644          0 2000-01-01 00:10:00 dir/i
  n 644          0 2000-01-01 00:10:00 dir/j
  n 644          0 2000-01-01 00:00:00 dir/nested/a
  n 644          0 2000-01-01 00:10:00 dir/nested/h
  r ?????????????????????????????????? dir/nested/m (glob)
  a ?????????????????????????????????? dir/o (glob)
  n 644          0 2000-01-01 00:00:00 dir2/e
  n 644          0 2000-01-01 00:10:00 dir2/k
  n 644          0 2000-01-01 00:10:00 dir2/l
  n 644          0 2000-01-01 00:00:00 f
  n 644          0 2000-01-01 00:10:00 g
  $ hg debugstate > ../reference
  $ cd ..

Explain / verify the test principles
------------------------------------

First, we can properly copy the reference

  $ cp -a reference-repo sanity-check
  $ cd sanity-check
  $ hg debugstate
  n 644          0 2000-01-01 00:00:00 dir/b
  n 644          0 2000-01-01 00:00:00 dir/c
  n 644          0 2000-01-01 00:00:00 dir/d
  n 644          0 2000-01-01 00:10:00 dir/i
  n 644          0 2000-01-01 00:10:00 dir/j
  n 644          0 2000-01-01 00:00:00 dir/nested/a
  n 644          0 2000-01-01 00:10:00 dir/nested/h
  r ?????????????????????????????????? dir/nested/m (glob)
  a ?????????????????????????????????? dir/o (glob)
  n 644          0 2000-01-01 00:00:00 dir2/e
  n 644          0 2000-01-01 00:10:00 dir2/k
  n 644          0 2000-01-01 00:10:00 dir2/l
  n 644          0 2000-01-01 00:00:00 f
  n 644          0 2000-01-01 00:10:00 g
  $ hg debugstate > ../post-copy
  $ diff ../reference ../post-copy

And status thinks the cache is in a proper state

  $ hg st
  A dir/o
  R dir/nested/m
  ? dir/n
  ? p
  ? q
  $ hg debugstate
  n 644          0 2000-01-01 00:00:00 dir/b
  n 644          0 2000-01-01 00:00:00 dir/c
  n 644          0 2000-01-01 00:00:00 dir/d
  n 644          0 2000-01-01 00:10:00 dir/i
  n 644          0 2000-01-01 00:10:00 dir/j
  n 644          0 2000-01-01 00:00:00 dir/nested/a
  n 644          0 2000-01-01 00:10:00 dir/nested/h
  r ?????????????????????????????????? dir/nested/m (glob)
  a ?????????????????????????????????? dir/o (glob)
  n 644          0 2000-01-01 00:00:00 dir2/e
  n 644          0 2000-01-01 00:10:00 dir2/k
  n 644          0 2000-01-01 00:10:00 dir2/l
  n 644          0 2000-01-01 00:00:00 f
  n 644          0 2000-01-01 00:10:00 g
  $ hg debugstate > ../post-status
  $ diff ../reference ../post-status

Then we can start a status that:
- has some update to do (the touch call)
- will wait AFTER running status, but before updating the cache on disk

  $ touch -t 200001010001 dir/c
  $ hg st >$TESTTMP/status-race-lock.out 2>$TESTTMP/status-race-lock.log \
  > --config rhg.on-unsupported=abort \
  > --config devel.sync.status.pre-dirstate-write-file=$TESTTMP/status-race-lock \
  > &
  $ $RUNTESTDIR/testlib/wait-on-file 5 $TESTTMP/status-race-lock.waiting

We check it runs the status first by modifying a file and updating another timestamp

  $ touch -t 200001010003 dir/i
  $ echo babar > dir/j
  $ touch $TESTTMP/status-race-lock
  $ wait

The test process should have reported a status before the change we made,
and should have missed the timestamp update

  $ cat $TESTTMP/status-race-lock.out
  A dir/o
  R dir/nested/m
  ? dir/n
  ? p
  ? q
  $ cat $TESTTMP/status-race-lock.log
  $ hg debugstate | grep dir/c
  n 644          0 2000-01-01 00:01:00 dir/c
  $ hg debugstate | grep dir/i
  n 644          0 2000-01-01 00:10:00 dir/i
  $ hg debugstate | grep dir/j
  n 644          0 2000-01-01 00:10:00 dir/j

final cleanup

  $ rm $TESTTMP/status-race-lock $TESTTMP/status-race-lock.waiting
  $ cd ..

Actual Testing
==============

Race with a `hg add`
-------------------

  $ cp -a reference-repo race-with-add
  $ cd race-with-add

spin a `hg status` with some caches to update

  $ touch -t 200001020001 f
  $ hg st >$TESTTMP/status-race-lock.out 2>$TESTTMP/status-race-lock.log \
  > --config rhg.on-unsupported=abort \
  > --config devel.sync.status.pre-dirstate-write-file=$TESTTMP/status-race-lock \
  > &
  $ $RUNTESTDIR/testlib/wait-on-file 5 $TESTTMP/status-race-lock.waiting

Add a file

  $ hg $d2args add dir/n
  $ touch $TESTTMP/status-race-lock
  $ wait

The file should in a "added" state

  $ hg status
  A dir/n (no-rhg !)
  A dir/n (rhg dirstate-v2-rewrite !)
  A dir/n (missing-correct-output rhg dirstate-v1 !)
  A dir/o
  R dir/nested/m
  ? dir/n (known-bad-output rhg no-dirstate-v2-rewrite !)
  ? p
  ? q

The status process should return a consistent result and not crash.

  $ cat $TESTTMP/status-race-lock.out
  A dir/o
  R dir/nested/m
  ? dir/n
  ? p
  ? q
  $ cat $TESTTMP/status-race-lock.log
  abort: when writing $TESTTMP/race-with-add/.hg/dirstate.*: $ENOENT$ (glob) (known-bad-output rhg dirstate-v2-rewrite !)

final cleanup

  $ rm $TESTTMP/status-race-lock $TESTTMP/status-race-lock.waiting
  $ cd ..

Race with a `hg commit`
----------------------

  $ cp -a reference-repo race-with-commit
  $ cd race-with-commit

spin a `hg status` with some caches to update

  $ touch -t 200001020001 dir/j
  $ hg st >$TESTTMP/status-race-lock.out 2>$TESTTMP/status-race-lock.log \
  > --config rhg.on-unsupported=abort \
  > --config devel.sync.status.pre-dirstate-write-file=$TESTTMP/status-race-lock \
  > &
  $ $RUNTESTDIR/testlib/wait-on-file 5 $TESTTMP/status-race-lock.waiting

Add a file and force the data file rewrite

  $ hg $d2args commit -m created-during-status dir/o
  $ touch $TESTTMP/status-race-lock
  $ wait

The parent must change and the status should be clean

# XXX rhg misbehaves here
#if no-rhg
  $ hg summary
  parent: 2:2e3b442a2fd4 tip
   created-during-status
  branch: default
  commit: 1 removed, 3 unknown
  update: (current)
  phases: 3 draft
  $ hg status
  R dir/nested/m
  ? dir/n
  ? p
  ? q
#else
  $ hg summary
  parent: 1:c349430a1631 
   more files to have two commits
  branch: default
  commit: 1 added, 1 removed, 3 unknown (new branch head)
  update: 1 new changesets (update)
  phases: 3 draft
  $ hg status
  A dir/o
  R dir/nested/m
  ? dir/n
  ? p
  ? q
#endif

The status process should return a consistent result and not crash.

  $ cat $TESTTMP/status-race-lock.out
  A dir/o
  R dir/nested/m
  ? dir/n
  ? p
  ? q
  $ cat $TESTTMP/status-race-lock.log
  abort: when removing $TESTTMP/race-with-commit/.hg/dirstate.*: $ENOENT$ (glob) (known-bad-output rhg dirstate-v2-rewrite !)

final cleanup

  $ rm $TESTTMP/status-race-lock $TESTTMP/status-race-lock.waiting
  $ cd ..

Race with a `hg update`
----------------------

  $ cp -a reference-repo race-with-update
  $ cd race-with-update

spin a `hg status` with some caches to update

  $ touch -t 200001020001 dir2/k
  $ hg st >$TESTTMP/status-race-lock.out 2>$TESTTMP/status-race-lock.log \
  > --config rhg.on-unsupported=abort \
  > --config devel.sync.status.pre-dirstate-write-file=$TESTTMP/status-race-lock \
  > &
  $ $RUNTESTDIR/testlib/wait-on-file 5 $TESTTMP/status-race-lock.waiting

Add a file and force the data file rewrite

  $ hg $d2args update ".~1"
  0 files updated, 0 files merged, 6 files removed, 0 files unresolved
  $ touch $TESTTMP/status-race-lock
  $ wait

The parent must change and the status should be clean

  $ hg summary
  parent: 0:4f23db756b09 
   recreate a bunch of files to facilitate dirstate-v2 append
  branch: default
  commit: 1 added, 3 unknown (new branch head)
  update: 1 new changesets (update)
  phases: 2 draft
  $ hg status
  A dir/o
  ? dir/n
  ? p
  ? q

The status process should return a consistent result and not crash.

  $ cat $TESTTMP/status-race-lock.out
  A dir/o
  R dir/nested/m
  ? dir/n
  ? p
  ? q
  $ cat $TESTTMP/status-race-lock.log
  abort: when reading $TESTTMP/race-with-update/dir2/k: $ENOENT$ (known-bad-output rhg !)

final cleanup

  $ rm $TESTTMP/status-race-lock $TESTTMP/status-race-lock.waiting
  $ cd ..

Race with another status
------------------------

  $ cp -a reference-repo race-with-status
  $ cd race-with-status

spin a `hg status` with some caches to update

  $ touch -t 200001010030 dir/nested/h
  $ hg st >$TESTTMP/status-race-lock.out 2>$TESTTMP/status-race-lock.log \
  > --config rhg.on-unsupported=abort \
  > --config devel.sync.status.pre-dirstate-write-file=$TESTTMP/status-race-lock \
  > &
  $ $RUNTESTDIR/testlib/wait-on-file 5 $TESTTMP/status-race-lock.waiting

touch g

  $ touch -t 200001010025 g
  $ hg $d2args status
  A dir/o
  R dir/nested/m
  ? dir/n
  ? p
  ? q
  $ touch $TESTTMP/status-race-lock
  $ wait

the first update should be on disk

  $ hg debugstate --all | grep "g"
  n 644          0 2000-01-01 00:25:00 g (no-rhg !)
  n 644          0 2000-01-01 00:25:00 g (missing-correct-output rhg !)
  n 644          0 2000-01-01 00:10:00 g (known-bad-output rhg !)

The status process should return a consistent result and not crash.

  $ cat $TESTTMP/status-race-lock.out
  A dir/o
  R dir/nested/m
  ? dir/n
  ? p
  ? q
  $ cat $TESTTMP/status-race-lock.log
  abort: when removing $TESTTMP/race-with-status/.hg/dirstate.*: $ENOENT$ (glob) (known-bad-output rhg dirstate-v2-rewrite !)

final cleanup

  $ rm $TESTTMP/status-race-lock $TESTTMP/status-race-lock.waiting
  $ cd ..