vmware-nsx/vmware_nsx/common/locking.py
asarfaty b6bd7e49d1 Remove some pylint exclusions
Change-Id: I6909c10471039f1e68224679ceeb2867ab5a3a47
2020-09-30 10:32:46 +02:00

69 lines
2.5 KiB
Python

# Copyright 2015 VMware, Inc.
# All Rights Reserved
#
# 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.
import os
import traceback
from oslo_concurrency import lockutils
from oslo_config import cfg
from oslo_log import log
from tooz import coordination
LOG = log.getLogger(__name__)
class LockManager(object):
_coordinator = None
_coordinator_pid = None
_connect_string = cfg.CONF.locking_coordinator_url
def __init__(self):
LOG.debug('LockManager initialized!')
@staticmethod
def get_lock(name, **kwargs):
if cfg.CONF.locking_coordinator_url:
lck = LockManager._get_lock_distributed(name)
LOG.debug('Lock %s taken with stack trace %s', name,
traceback.extract_stack(limit=5))
return lck
# Ensure that external=True
kwargs['external'] = True
lck = LockManager._get_lock_local(name, **kwargs)
LOG.debug('Lock %s taken with stack trace %s', name,
traceback.extract_stack(limit=5))
return lck
@staticmethod
def _get_lock_local(name, **kwargs):
return lockutils.lock(name, **kwargs)
@staticmethod
def _get_lock_distributed(name):
if LockManager._coordinator_pid != os.getpid():
# We should use a per-process coordinator. If PID is different
# start a new coordinator.
# While the API workers are spawned, we have to re-initialize
# a coordinator, so we validate that the PID is still the same.
LockManager._coordinator_pid = os.getpid()
LOG.debug('Initialized coordinator with connect string %s',
LockManager._connect_string)
LockManager._coordinator = coordination.get_coordinator(
LockManager._connect_string, 'vmware-neutron-plugin')
LockManager._coordinator.start()
LOG.debug('Retrieved lock for %s', name)
return LockManager._coordinator.get_lock(name)