lock: block signal interrupt while making a lock file
On Windows where symlink isn't supported, util.makelock() could leave an empty
file if interrupted immediately after os.open(). This empty lock never dies
as it has no process id recorded.
ld = os.open(pathname, os.O_CREAT | os.O_WRONLY | os.O_EXCL)
# an interrupt may occur here
os.write(ld, info)
os.close(ld)
This was a long-standing bug of TortoiseHg which runs a command-server and
kills it by CTRL_C_EVENT, reported by random Windows users.
https://bitbucket.org/tortoisehg/thg/issues/4873/#comment-
43591129
At first, I tried to fix makelock() to clean up a stale lock file, which
turned out to be hard because any instructions may be interrupted by a
signal.
ld = None
try:
# CALL_FUNCTION # os.open(...)
# an interrupt may occur here
# STORE_FAST # ld = ...
ld = os.open(pathname, os.O_CREAT | os.O_WRONLY | os.O_EXCL)
os.write(ld, info)
...
return True
except:
if ld:
...
os.unlink(pathname)
return False
So I decided to block signals by temporarily replacing the signal handlers
so makelcok() and held = 1 will never be interrupted.
Many thanks to Fernando Najera for investigating the issue.
This test tries to exercise the ssh functionality with a dummy script
#testcases sshv1 sshv2
#if sshv2
$ cat >> $HGRCPATH << EOF
> [experimental]
> sshpeer.advertise-v2 = true
> sshserver.support-v2 = true
> EOF
#endif
creating 'remote' repo
$ hg init remote
$ cd remote
$ hg unbundle "$TESTDIR/bundles/remote.hg"
adding changesets
adding manifests
adding file changes
added 9 changesets with 7 changes to 4 files (+1 heads)
new changesets bfaf4b5cbf01:916f1afdef90
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg up tip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ..
clone remote via stream
$ for i in 0 1 2 3 4 5 6 7 8; do
> hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" --stream -r "$i" ssh://user@dummy/remote test-"$i"
> if cd test-"$i"; then
> hg verify
> cd ..
> fi
> done
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets bfaf4b5cbf01
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets bfaf4b5cbf01:21f32785131f
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
new changesets bfaf4b5cbf01:4ce51a113780
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 3 changesets, 3 total revisions
adding changesets
adding manifests
adding file changes
added 4 changesets with 4 changes to 1 files
new changesets bfaf4b5cbf01:93ee6ab32777
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 4 changesets, 4 total revisions
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets bfaf4b5cbf01:c70afb1ee985
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
new changesets bfaf4b5cbf01:f03ae5a9b979
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 3 changesets, 3 total revisions
adding changesets
adding manifests
adding file changes
added 4 changesets with 5 changes to 2 files
new changesets bfaf4b5cbf01:095cb14b1b4d
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 4 changesets, 5 total revisions
adding changesets
adding manifests
adding file changes
added 5 changesets with 6 changes to 3 files
new changesets bfaf4b5cbf01:faa2e4234c7a
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
3 files, 5 changesets, 6 total revisions
adding changesets
adding manifests
adding file changes
added 5 changesets with 5 changes to 2 files
new changesets bfaf4b5cbf01:916f1afdef90
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 5 changesets, 5 total revisions
$ cd test-8
$ hg pull ../test-7
pulling from ../test-7
searching for changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 2 changes to 3 files (+1 heads)
new changesets c70afb1ee985:faa2e4234c7a
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
4 files, 9 changesets, 7 total revisions
$ cd ..
$ cd test-1
$ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" -r 4 ssh://user@dummy/remote
pulling from ssh://user@dummy/remote
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files (+1 heads)
new changesets c70afb1ee985
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 3 changesets, 2 total revisions
$ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote
pulling from ssh://user@dummy/remote
searching for changes
adding changesets
adding manifests
adding file changes
added 6 changesets with 5 changes to 4 files
new changesets 4ce51a113780:916f1afdef90
(run 'hg update' to get a working copy)
$ cd ..
$ cd test-2
$ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" -r 5 ssh://user@dummy/remote
pulling from ssh://user@dummy/remote
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 0 changes to 0 files (+1 heads)
new changesets c70afb1ee985:f03ae5a9b979
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 5 changesets, 3 total revisions
$ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote
pulling from ssh://user@dummy/remote
searching for changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 4 changes to 4 files
new changesets 93ee6ab32777:916f1afdef90
(run 'hg update' to get a working copy)
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
4 files, 9 changesets, 7 total revisions
$ cd ..