Mercurial > hg
view mercurial/policy.py @ 30921:1f151a33af8e
lock: include Linux pid namespace identifier in prefix
Previously, the lock only contains a hostname as an attempt to detect pid
namespace difference. However, that's not enough on modern Linux - a single
hostname could have different pid namespaces.
That means if people run hg inside different PID namespaces with a same UTS
namespae, the lock would be broken - an hg proccess in pid namespace A will
think the lock having a "random" pid in pid namespace B is "dead" and remove
it.
This patch solves the above issue by appending an PID namespace identifier of
the current process to the lock prefix ("hostname"). It depends on /proc
being mounted properly. But I don't think there is a better way to get pid
namespace identifier reliably.
author | Jun Wu <quark@fb.com> |
---|---|
date | Fri, 10 Feb 2017 13:56:31 -0800 |
parents | b4d117cee636 |
children | 62939e0148f1 |
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# policy.py - module policy logic for Mercurial. # # Copyright 2015 Gregory Szorc <gregory.szorc@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 # Rules for how modules can be loaded. Values are: # # c - require C extensions # allow - allow pure Python implementation when C loading fails # cffi - required cffi versions (implemented within pure module) # cffi-allow - allow pure Python implementation if cffi version is missing # py - only load pure Python modules # # By default, require the C extensions for performance reasons. policy = 'c' policynoc = ('cffi', 'cffi-allow', 'py') policynocffi = ('c', 'py') try: from . import __modulepolicy__ policy = __modulepolicy__.modulepolicy except ImportError: pass # PyPy doesn't load C extensions. # # The canonical way to do this is to test platform.python_implementation(). # But we don't import platform and don't bloat for it here. if '__pypy__' in sys.builtin_module_names: policy = 'cffi' # Our C extensions aren't yet compatible with Python 3. So use pure Python # on Python 3 for now. if sys.version_info[0] >= 3: policy = 'py' # Environment variable can always force settings. policy = os.environ.get('HGMODULEPOLICY', policy)