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.
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
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 (glob)
# path aliases to other clones of this repo in URLs or filesystem paths
# (see "hg help config.paths" for more info)
#
# default-push = ssh://jdoe@example.net/hg/jdoes-fork
# my-fork = ssh://jdoe@example.net/hg/jdoes-fork
# my-clone = /home/jdoe/jdoes-clone
[ui]
# name and email (local to this repository, optional), e.g.
# username = Jane Doe <jdoe@example.com>
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 ..