commandserver: add new forking server implemented without using SocketServer
SocketServer.ForkingMixIn of Python 2.x has a couple of issues, such as:
- race condition that leads to 100% CPU usage (Python 2.6)
https://bugs.python.org/
issue21491
- can't wait for children belonging to different process groups (Python 2.6)
- leaves at least one zombie process (Python 2.6, 2.7)
https://bugs.python.org/
issue11109
The first two are critical because we do setpgid(0, 0) in child process to
isolate terminal signals. The last one isn't, but ForkingMixIn seems to be
doing silly. So there are two choices:
a) backport and maintain SocketServer until we can drop support for Python 2.x
b) replace SocketServer by simpler one and eliminate glue codes
I chose (b) because it's great time for getting rid of utterly complicated
SocketServer stuff, and preparing for future move towards prefork service.
New unixforkingservice is implemented loosely based on chg
531f8ef64be6. It
is monolithic but much simpler than SocketServer. unixservicehandler provides
customizing points for chg, and it will be shared with future prefork service.
Old unixservice class is still used by chgserver. It will be removed later.
Thanks to Jun Wu for investigating these issues.
Test the EOL hook
$ hg init main
$ cat > main/.hg/hgrc <<EOF
> [hooks]
> pretxnchangegroup = python:hgext.eol.hook
> EOF
$ hg clone main fork
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd fork
Create repo
$ cat > .hgeol <<EOF
> [patterns]
> mixed.txt = BIN
> crlf.txt = CRLF
> **.txt = native
> EOF
$ hg add .hgeol
$ hg commit -m 'Commit .hgeol'
$ printf "first\nsecond\nthird\n" > a.txt
$ hg add a.txt
$ hg commit -m 'LF a.txt'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
$ printf "first\r\nsecond\r\nthird\n" > a.txt
$ hg commit -m 'CRLF a.txt'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
error: pretxnchangegroup hook failed: end-of-line check failed:
a.txt in a8ee6548cd86 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
a.txt in a8ee6548cd86 should not have CRLF line endings
[255]
$ printf "first\nsecond\nthird\n" > a.txt
$ hg commit -m 'LF a.txt (fixed)'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
$ printf "first\nsecond\nthird\n" > crlf.txt
$ hg add crlf.txt
$ hg commit -m 'LF crlf.txt'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
error: pretxnchangegroup hook failed: end-of-line check failed:
crlf.txt in 004ba2132725 should not have LF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
crlf.txt in 004ba2132725 should not have LF line endings
[255]
$ printf "first\r\nsecond\r\nthird\r\n" > crlf.txt
$ hg commit -m 'CRLF crlf.txt (fixed)'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
$ printf "first\r\nsecond" > b.txt
$ hg add b.txt
$ hg commit -m 'CRLF b.txt'
$ hg push ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
[255]
$ hg up -r -2
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ printf "some\nother\nfile" > c.txt
$ hg add c.txt
$ hg commit -m "LF c.txt, b.txt doesn't exist here"
created new head
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files (+1 heads)
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
[255]
Test checkheadshook alias
$ cat > ../main/.hg/hgrc <<EOF
> [hooks]
> pretxnchangegroup = python:hgext.eol.checkheadshook
> EOF
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files (+1 heads)
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
[255]
We can fix the head and push again
$ hg up 6
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ printf "first\nsecond" > b.txt
$ hg ci -m "remove CRLF from b.txt"
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 2 files (+1 heads)
$ hg -R ../main rollback
repository tip rolled back to revision 5 (undo push)
Test it still fails with checkallhook
$ cat > ../main/.hg/hgrc <<EOF
> [hooks]
> pretxnchangegroup = python:hgext.eol.checkallhook
> EOF
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 2 files (+1 heads)
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
[255]
But we can push the clean head
$ hg push -r7 -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
Test multiple files/revisions output
$ printf "another\r\nbad\r\none" > d.txt
$ hg add d.txt
$ hg ci -m "add d.txt"
$ hg push -f ../main
pushing to ../main
searching for changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 2 files (+1 heads)
error: pretxnchangegroup hook failed: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
d.txt in a7040e68714f should not have CRLF line endings
transaction abort!
rollback completed
abort: end-of-line check failed:
b.txt in fbcf9b1025f5 should not have CRLF line endings
d.txt in a7040e68714f should not have CRLF line endings
[255]
$ cd ..