Source code for taurus.core.util.lock

#!/usr/bin/env python

#############################################################################
##
# This file is part of Taurus
##
# http://taurus-scada.org
##
# Copyright 2011 CELLS / ALBA Synchrotron, Bellaterra, Spain
##
# Taurus is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
##
# Taurus is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
##
# You should have received a copy of the GNU Lesser General Public License
# along with Taurus.  If not, see <http://www.gnu.org/licenses/>.
##
#############################################################################

"""This module defines a *slow* lock class that provides additional debugging
information"""

from builtins import object
import threading
import logging

__all__ = ["TaurusLock"]

__docformat__ = 'restructuredtext'

_VERBOSE = False


[docs]def TaurusLock(verbose=None, name=None, lock=None): if verbose is None: verbose = _VERBOSE if verbose: return _TaurusLock(name=name, lock=lock) if lock is None: return threading.Lock() return lock
class _TaurusLock(object): """A sardana lock""" def __init__(self, name=None, lock=None, level=logging.DEBUG): name = name or self.__class__.__name__ self.__name = name self.__logger = logging.getLogger(name=name) self.__level = level if lock is None: lock = threading.Lock() self.__block = lock self.__owner = None def __repr__(self): owner = self.__owner if owner is not None: owner = owner.name return "<%s owner=%r>" % (self.__name, owner) def owner_name(self): owner = self.__owner if owner is not None: return owner.name def _note(self, msg, *args): self.__logger.log(self.__level, msg, *args) def acquire(self, blocking=1): if __debug__: self._note("[START] acquire(%s) [owner=%s]", blocking, self.owner_name()) rc = self.__block.acquire(blocking) me = threading.current_thread() if rc: self.__owner = me state = "success" else: state = "failure" if __debug__: self._note("[ END ] acquire(%s) %s [owner=%s]", blocking, state, self.owner_name()) return rc __enter__ = acquire def release(self): if __debug__: self._note("[START] release() [owner=%s]", self.owner_name()) self.__block.release() self.__owner = None if __debug__: self._note("[ END ] release() [owner=%s]", self.owner_name()) def __exit__(self, t, v, tb): self.release()