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 cvs
Test config convert.cvsps.mergefrom config setting.
(Should test similar mergeto feature, but I don't understand it yet.)
Requires builtin cvsps.
$ CVSROOT=`pwd`/cvsrepo
$ export CVSROOT
$ cvscall()
> {
> cvs -f "$@"
> }
output of 'cvs ci' varies unpredictably, so just discard it
XXX copied from test-convert-cvs-synthetic
$ cvsci()
> {
> sleep 1
> cvs -f ci "$@" > /dev/null
> }
XXX copied from test-convert-cvs-synthetic
$ cat <<EOF >> $HGRCPATH
> [extensions]
> convert =
> [convert]
> cvsps.cache = 0
> cvsps.mergefrom = \[MERGE from (\S+)\]
> EOF
create cvs repository with one project
$ cvscall -q -d "$CVSROOT" init
$ mkdir cvsrepo/proj
populate cvs repository
$ cvscall -Q co proj
$ cd proj
$ touch file1
$ cvscall -Q add file1
$ cvsci -m"add file1 on trunk"
cvs commit: Examining .
create two release branches
$ cvscall -q tag -b v1_0
T file1
$ cvscall -q tag -b v1_1
T file1
modify file1 on branch v1_0
$ cvscall -Q update -rv1_0
$ sleep 1
$ echo "change" >> file1
$ cvsci -m"add text"
cvs commit: Examining .
make unrelated change on v1_1
$ cvscall -Q update -rv1_1
$ touch unrelated
$ cvscall -Q add unrelated
$ cvsci -m"unrelated change"
cvs commit: Examining .
merge file1 to v1_1
$ cvscall -Q update -jv1_0
RCS file: $TESTTMP/cvsrepo/proj/file1,v
retrieving revision 1.1
retrieving revision 1.1.2.1
Merging differences between 1.1 and 1.1.2.1 into file1
$ cvsci -m"add text [MERGE from v1_0]"
cvs commit: Examining .
merge change to trunk
$ cvscall -Q update -A
$ cvscall -Q update -jv1_1
RCS file: $TESTTMP/cvsrepo/proj/file1,v
retrieving revision 1.1
retrieving revision 1.1.4.1
Merging differences between 1.1 and 1.1.4.1 into file1
$ cvsci -m"add text [MERGE from v1_1]"
cvs commit: Examining .
non-merged change on trunk
$ echo "foo" > file2
$ cvscall -Q add file2
$ cvsci -m"add file2 on trunk" file2
this will create rev 1.3
change on trunk to backport
$ echo "backport me" >> file1
$ cvsci -m"add other text" file1
$ cvscall log file1
RCS file: $TESTTMP/cvsrepo/proj/file1,v
Working file: file1
head: 1.3
branch:
locks: strict
access list:
symbolic names:
v1_1: 1.1.0.4
v1_0: 1.1.0.2
keyword substitution: kv
total revisions: 5; selected revisions: 5
description:
----------------------------
revision 1.3
date: * (glob)
add other text
----------------------------
revision 1.2
date: * (glob)
add text [MERGE from v1_1]
----------------------------
revision 1.1
date: * (glob)
branches: 1.1.2; 1.1.4;
add file1 on trunk
----------------------------
revision 1.1.4.1
date: * (glob)
add text [MERGE from v1_0]
----------------------------
revision 1.1.2.1
date: * (glob)
add text
=============================================================================
XXX how many ways are there to spell "trunk" with CVS?
backport trunk change to v1_1
$ cvscall -Q update -rv1_1
$ cvscall -Q update -j1.2 -j1.3 file1
RCS file: $TESTTMP/cvsrepo/proj/file1,v
retrieving revision 1.2
retrieving revision 1.3
Merging differences between 1.2 and 1.3 into file1
$ cvsci -m"add other text [MERGE from HEAD]" file1
fix bug on v1_1, merge to trunk with error
$ cvscall -Q update -rv1_1
$ echo "merge forward" >> file1
$ cvscall -Q tag unmerged
$ cvsci -m"fix file1"
cvs commit: Examining .
$ cvscall -Q update -A
$ cvscall -Q update -junmerged -jv1_1
RCS file: $TESTTMP/cvsrepo/proj/file1,v
retrieving revision 1.1.4.2
retrieving revision 1.1.4.3
Merging differences between 1.1.4.2 and 1.1.4.3 into file1
note the typo in the commit log message
$ cvsci -m"fix file1 [MERGE from v1-1]"
cvs commit: Examining .
$ cvs -Q tag -d unmerged
convert to hg
$ cd ..
$ hg convert proj proj.hg
initializing destination proj.hg repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
12 log entries
creating changesets
warning: CVS commit message references non-existent branch 'v1-1':
fix file1 [MERGE from v1-1]
10 changeset entries
sorting...
converting...
9 add file1 on trunk
8 unrelated change
7 add text
6 add text [MERGE from v1_0]
5 add text [MERGE from v1_1]
4 add file2 on trunk
3 add other text
2 add other text [MERGE from HEAD]
1 fix file1
0 fix file1 [MERGE from v1-1]
complete log
$ template="{rev}: '{branches}' {desc}\n"
$ hg -R proj.hg log --template="$template"
9: '' fix file1 [MERGE from v1-1]
8: 'v1_1' fix file1
7: 'v1_1' add other text [MERGE from HEAD]
6: '' add other text
5: '' add file2 on trunk
4: '' add text [MERGE from v1_1]
3: 'v1_1' add text [MERGE from v1_0]
2: 'v1_0' add text
1: 'v1_1' unrelated change
0: '' add file1 on trunk
graphical log
$ hg -R proj.hg log -G --template="$template"
o 9: '' fix file1 [MERGE from v1-1]
|
| o 8: 'v1_1' fix file1
| |
| o 7: 'v1_1' add other text [MERGE from HEAD]
|/|
o | 6: '' add other text
| |
o | 5: '' add file2 on trunk
| |
o | 4: '' add text [MERGE from v1_1]
|\|
| o 3: 'v1_1' add text [MERGE from v1_0]
| |\
+---o 2: 'v1_0' add text
| |
| o 1: 'v1_1' unrelated change
|/
o 0: '' add file1 on trunk