##// END OF EJS Templates
lock: fix race in lock-breaking code...
lock: fix race in lock-breaking code With low frequency, I see hg pulls fail with output like: abort: no such file or directory: .hg/store/lock I think what happens is, in lock.py, in: def _testlock(self, locker): if not self._lockshouldbebroken(locker): return locker # if locker dead, break lock. must do this with another lock # held, or can race and break valid lock. try: with lock(self.vfs, self.f + b'.break', timeout=0): self.vfs.unlink(self.f) except error.LockError: return locker if a lock is breakable on disk, and two hg processes concurrently get to the "if locker dead" comment, a possible interleaving is: process1 finishes executing the function and then process2 finishes executing the function. If that happens, process2 will either get ENOENT in self.vfs.unlink (resulting in the spurious failure above), or break a valid lock and potentially cause repository corruption. The fix is simple enough: make sure the lock is breakable _inside_ the critical section, because only then can we know that no other process can invalidate our knowledge on the lock on disk. I don't think there are tests for this. I've tested this manually with: diff --git a/mercurial/lock.py b/mercurial/lock.py --- a/mercurial/lock.py +++ b/mercurial/lock.py @@ -351,6 +351,8 @@ class lock(object): if not self._lockshouldbebroken(locker): return locker + import random + time.sleep(1. + random.random()) # if locker dead, break lock. must do this with another lock # held, or can race and break valid lock. try: @@ -358,6 +360,7 @@ class lock(object): self.vfs.unlink(self.f) except error.LockError: return locker + time.sleep(1) def testlock(self): """return id of locker if lock is valid, else None. and I see this change of behavior before/after this commit: $ $hg init repo $ cd repo $ ln -s $HOSTNAME/effffffc:987654321 .hg/wlock $ touch a $ $hg commit -Am_ & $hg commit -Am _; wait -abort: No such file or directory: '/tmp/repo/.hg/wlock' adding a +warning: ignoring unknown working parent 679a8959a8ca! +nothing changed Differential Revision: https://phab.mercurial-scm.org/D7199

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i18n.py
115 lines | 3.8 KiB | text/x-python | PythonLexer
# i18n.py - internationalization support for mercurial
#
# Copyright 2005, 2006 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
import gettext as gettextmod
import locale
import os
import sys
from .pycompat import getattr
from .utils import resourceutil
from . import (
encoding,
pycompat,
)
# modelled after templater.templatepath:
if getattr(sys, 'frozen', None) is not None:
module = pycompat.sysexecutable
else:
module = pycompat.fsencode(__file__)
_languages = None
if (
pycompat.iswindows
and b'LANGUAGE' not in encoding.environ
and b'LC_ALL' not in encoding.environ
and b'LC_MESSAGES' not in encoding.environ
and b'LANG' not in encoding.environ
):
# Try to detect UI language by "User Interface Language Management" API
# if no locale variables are set. Note that locale.getdefaultlocale()
# uses GetLocaleInfo(), which may be different from UI language.
# (See http://msdn.microsoft.com/en-us/library/dd374098(v=VS.85).aspx )
try:
import ctypes
langid = ctypes.windll.kernel32.GetUserDefaultUILanguage()
_languages = [locale.windows_locale[langid]]
except (ImportError, AttributeError, KeyError):
# ctypes not found or unknown langid
pass
datapath = pycompat.fsdecode(resourceutil.datapath)
localedir = os.path.join(datapath, 'locale')
t = gettextmod.translation('hg', localedir, _languages, fallback=True)
try:
_ugettext = t.ugettext
except AttributeError:
_ugettext = t.gettext
_msgcache = {} # encoding: {message: translation}
def gettext(message):
"""Translate message.
The message is looked up in the catalog to get a Unicode string,
which is encoded in the local encoding before being returned.
Important: message is restricted to characters in the encoding
given by sys.getdefaultencoding() which is most likely 'ascii'.
"""
# If message is None, t.ugettext will return u'None' as the
# translation whereas our callers expect us to return None.
if message is None or not _ugettext:
return message
cache = _msgcache.setdefault(encoding.encoding, {})
if message not in cache:
if type(message) is pycompat.unicode:
# goofy unicode docstrings in test
paragraphs = message.split(u'\n\n')
else:
# should be ascii, but we have unicode docstrings in test, which
# are converted to utf-8 bytes on Python 3.
paragraphs = [p.decode("utf-8") for p in message.split(b'\n\n')]
# Be careful not to translate the empty string -- it holds the
# meta data of the .po file.
u = u'\n\n'.join([p and _ugettext(p) or u'' for p in paragraphs])
try:
# encoding.tolocal cannot be used since it will first try to
# decode the Unicode string. Calling u.decode(enc) really
# means u.encode(sys.getdefaultencoding()).decode(enc). Since
# the Python encoding defaults to 'ascii', this fails if the
# translated string use non-ASCII characters.
encodingstr = pycompat.sysstr(encoding.encoding)
cache[message] = u.encode(encodingstr, "replace")
except LookupError:
# An unknown encoding results in a LookupError.
cache[message] = message
return cache[message]
def _plain():
if (
b'HGPLAIN' not in encoding.environ
and b'HGPLAINEXCEPT' not in encoding.environ
):
return False
exceptions = encoding.environ.get(b'HGPLAINEXCEPT', b'').strip().split(b',')
return b'i18n' not in exceptions
if _plain():
_ = lambda message: message
else:
_ = gettext