FUJIWARA Katsunori <foozy@lares.dti.ne.jp> [Wed, 08 Jul 2015 17:01:09 +0900] rev 25758
cmdutil: put recordfunc invocation into wlock scope for consistency
Before this patch, 'recordfunc()' for interactive hunk selection does
below outside wlock scope at 'hg commit -i' and so on:
- backup files, which may be partially changed
- apply selected hunks on files
- restore files from backup-ed ones
These should be executed inside wlock scope for consistency.
To put them into wlock scope without largely changing indents in
'recordfunc()', this patch adds another wrapper function.
This patch is also a preparation for subsequent patch fixing the issue
to correctly recognize partially committed files as "modified".
FUJIWARA Katsunori <foozy@lares.dti.ne.jp> [Wed, 08 Jul 2015 17:01:09 +0900] rev 25757
context: write dirstate out explicitly at the end of markcommitted
To detect change of a file without redundant comparison of file
content, dirstate recognizes a file as certainly clean, if:
(1) it is already known as "normal",
(2) dirstate entry for it has valid (= not "-1") timestamp, and
(3) mode, size and timestamp of it on the filesystem are as same as
ones expected in dirstate
This works as expected in many cases, but doesn't in the corner case
that changing a file keeps mode, size and timestamp of it on the
filesystem.
The timetable below shows steps in one of typical such situations:
---- ----------------------------------- ----------------
timestamp of "f"
----------------
dirstate file-
time action mem file system
---- ----------------------------------- ---- ----- -----
* *** ***
- 'hg transplant REV1 REV2 ...'
- transplanting REV1
....
N
- change "f", but keep size N
(via 'patch.patch()')
- 'dirstate.normal("f")' N ***
(via 'repo.commit()')
- transplanting REV2
- change "f", but keep size N
(via 'patch.patch()')
- aborted while patching
N+1
- release wlock
- 'dirstate.write()' N N N
- 'hg status' shows "r1" as "clean" N N N
---- ----------------------------------- ---- ----- -----
The most important point is that 'dirstate.write()' is executed at N+1
or later. This causes writing dirstate timestamp N of "f" out
successfully. If it is executed at N, 'parsers.pack_dirstate()'
replaces timestamp N with "-1" before actual writing dirstate out.
This issue can occur when 'hg transplant' satisfies conditions below:
- multiple revisions to be transplanted change the same file
- those revisions don't change mode and size of the file, and
- the 2nd or later revision of them fails after changing the file
The root cause of this issue is that files are changed without
flushing in-memory dirstate changes via 'repo.commit()' (even though
omitting 'dirstate.normallookup()' on files changed by 'patch.patch()'
for efficiency also causes this issue).
To detect changes of files correctly, this patch writes in-memory
dirstate changes out explicitly after marking files as clean in
'committablectx.markcommitted()', which is invoked via
'repo.commit()'.
After this change, timetable is changed as below:
---- ----------------------------------- ----------------
timestamp of "f"
----------------
dirstate file-
time action mem file system
---- ----------------------------------- ---- ----- -----
* *** ***
- 'hg transplant REV1 REV2 ...'
- transplanting REV1
....
N
- change "f", but keep size N
(via 'patch.patch()')
- 'dirstate.normal("f")' N ***
(via 'repo.commit()')
----------------------------------- ---- ----- -----
- 'dirsttate.write()' -1 -1
----------------------------------- ---- ----- -----
- transplanting REV2
- change "f", but keep size N
(via 'patch.patch()')
- aborted while patching
N+1
- release wlock
- 'dirstate.write()' -1 -1 N
- 'hg status' shows "r1" as "clean" -1 -1 N
---- ----------------------------------- ---- ----- -----
To reproduce this issue in tests certainly, this patch emulates some
timing critical actions as below:
- change "f" at N
'patch.patch()' with 'fakepatchtime.py' explicitly changes mtime
of patched files to "2000-01-01 00:00" (= N).
- 'dirstate.write()' via 'repo.commit()' at N
'fakedirstatewritetime.py' forces 'pack_dirstate()' to use
"2000-01-01 00:00" as "now", only if 'pack_dirstate()' is invoked
via 'committablectx.markcommitted()'.
- 'dirstate.write()' via releasing wlock at N+1 (or "not at N")
'pack_dirstate()' via releasing wlock uses actual timestamp at
runtime as "now", and it should be different from the "2000-01-01
00:00" of "f".
BTW, this patch doesn't test cases below, even though 'patch.patch()'
is used similarly in these cases:
1. failure of 'hg import' or 'hg qpush'
2. success of 'hg import', 'hg qpush' or 'hg transplant'
Case (1) above doesn't cause this kind of issue, because:
- if patching is aborted by conflicts, changed files are committed
changed files are marked as CLEAN, even though they are partially
patched.
- otherwise, dirstate are fully restored by 'dirstateguard'
For example in timetable above, timestamp of "f" in .hg/dirstate
is restored to -1 (or less than N), and subsequent 'hg status' can
detect changes correctly.
Case (2) always causes 'repo.status()' invocation via 'repo.commit()'
just after changing files inside same wlock scope.
---- ----------------------------------- ----------------
timestamp of "f"
----------------
dirstate file-
time action mem file system
---- ----------------------------------- ---- ----- -----
N *** ***
- make file "f" clean N
- execute 'hg foobar'
....
- 'dirstate.normal("f")' N ***
(e.g. via dirty check
or previous 'repo.commit()')
- change "f", but keep size N
- 'repo.status()' (*1)
(via 'repo.commit()')
---- ----------------------------------- ---- ----- -----
At a glance, 'repo.status()' at (*1) seems to cause similar issue (=
"changed files are treated as clean"), but actually doesn't.
'dirstate._lastnormaltime' should be N at (*1) above, because
'dirstate.normal()' via dirty check is finished at N.
Therefore, "f" changed at N (= 'dirstate._lastnormaltime') is forcibly
treated as "unsure" at (*1), and changes are detected as expected (see
'dirstate.status()' for detail).
If 'hg import' is executed with '--no-commit', 'repo.status()' isn't
invoked just after changing files inside same wlock scope.
But preceding 'dirstate.normal()' is invoked inside another wlock
scope via 'cmdutil.bailifchanged()', and in-memory changes should be
flushed at the end of that scope.
Therefore, timestamp N of clean "f" should be replaced by -1, if
'dirstate.write()' is invoked at N. It means that condition of this
issue isn't satisfied.
FUJIWARA Katsunori <foozy@lares.dti.ne.jp> [Wed, 08 Jul 2015 17:01:09 +0900] rev 25756
tests: add extension to emulate invoking internalpatch at the specific time
This extension fakes "mtime" of patched files to emulate invoking
'patch.internalpatch()' at the specific time.
This is useful to reproduce timing critical issues fixed in subsequent
patches.
FUJIWARA Katsunori <foozy@lares.dti.ne.jp> [Wed, 08 Jul 2015 17:01:09 +0900] rev 25755
cmdutil: remove useless dirstate.normallookup() invocation in revert()
Explicit 'dirstate.normallookup()' invocation in 'revert()' is useless
now, because previous patch fixed the relevant issue by writing
in-memory dirstate changes out at the end of dirty check.
'dirstate.normallookup()' invocation was introduced by
21b33f0460e0 to
avoid occasional test failure (see
issue4583 for detail). This is
partial backout of it (added tests are still left).
FUJIWARA Katsunori <foozy@lares.dti.ne.jp> [Wed, 08 Jul 2015 17:01:09 +0900] rev 25754
merge: remove useless dirstate.normallookup() invocation in applyupdates()
Explicit 'dirstate.normallookup()' invocation via 'dirtysubstate()' in
'applyupdates()' is useless now, because previous patch fixed the
relevant issue by writing in-memory dirstate changes out at the end of
dirty check.
'dirstate.normallookup()' invocation was introduced by
6becb9dbca25 to
avoid occasional test failure. This is partial backout of it (added
tests are still left).
FUJIWARA Katsunori <foozy@lares.dti.ne.jp> [Wed, 08 Jul 2015 17:01:09 +0900] rev 25753
context: write dirstate out explicitly after marking files as clean
To detect change of a file without redundant comparison of file
content, dirstate recognizes a file as certainly clean, if:
(1) it is already known as "normal",
(2) dirstate entry for it has valid (= not "-1") timestamp, and
(3) mode, size and timestamp of it on the filesystem are as same as
ones expected in dirstate
This works as expected in many cases, but doesn't in the corner case
that changing a file keeps mode, size and timestamp of it on the
filesystem.
The timetable below shows steps in one of typical such situations:
---- ----------------------------------- ----------------
timestamp of "f"
----------------
dirstate file-
time action mem file system
---- ----------------------------------- ---- ----- -----
N -1 ***
- make file "f" clean N
- execute 'hg foobar'
- instantiate 'dirstate' -1 -1
- 'dirstate.normal("f")' N -1
(e.g. via dirty check)
- change "f", but keep size N
N+1
- release wlock
- 'dirstate.write()' N N
- 'hg status' shows "f" as "clean" N N N
---- ----------------------------------- ---- ----- -----
The most important point is that 'dirstate.write()' is executed at N+1
or later. This causes writing dirstate timestamp N of "f" out
successfully. If it is executed at N, 'parsers.pack_dirstate()'
replaces timestamp N with "-1" before actual writing dirstate out.
Occasional test failure for unexpected file status is typical example
of this corner case. Batch execution with small working directory is
finished in no time, and rarely satisfies condition (2) above.
This issue can occur in cases below;
- 'hg revert --rev REV' for revisions other than the parent
- failure of 'merge.update()' before 'merge.recordupdates()'
The root cause of this issue is that files are changed without
flushing in-memory dirstate changes via 'repo.commit()' (even though
omitting 'dirstate.normallookup()' on changed files also causes this
issue).
To detect changes of files correctly, this patch writes in-memory
dirstate changes out explicitly after marking files as clean in
'workingctx._checklookup()', which is invoked via 'repo.status()'.
After this change, timetable is changed as below:
---- ----------------------------------- ----------------
timestamp of "f"
----------------
dirstate file-
time action mem file system
---- ----------------------------------- ---- ----- -----
N -1 ***
- make file "f" clean N
- execute 'hg foobar'
- instantiate 'dirstate' -1 -1
- 'dirstate.normal("f")' N -1
(e.g. via dirty check)
----------------------------------- ---- ----- -----
- 'dirsttate.write()' -1 -1
----------------------------------- ---- ----- -----
- change "f", but keep size N
N+1
- release wlock
- 'dirstate.write()' -1 -1
- 'hg status' -1 -1 N
---- ----------------------------------- ---- ----- -----
To reproduce this issue in tests certainly, this patch emulates some
timing critical actions as below:
- timestamp of "f" in '.hg/dirstate' is -1 at the beginning
'hg debugrebuildstate' before command invocation ensures it.
- make file "f" clean at N
- change "f" at N
'touch -t
200001010000' before and after command invocation
changes mtime of "f" to "2000-01-01 00:00" (= N).
- invoke 'dirstate.write()' via 'repo.status()' at N
'fakedirstatewritetime.py' forces 'pack_dirstate()' to use
"2000-01-01 00:00" as "now", only if 'pack_dirstate()' is invoked
via 'workingctx._checklookup()'.
- invoke 'dirstate.write()' via releasing wlock at N+1 (or "not at N")
'pack_dirstate()' via releasing wlock uses actual timestamp at
runtime as "now", and it should be different from the "2000-01-01
00:00" of "f".
BTW, this patch also changes 'test-largefiles-misc.t', because adding
'dirstate.write()' makes recent dirstate changes visible to external
process.
FUJIWARA Katsunori <foozy@lares.dti.ne.jp> [Wed, 08 Jul 2015 17:01:09 +0900] rev 25752
tests: add extension to emulate invoking dirstate.write at the specific time
This extension fakes 'now' for 'parsers.pack_dirstate()' to emulate
invoking 'dirstate.write()' at the specific time, only when
'dirstate.write()' is invoked via functions below:
- 'workingctx._checklookup()' (= 'repo.status()')
- 'committablectx.markcommitted()'
This is useful to reproduce timing critical issues fixed in subsequent
patches.