151 lines
4.8 KiB
Python
151 lines
4.8 KiB
Python
# Copyright 2012 Red Hat, Inc.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import logging
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import threading
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import eventlet
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from eventlet import greenpool
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from neutron.openstack.common._i18n import _LE
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from neutron.openstack.common import loopingcall
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LOG = logging.getLogger(__name__)
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def _thread_done(gt, *args, **kwargs):
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"""Callback function to be passed to GreenThread.link() when we spawn()
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Calls the :class:`ThreadGroup` to notify if.
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"""
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kwargs['group'].thread_done(kwargs['thread'])
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class Thread(object):
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"""Wrapper around a greenthread, that holds a reference to the
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:class:`ThreadGroup`. The Thread will notify the :class:`ThreadGroup` when
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it has done so it can be removed from the threads list.
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"""
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def __init__(self, thread, group):
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self.thread = thread
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self.thread.link(_thread_done, group=group, thread=self)
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def stop(self):
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self.thread.kill()
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def wait(self):
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return self.thread.wait()
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def link(self, func, *args, **kwargs):
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self.thread.link(func, *args, **kwargs)
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class ThreadGroup(object):
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"""The point of the ThreadGroup class is to:
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* keep track of timers and greenthreads (making it easier to stop them
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when need be).
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* provide an easy API to add timers.
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"""
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def __init__(self, thread_pool_size=10):
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self.pool = greenpool.GreenPool(thread_pool_size)
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self.threads = []
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self.timers = []
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def add_dynamic_timer(self, callback, initial_delay=None,
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periodic_interval_max=None, *args, **kwargs):
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timer = loopingcall.DynamicLoopingCall(callback, *args, **kwargs)
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timer.start(initial_delay=initial_delay,
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periodic_interval_max=periodic_interval_max)
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self.timers.append(timer)
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def add_timer(self, interval, callback, initial_delay=None,
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*args, **kwargs):
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pulse = loopingcall.FixedIntervalLoopingCall(callback, *args, **kwargs)
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pulse.start(interval=interval,
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initial_delay=initial_delay)
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self.timers.append(pulse)
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def add_thread(self, callback, *args, **kwargs):
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gt = self.pool.spawn(callback, *args, **kwargs)
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th = Thread(gt, self)
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self.threads.append(th)
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return th
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def thread_done(self, thread):
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self.threads.remove(thread)
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def _stop_threads(self):
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current = threading.current_thread()
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# Iterate over a copy of self.threads so thread_done doesn't
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# modify the list while we're iterating
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for x in self.threads[:]:
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if x is current:
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# don't kill the current thread.
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continue
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try:
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x.stop()
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except eventlet.greenlet.GreenletExit:
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pass
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except Exception:
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LOG.exception(_LE('Error stopping thread.'))
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def stop_timers(self):
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for x in self.timers:
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try:
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x.stop()
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except Exception:
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LOG.exception(_LE('Error stopping timer.'))
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self.timers = []
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def stop(self, graceful=False):
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"""stop function has the option of graceful=True/False.
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* In case of graceful=True, wait for all threads to be finished.
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Never kill threads.
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* In case of graceful=False, kill threads immediately.
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"""
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self.stop_timers()
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if graceful:
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# In case of graceful=True, wait for all threads to be
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# finished, never kill threads
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self.wait()
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else:
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# In case of graceful=False(Default), kill threads
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# immediately
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self._stop_threads()
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def wait(self):
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for x in self.timers:
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try:
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x.wait()
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except eventlet.greenlet.GreenletExit:
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pass
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except Exception:
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LOG.exception(_LE('Error waiting on ThreadGroup.'))
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current = threading.current_thread()
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# Iterate over a copy of self.threads so thread_done doesn't
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# modify the list while we're iterating
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for x in self.threads[:]:
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if x is current:
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continue
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try:
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x.wait()
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except eventlet.greenlet.GreenletExit:
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pass
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except Exception as ex:
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LOG.exception(ex)
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