hg: obtain lock when creating share from pooled repo (issue5104)
There are race conditions between clients performing a shared clone
to pooled storage:
1) Clients race to create the new shared repo in the pool directory
2) 1 client is seeding the repo in the pool directory and another goes
to share it before it is fully cloned
We prevent these race conditions by obtaining a lock in the pool
directory that is derived from the name of the repo we will be
accessing.
To test this, a simple generic "lockdelay" extension has been added.
The extension inserts an optional, configurable delay before or after
lock acquisition. In the test, we delay 2 seconds after lock acquisition
in the first process and 1 second before lock acquisition in the 2nd
process. This means the first process has 1s to obtain the lock. There
is a race condition here. If we encounter it in the wild, we could
change the dummy extension to wait on the lock file to appear instead
of relying on timing. But that's more complicated. Let's see what
happens first.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}: '{desc}' {branches}\n"
> EOF
$ hg init a
$ cd a
$ hg unbundle "$TESTDIR/bundles/rebase.hg"
adding changesets
adding manifests
adding file changes
added 8 changesets with 7 changes to 7 files (+2 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg up tip
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo I > I
$ hg ci -AmI
adding I
$ hg tglog
@ 8: 'I'
|
o 7: 'H'
|
| o 6: 'G'
|/|
o | 5: 'F'
| |
| o 4: 'E'
|/
| o 3: 'D'
| |
| o 2: 'C'
| |
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
These fail:
$ hg clone -q -u . a a1
$ cd a1
$ hg rebase -s 8 -d 7
nothing to rebase
[1]
$ hg rebase --continue --abort
abort: cannot use both abort and continue
[255]
$ hg rebase --continue --collapse
abort: cannot use collapse with continue or abort
[255]
$ hg rebase --continue --dest 4
abort: abort and continue do not allow specifying revisions
[255]
$ hg rebase --base 5 --source 4
abort: cannot specify both a source and a base
[255]
$ hg rebase --rev 5 --source 4
abort: cannot specify both a revision and a source
[255]
$ hg rebase --base 5 --rev 4
abort: cannot specify both a revision and a base
[255]
$ hg rebase --rev '1 & !1'
empty "rev" revision set - nothing to rebase
[1]
$ hg rebase --source '1 & !1'
empty "source" revision set - nothing to rebase
[1]
$ hg rebase --base '1 & !1'
empty "base" revision set - can't compute rebase set
[1]
$ hg rebase
nothing to rebase - working directory parent is also destination
[1]
$ hg rebase -b.
nothing to rebase - e7ec4e813ba6 is both "base" and destination
[1]
$ hg up -q 7
$ hg rebase --traceback
nothing to rebase - working directory parent is already an ancestor of destination e7ec4e813ba6
[1]
$ hg rebase -b.
nothing to rebase - "base" 02de42196ebe is already an ancestor of destination e7ec4e813ba6
[1]
$ hg rebase --dest '1 & !1'
abort: empty revision set
[255]
These work:
Rebase with no arguments (from 3 onto 8):
$ hg up -q -C 3
$ hg rebase
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a1/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
@ 8: 'D'
|
o 7: 'C'
|
o 6: 'B'
|
o 5: 'I'
|
o 4: 'H'
|
| o 3: 'G'
|/|
o | 2: 'F'
| |
| o 1: 'E'
|/
o 0: 'A'
Try to rollback after a rebase (fail):
$ hg rollback
no rollback information available
[1]
$ cd ..
Rebase with base == '.' => same as no arguments (from 3 onto 8):
$ hg clone -q -u 3 a a2
$ cd a2
$ hg rebase --base .
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a2/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
@ 8: 'D'
|
o 7: 'C'
|
o 6: 'B'
|
o 5: 'I'
|
o 4: 'H'
|
| o 3: 'G'
|/|
o | 2: 'F'
| |
| o 1: 'E'
|/
o 0: 'A'
$ cd ..
Rebase with dest == branch(.) => same as no arguments (from 3 onto 8):
$ hg clone -q -u 3 a a3
$ cd a3
$ hg rebase --dest 'branch(.)'
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a3/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
@ 8: 'D'
|
o 7: 'C'
|
o 6: 'B'
|
o 5: 'I'
|
o 4: 'H'
|
| o 3: 'G'
|/|
o | 2: 'F'
| |
| o 1: 'E'
|/
o 0: 'A'
$ cd ..
Specify only source (from 2 onto 8):
$ hg clone -q -u . a a4
$ cd a4
$ hg rebase --source 'desc("C")'
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a4/.hg/strip-backup/5fddd98957c8-f9244fa1-backup.hg (glob)
$ hg tglog
o 8: 'D'
|
o 7: 'C'
|
@ 6: 'I'
|
o 5: 'H'
|
| o 4: 'G'
|/|
o | 3: 'F'
| |
| o 2: 'E'
|/
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Specify only dest (from 3 onto 6):
$ hg clone -q -u 3 a a5
$ cd a5
$ hg rebase --dest 6
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a5/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
@ 8: 'D'
|
o 7: 'C'
|
o 6: 'B'
|
| o 5: 'I'
| |
| o 4: 'H'
| |
o | 3: 'G'
|\|
| o 2: 'F'
| |
o | 1: 'E'
|/
o 0: 'A'
$ cd ..
Specify only base (from 1 onto 8):
$ hg clone -q -u . a a6
$ cd a6
$ hg rebase --base 'desc("D")'
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a6/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
o 8: 'D'
|
o 7: 'C'
|
o 6: 'B'
|
@ 5: 'I'
|
o 4: 'H'
|
| o 3: 'G'
|/|
o | 2: 'F'
| |
| o 1: 'E'
|/
o 0: 'A'
$ cd ..
Specify source and dest (from 2 onto 7):
$ hg clone -q -u . a a7
$ cd a7
$ hg rebase --source 2 --dest 7
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a7/.hg/strip-backup/5fddd98957c8-f9244fa1-backup.hg (glob)
$ hg tglog
o 8: 'D'
|
o 7: 'C'
|
| @ 6: 'I'
|/
o 5: 'H'
|
| o 4: 'G'
|/|
o | 3: 'F'
| |
| o 2: 'E'
|/
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Specify base and dest (from 1 onto 7):
$ hg clone -q -u . a a8
$ cd a8
$ hg rebase --base 3 --dest 7
rebasing 1:42ccdea3bb16 "B"
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a8/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)
$ hg tglog
o 8: 'D'
|
o 7: 'C'
|
o 6: 'B'
|
| @ 5: 'I'
|/
o 4: 'H'
|
| o 3: 'G'
|/|
o | 2: 'F'
| |
| o 1: 'E'
|/
o 0: 'A'
$ cd ..
Specify only revs (from 2 onto 8)
$ hg clone -q -u . a a9
$ cd a9
$ hg rebase --rev 'desc("C")::'
rebasing 2:5fddd98957c8 "C"
rebasing 3:32af7686d403 "D"
saved backup bundle to $TESTTMP/a9/.hg/strip-backup/5fddd98957c8-f9244fa1-backup.hg (glob)
$ hg tglog
o 8: 'D'
|
o 7: 'C'
|
@ 6: 'I'
|
o 5: 'H'
|
| o 4: 'G'
|/|
o | 3: 'F'
| |
| o 2: 'E'
|/
| o 1: 'B'
|/
o 0: 'A'
$ cd ..
Rebasing both a single revision and a merge in one command
$ hg clone -q -u . a aX
$ cd aX
$ hg rebase -r 3 -r 6
rebasing 3:32af7686d403 "D"
rebasing 6:eea13746799a "G"
saved backup bundle to $TESTTMP/aX/.hg/strip-backup/eea13746799a-ad273fd6-backup.hg (glob)
$ cd ..
Test --tool parameter:
$ hg init b
$ cd b
$ echo c1 > c1
$ hg ci -Am c1
adding c1
$ echo c2 > c2
$ hg ci -Am c2
adding c2
$ hg up -q 0
$ echo c2b > c2
$ hg ci -Am c2b
adding c2
created new head
$ cd ..
$ hg clone -q -u . b b1
$ cd b1
$ hg rebase -s 2 -d 1 --tool internal:local
rebasing 2:e4e3f3546619 "c2b" (tip)
note: rebase of 2:e4e3f3546619 created no changes to commit
saved backup bundle to $TESTTMP/b1/.hg/strip-backup/e4e3f3546619-b0841178-backup.hg (glob)
$ hg cat c2
c2
$ cd ..
$ hg clone -q -u . b b2
$ cd b2
$ hg rebase -s 2 -d 1 --tool internal:other
rebasing 2:e4e3f3546619 "c2b" (tip)
saved backup bundle to $TESTTMP/b2/.hg/strip-backup/e4e3f3546619-b0841178-backup.hg (glob)
$ hg cat c2
c2b
$ cd ..
$ hg clone -q -u . b b3
$ cd b3
$ hg rebase -s 2 -d 1 --tool internal:fail
rebasing 2:e4e3f3546619 "c2b" (tip)
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
$ hg summary
parent: 1:56daeba07f4b
c2
parent: 2:e4e3f3546619 tip
c2b
branch: default
commit: 1 modified, 1 unresolved (merge)
update: (current)
phases: 3 draft
rebase: 0 rebased, 1 remaining (rebase --continue)
$ hg resolve -l
U c2
$ hg resolve -m c2
(no more unresolved files)
continue: hg rebase --continue
$ hg rebase -c --tool internal:fail
rebasing 2:e4e3f3546619 "c2b" (tip)
note: rebase of 2:e4e3f3546619 created no changes to commit
saved backup bundle to $TESTTMP/b3/.hg/strip-backup/e4e3f3546619-b0841178-backup.hg (glob)
$ hg rebase -i
abort: interactive history editing is supported by the 'histedit' extension (see "hg --config extensions.histedit= help -e histedit")
[255]
$ hg rebase --interactive
abort: interactive history editing is supported by the 'histedit' extension (see "hg --config extensions.histedit= help -e histedit")
[255]
$ cd ..
No common ancestor
$ hg init separaterepo
$ cd separaterepo
$ touch a
$ hg commit -Aqm a
$ hg up -q null
$ touch b
$ hg commit -Aqm b
$ hg rebase -d 0
nothing to rebase from d7486e00c6f1 to 3903775176ed
[1]
$ cd ..