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.
$ unset HGUSER
$ EMAIL="My Name <myname@example.com>"
$ export EMAIL
$ hg init test
$ cd test
$ touch asdf
$ hg add asdf
$ hg commit -m commit-1
$ hg tip
changeset: 0:53f268a58230
tag: tip
user: My Name <myname@example.com>
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit-1
$ unset EMAIL
$ echo 1234 > asdf
$ hg commit -u "foo@bar.com" -m commit-1
$ hg tip
changeset: 1:3871b2a9e9bf
tag: tip
user: foo@bar.com
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit-1
$ echo "[ui]" >> .hg/hgrc
$ echo "username = foobar <foo@bar.com>" >> .hg/hgrc
$ echo 12 > asdf
$ hg commit -m commit-1
$ hg tip
changeset: 2:8eeac6695c1c
tag: tip
user: foobar <foo@bar.com>
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit-1
$ echo 1 > asdf
$ hg commit -u "foo@bar.com" -m commit-1
$ hg tip
changeset: 3:957606a725e4
tag: tip
user: foo@bar.com
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit-1
$ echo 123 > asdf
$ echo "[ui]" > .hg/hgrc
$ echo "username = " >> .hg/hgrc
$ hg commit -m commit-1
abort: no username supplied
(use 'hg config --edit' to set your username)
[255]
# test alternate config var
$ echo 1234 > asdf
$ echo "[ui]" > .hg/hgrc
$ echo "user = Foo Bar II <foo2@bar.com>" >> .hg/hgrc
$ hg commit -m commit-1
$ hg tip
changeset: 4:6f24bfb4c617
tag: tip
user: Foo Bar II <foo2@bar.com>
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit-1
# test prompt username
$ cat > .hg/hgrc <<EOF
> [ui]
> askusername = True
> EOF
$ echo 12345 > asdf
$ hg commit --config ui.interactive=False -m ask
enter a commit username:
no username found, using '[^']*' instead (re)
$ hg rollback -q
$ hg commit --config ui.interactive=True -m ask <<EOF
> Asked User <ask@example.com>
> EOF
enter a commit username: Asked User <ask@example.com>
$ hg tip
changeset: 5:84c91d963b70
tag: tip
user: Asked User <ask@example.com>
date: Thu Jan 01 00:00:00 1970 +0000
summary: ask
# test no .hg/hgrc (uses generated non-interactive username)
$ echo space > asdf
$ rm .hg/hgrc
$ hg commit -m commit-1 2>&1
no username found, using '[^']*' instead (re)
$ echo space2 > asdf
$ hg commit -u ' ' -m commit-1
transaction abort!
rollback completed
abort: empty username!
[255]
# don't add tests here, previous test is unstable
$ cd ..