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.
#require test-repo slow osx osxpackaging
$ . "$TESTDIR/helpers-testrepo.sh"
$ OUTPUTDIR=`pwd`
$ export OUTPUTDIR
$ KEEPMPKG=yes
$ export KEEPMPKG
$ cd "$TESTDIR"/..
$ rm -rf dist
$ make osx > $OUTPUTDIR/build.log 2>&1
$ cd $OUTPUTDIR
$ ls -d *.pkg
Mercurial-*-macosx10.*.pkg (glob)
$ xar -xf Mercurial*.pkg
Gather list of all installed files:
$ lsbom mercurial.pkg/Bom > boms.txt
Spot-check some randomly selected files:
$ grep bdiff boms.txt | cut -d ' ' -f 1,2,3
./Library/Python/2.7/site-packages/mercurial/bdiff.so 100755 0/0
./Library/Python/2.7/site-packages/mercurial/pure/bdiff.py 100644 0/0
./Library/Python/2.7/site-packages/mercurial/pure/bdiff.pyc 100644 0/0
./Library/Python/2.7/site-packages/mercurial/pure/bdiff.pyo 100644 0/0
$ egrep 'man[15]' boms.txt | cut -d ' ' -f 1,2,3
./usr/local/share/man/man1 40755 0/0
./usr/local/share/man/man1/hg.1 100644 0/0
./usr/local/share/man/man5 40755 0/0
./usr/local/share/man/man5/hgignore.5 100644 0/0
./usr/local/share/man/man5/hgrc.5 100644 0/0
$ grep bser boms.txt | cut -d ' ' -f 1,2,3
./Library/Python/2.7/site-packages/hgext/fsmonitor/pywatchman/bser.so 100755 0/0
./Library/Python/2.7/site-packages/hgext/fsmonitor/pywatchman/pybser.py 100644 0/0
./Library/Python/2.7/site-packages/hgext/fsmonitor/pywatchman/pybser.pyc 100644 0/0
./Library/Python/2.7/site-packages/hgext/fsmonitor/pywatchman/pybser.pyo 100644 0/0
$ grep localrepo boms.txt | cut -d ' ' -f 1,2,3
./Library/Python/2.7/site-packages/mercurial/localrepo.py 100644 0/0
./Library/Python/2.7/site-packages/mercurial/localrepo.pyc 100644 0/0
./Library/Python/2.7/site-packages/mercurial/localrepo.pyo 100644 0/0
$ grep '/hg ' boms.txt | cut -d ' ' -f 1,2,3
./usr/local/bin/hg 100755 0/0
Make sure the built binary uses the system Python interpreter
$ bsdtar xf mercurial.pkg/Payload usr/local/bin
Use a glob to find this to avoid check-code whining about a fixed path.
$ head -n 1 usr/local/b?n/hg
#!/System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python
Note that we're not currently installing any /etc/mercurial stuff,
including merge-tool configurations.