##// END OF EJS Templates
commands: make commit acquire locks before processing (issue4368)...
commands: make commit acquire locks before processing (issue4368) Before this patch, "hg commit" (process A) executes steps below: 1. get current branch heads via 'repo.branchheads()' - cache 'repo.changelog' 2. invoke 'repo.commit()' 3. acquire wlock - invalidate 'repo.dirstate' 4. access 'repo.dirstate' - re-read '.hg/dirstate' - check validity of parent revisions with 'repo.changelog' 5. invoke 'repo.commitctx()' 6. acquire store lock (slock) - invalidate 'repo.changelog' 7. do committing 8. release slock 9. release wlock 10. check new branch head (via 'cmdutil.commitstatus()') If acquisition of wlock at (3) above waits for another "hg commit" (process B) or so running parallelly to release wlock, process A causes creating orphan revision, because: - '.hg/dirstate' refers the revision, which is newly added by process B, as its parent - but already cached 'repo.changelog' doesn't contain such revision - therefore, validating parents of '.hg/dirstate' at (4) above replaces such revision with 'nullid' Then, process A creates "orphan" revision, of which parent is "null" revision. In addition to it, "created new head" may be shown at the end of process A unintentionally, if store is updated parallelly, because both getting branch heads (1) and checking new branch head (10) are executed outside slock scope. To avoid this issue, this patch makes "hg commit" acquire wlock and slock before processing. This patch resolves the issue between "hg commit" processes, but not one between "hg commit" and other commands. Subsequent patches resolve the latter. Even after this patch, there are still corner case problems below: - filecache may overlook changes of '.hg/dirstate', and it causes similar issue (see below for detail) https://bz.mercurial-scm.org/show_bug.cgi?id=4368#c10 - 3rd party extension may cause similar issue, if it directly uses 'repo.commit()' without acquisition of wlock and slock This can be fixed by acquisition of slock at the beginning of 'repo.commit()', but it seems suitable for "default" branch In fact, acquisition of slock itself is already introduced at "default" branch by 4414d500604f, but acquisition is not at the beginning of 'repo.commit()'. This patch also changes some tests: - test-fncache.t needs this tricky wrapping, to release (= forced failure of) wlock certainly - order of "hg commit" output is changed by widening scope of locks, because some hooks are fired after releasing wlock

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sshserver.py
134 lines | 3.6 KiB | text/x-python | PythonLexer
# sshserver.py - ssh protocol server support for mercurial
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import os
import sys
from . import (
error,
hook,
util,
wireproto,
)
class sshserver(wireproto.abstractserverproto):
def __init__(self, ui, repo):
self.ui = ui
self.repo = repo
self.lock = None
self.fin = ui.fin
self.fout = ui.fout
hook.redirect(True)
ui.fout = repo.ui.fout = ui.ferr
# Prevent insertion/deletion of CRs
util.setbinary(self.fin)
util.setbinary(self.fout)
def getargs(self, args):
data = {}
keys = args.split()
for n in xrange(len(keys)):
argline = self.fin.readline()[:-1]
arg, l = argline.split()
if arg not in keys:
raise error.Abort("unexpected parameter %r" % arg)
if arg == '*':
star = {}
for k in xrange(int(l)):
argline = self.fin.readline()[:-1]
arg, l = argline.split()
val = self.fin.read(int(l))
star[arg] = val
data['*'] = star
else:
val = self.fin.read(int(l))
data[arg] = val
return [data[k] for k in keys]
def getarg(self, name):
return self.getargs(name)[0]
def getfile(self, fpout):
self.sendresponse('')
count = int(self.fin.readline())
while count:
fpout.write(self.fin.read(count))
count = int(self.fin.readline())
def redirect(self):
pass
def groupchunks(self, changegroup):
while True:
d = changegroup.read(4096)
if not d:
break
yield d
def sendresponse(self, v):
self.fout.write("%d\n" % len(v))
self.fout.write(v)
self.fout.flush()
def sendstream(self, source):
write = self.fout.write
for chunk in source.gen:
write(chunk)
self.fout.flush()
def sendpushresponse(self, rsp):
self.sendresponse('')
self.sendresponse(str(rsp.res))
def sendpusherror(self, rsp):
self.sendresponse(rsp.res)
def sendooberror(self, rsp):
self.ui.ferr.write('%s\n-\n' % rsp.message)
self.ui.ferr.flush()
self.fout.write('\n')
self.fout.flush()
def serve_forever(self):
try:
while self.serve_one():
pass
finally:
if self.lock is not None:
self.lock.release()
sys.exit(0)
handlers = {
str: sendresponse,
wireproto.streamres: sendstream,
wireproto.pushres: sendpushresponse,
wireproto.pusherr: sendpusherror,
wireproto.ooberror: sendooberror,
}
def serve_one(self):
cmd = self.fin.readline()[:-1]
if cmd and cmd in wireproto.commands:
rsp = wireproto.dispatch(self.repo, self, cmd)
self.handlers[rsp.__class__](self, rsp)
elif cmd:
impl = getattr(self, 'do_' + cmd, None)
if impl:
r = impl()
if r is not None:
self.sendresponse(r)
else: self.sendresponse("")
return cmd != ''
def _client(self):
client = os.environ.get('SSH_CLIENT', '').split(' ', 1)[0]
return 'remote:ssh:' + client