##// 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.

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r25969:7b200566 default
r28289:d493d647 3.7.2 stable
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pushkey.py
61 lines | 1.7 KiB | text/x-python | PythonLexer
# pushkey.py - dispatching for pushing and pulling keys
#
# Copyright 2010 Matt Mackall <mpm@selenic.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
from . import (
bookmarks,
encoding,
obsolete,
phases,
)
def _nslist(repo):
n = {}
for k in _namespaces:
n[k] = ""
if not obsolete.isenabled(repo, obsolete.exchangeopt):
n.pop('obsolete')
return n
_namespaces = {"namespaces": (lambda *x: False, _nslist),
"bookmarks": (bookmarks.pushbookmark, bookmarks.listbookmarks),
"phases": (phases.pushphase, phases.listphases),
"obsolete": (obsolete.pushmarker, obsolete.listmarkers),
}
def register(namespace, pushkey, listkeys):
_namespaces[namespace] = (pushkey, listkeys)
def _get(namespace):
return _namespaces.get(namespace, (lambda *x: False, lambda *x: {}))
def push(repo, namespace, key, old, new):
'''should succeed iff value was old'''
pk = _get(namespace)[0]
return pk(repo, key, old, new)
def list(repo, namespace):
'''return a dict'''
lk = _get(namespace)[1]
return lk(repo)
encode = encoding.fromlocal
decode = encoding.tolocal
def encodekeys(keys):
"""encode the content of a pushkey namespace for exchange over the wire"""
return '\n'.join(['%s\t%s' % (encode(k), encode(v)) for k, v in keys])
def decodekeys(data):
"""decode the content of a pushkey namespace from exchange over the wire"""
result = {}
for l in data.splitlines():
k, v = l.split('\t')
result[decode(k)] = decode(v)
return result