1389b63213
In some cases, when we call the "BaseWorker.start" method (eg: use oslo_service.service.ProcessLanuch to pull up the worker), we cannot pass the "desc" parameter, so we need to pass in the desc parameter during initialization. this patch move the "desc" parameter to the initialization, when call "start" method, if set "desc", it will be used first. if not, "desc" passed in initialization are used. this design solves the problem and keeps compatibility. Partial-bug: #1910623 Change-Id: I4df8c319308224175a7f735cfc966b1080caa227
112 lines
3.8 KiB
Python
112 lines
3.8 KiB
Python
# 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
|
|
|
|
from oslo_service import service
|
|
import setproctitle
|
|
|
|
from neutron_lib.callbacks import events
|
|
from neutron_lib.callbacks import registry
|
|
from neutron_lib.callbacks import resources
|
|
|
|
|
|
class BaseWorker(service.ServiceBase):
|
|
"""Partial implementation of the ServiceBase ABC.
|
|
|
|
Subclasses will still need to add the other abstract methods defined in
|
|
service.ServiceBase. See oslo_service for more details.
|
|
|
|
If a plugin needs to handle synchronization with the Neutron database and
|
|
do this only once instead of in every API worker, for instance, it would
|
|
define a BaseWorker class and the plugin would have get_workers return
|
|
an array of BaseWorker instances. For example:
|
|
|
|
.. code-block:: python
|
|
|
|
class MyPlugin(...):
|
|
def get_workers(self):
|
|
return [MyPluginWorker()]
|
|
|
|
class MyPluginWorker(BaseWorker):
|
|
def start(self):
|
|
super(MyPluginWorker, self).start()
|
|
do_sync()
|
|
"""
|
|
|
|
# default class value for case when super().__init__ is not called
|
|
_default_process_count = 1
|
|
|
|
def __init__(self, worker_process_count=_default_process_count,
|
|
set_proctitle='on', desc=None):
|
|
"""Initialize a worker instance.
|
|
|
|
:param worker_process_count: Defines how many processes to spawn for
|
|
worker:
|
|
0 - spawn 1 new worker thread,
|
|
1..N - spawn N new worker processes
|
|
set_proctitle:
|
|
'off' - do not change process title
|
|
'on' - set process title to descriptive string and parent
|
|
'brief' - set process title to descriptive string
|
|
desc:
|
|
process descriptive string
|
|
"""
|
|
self._worker_process_count = worker_process_count
|
|
self._my_pid = os.getpid()
|
|
self._set_proctitle = set_proctitle
|
|
if set_proctitle == 'on':
|
|
self._parent_proctitle = setproctitle.getproctitle()
|
|
self.desc = desc
|
|
|
|
@property
|
|
def worker_process_count(self):
|
|
"""The worker's process count.
|
|
|
|
:returns: The number of processes to spawn for this worker.
|
|
"""
|
|
return self._worker_process_count
|
|
|
|
def setproctitle(self, name="neutron-server", desc=None):
|
|
if self._set_proctitle == "off" or os.getpid() == self._my_pid:
|
|
return
|
|
|
|
if not desc:
|
|
desc = self.__class__.__name__
|
|
|
|
proctitle = "%s: %s" % (name, desc)
|
|
if self._set_proctitle == "on":
|
|
proctitle += " (%s)" % self._parent_proctitle
|
|
|
|
setproctitle.setproctitle(proctitle)
|
|
|
|
def start(self, name="neutron-server", desc=None):
|
|
"""Start the worker.
|
|
|
|
If worker_process_count is greater than 0, a callback notification
|
|
is sent. Subclasses should call this method before doing their
|
|
own start() work.
|
|
|
|
Automatically sets the process title to indicate that this is a
|
|
child worker, customizable via the name and desc arguments.
|
|
|
|
:returns: None
|
|
"""
|
|
|
|
# If we are a child process, set our proctitle to something useful
|
|
desc = desc or self.desc
|
|
self.setproctitle(name, desc)
|
|
if self.worker_process_count > 0:
|
|
registry.notify(resources.PROCESS, events.AFTER_INIT, self.start)
|