old_contents: # -*- coding: utf-8 -*-
  # Copyright 2014 matrix.org
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  
  from twisted.internet import defer
  
  import logging
  
  
  logger = logging.getLogger(__name__)
  
  
  class Lock(object):
  
      def __init__(self, deferred):
          self._deferred = deferred
          self.released = False
  
      def release(self):
          self.released = True
          self._deferred.callback(None)
  
      def __del__(self):
          if not self.released:
              logger.critical("Lock was destructed but never released!")
              self.release()
  
      def __enter__(self):
              return self
  
      def __exit__(self, type, value, traceback):
          self.release()
  
  
  class LockManager(object):
      """ Utility class that allows us to lock based on a `key` """
  
      def __init__(self):
          self._lock_deferreds = {}
  
      @defer.inlineCallbacks
      def lock(self, key):
          """ Allows us to block until it is our turn.
          Args:
              key (str)
          Returns:
              Lock
          """
          new_deferred = defer.Deferred()
          old_deferred = self._lock_deferreds.get(key)
          self._lock_deferreds[key] = new_deferred
  
          if old_deferred:
              yield old_deferred
  
          defer.returnValue(Lock(new_deferred))
  
new_contents: # -*- coding: utf-8 -*-
  # Copyright 2014 matrix.org
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  
  from twisted.internet import defer
  
  import logging
  
  
  logger = logging.getLogger(__name__)
  
  
  class Lock(object):
  
      def __init__(self, deferred, key):
          self._deferred = deferred
          self.released = False
          self.key = key
  
      def release(self):
          self.released = True
          self._deferred.callback(None)
  
      def __del__(self):
          if not self.released:
              logger.critical("Lock was destructed but never released!")
              self.release()
  
      def __enter__(self):
          return self
  
      def __exit__(self, type, value, traceback):
          logger.debug("Releasing lock for key=%r", self.key)
          self.release()
  
  
  class LockManager(object):
      """ Utility class that allows us to lock based on a `key` """
  
      def __init__(self):
          self._lock_deferreds = {}
  
      @defer.inlineCallbacks
      def lock(self, key):
          """ Allows us to block until it is our turn.
          Args:
              key (str)
          Returns:
              Lock
          """
          new_deferred = defer.Deferred()
          old_deferred = self._lock_deferreds.get(key)
          self._lock_deferreds[key] = new_deferred
  
          if old_deferred:
              logger.debug("Queueing on lock for key=%r", key)
              yield old_deferred
              logger.debug("Obtained lock for key=%r", key)
          else:
              logger.debug("Entering uncontended lock for key=%r", key)
  
          defer.returnValue(Lock(new_deferred, key))
  
subject: Put some DEBUG logging in lockutils.py so we can debug roomlocks