#!/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
"""
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()