##// END OF EJS Templates
hg: obtain lock when creating share from pooled repo (issue5104)...
hg: obtain lock when creating share from pooled repo (issue5104) There are race conditions between clients performing a shared clone to pooled storage: 1) Clients race to create the new shared repo in the pool directory 2) 1 client is seeding the repo in the pool directory and another goes to share it before it is fully cloned We prevent these race conditions by obtaining a lock in the pool directory that is derived from the name of the repo we will be accessing. To test this, a simple generic "lockdelay" extension has been added. The extension inserts an optional, configurable delay before or after lock acquisition. In the test, we delay 2 seconds after lock acquisition in the first process and 1 second before lock acquisition in the 2nd process. This means the first process has 1s to obtain the lock. There is a race condition here. If we encounter it in the wild, we could change the dummy extension to wait on the lock file to appear instead of relying on timing. But that's more complicated. Let's see what happens first.

File last commit:

r27769:40bd01be default
r28289:d493d647 3.7.2 stable
Show More
localstore.py
70 lines | 2.3 KiB | text/x-python | PythonLexer
# Copyright 2009-2010 Gregory P. Ward
# Copyright 2009-2010 Intelerad Medical Systems Incorporated
# Copyright 2010-2011 Fog Creek Software
# Copyright 2010-2011 Unity Technologies
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''store class for local filesystem'''
from mercurial.i18n import _
import lfutil
import basestore
class localstore(basestore.basestore):
'''localstore first attempts to grab files out of the store in the remote
Mercurial repository. Failing that, it attempts to grab the files from
the user cache.'''
def __init__(self, ui, repo, remote):
self.remote = remote.local()
super(localstore, self).__init__(ui, repo, self.remote.url())
def put(self, source, hash):
if lfutil.instore(self.remote, hash):
return
lfutil.link(source, lfutil.storepath(self.remote, hash))
def exists(self, hashes):
retval = {}
for hash in hashes:
retval[hash] = lfutil.instore(self.remote, hash)
return retval
def _getfile(self, tmpfile, filename, hash):
path = lfutil.findfile(self.remote, hash)
if not path:
raise basestore.StoreError(filename, hash, self.url,
_("can't get file locally"))
with open(path, 'rb') as fd:
return lfutil.copyandhash(fd, tmpfile)
def _verifyfile(self, cctx, cset, contents, standin, verified):
filename = lfutil.splitstandin(standin)
if not filename:
return False
fctx = cctx[standin]
key = (filename, fctx.filenode())
if key in verified:
return False
expecthash = fctx.data()[0:40]
storepath, exists = lfutil.findstorepath(self.remote, expecthash)
verified.add(key)
if not exists:
self.ui.warn(
_('changeset %s: %s references missing %s\n')
% (cset, filename, storepath))
return True # failed
if contents:
actualhash = lfutil.hashfile(storepath)
if actualhash != expecthash:
self.ui.warn(
_('changeset %s: %s references corrupted %s\n')
% (cset, filename, storepath))
return True # failed
return False