Mercurial > hg
view mercurial/dirstateguard.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 | 751639bf6fc4 |
children | ec306bc6915b |
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# dirstateguard.py - class to allow restoring dirstate after failure # # Copyright 2005-2007 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 .i18n import _ from . import ( error, ) class dirstateguard(object): '''Restore dirstate at unexpected failure. At the construction, this class does: - write current ``repo.dirstate`` out, and - save ``.hg/dirstate`` into the backup file This restores ``.hg/dirstate`` from backup file, if ``release()`` is invoked before ``close()``. This just removes the backup file at ``close()`` before ``release()``. ''' def __init__(self, repo, name): self._repo = repo self._active = False self._closed = False self._suffix = '.backup.%s.%d' % (name, id(self)) repo.dirstate.savebackup(repo.currenttransaction(), self._suffix) self._active = True def __del__(self): if self._active: # still active # this may occur, even if this class is used correctly: # for example, releasing other resources like transaction # may raise exception before ``dirstateguard.release`` in # ``release(tr, ....)``. self._abort() def close(self): if not self._active: # already inactivated msg = (_("can't close already inactivated backup: dirstate%s") % self._suffix) raise error.Abort(msg) self._repo.dirstate.clearbackup(self._repo.currenttransaction(), self._suffix) self._active = False self._closed = True def _abort(self): self._repo.dirstate.restorebackup(self._repo.currenttransaction(), self._suffix) self._active = False def release(self): if not self._closed: if not self._active: # already inactivated msg = (_("can't release already inactivated backup:" " dirstate%s") % self._suffix) raise error.Abort(msg) self._abort()