tacker/tacker/openstack/common/threadgroup.py

130 lines
4.1 KiB
Python

# Copyright 2012 Red Hat, Inc.
#
# 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 eventlet
from eventlet import greenpool
from eventlet import greenthread
from tacker.openstack.common import log as logging
from tacker.openstack.common import loopingcall
LOG = logging.getLogger(__name__)
def _thread_done(gt, *args, **kwargs):
"""Callback function to be passed to GreenThread.link() when we spawn()
Calls the :class:`ThreadGroup` to notify if.
"""
kwargs['group'].thread_done(kwargs['thread'])
class Thread(object):
"""Wrapper around a greenthread, that holds a reference to the
:class:`ThreadGroup`. The Thread will notify the :class:`ThreadGroup` when
it has done so it can be removed from the threads list.
"""
def __init__(self, thread, group):
self.thread = thread
self.thread.link(_thread_done, group=group, thread=self)
def stop(self):
self.thread.kill()
def wait(self):
return self.thread.wait()
def link(self, func, *args, **kwargs):
self.thread.link(func, *args, **kwargs)
class ThreadGroup(object):
"""The point of the ThreadGroup classis to:
* keep track of timers and greenthreads (making it easier to stop them
when need be).
* provide an easy API to add timers.
"""
def __init__(self, thread_pool_size=10):
self.pool = greenpool.GreenPool(thread_pool_size)
self.threads = []
self.timers = []
def add_dynamic_timer(self, callback, initial_delay=None,
periodic_interval_max=None, *args, **kwargs):
timer = loopingcall.DynamicLoopingCall(callback, *args, **kwargs)
timer.start(initial_delay=initial_delay,
periodic_interval_max=periodic_interval_max)
self.timers.append(timer)
def add_timer(self, interval, callback, initial_delay=None,
*args, **kwargs):
pulse = loopingcall.FixedIntervalLoopingCall(callback, *args, **kwargs)
pulse.start(interval=interval,
initial_delay=initial_delay)
self.timers.append(pulse)
def add_thread(self, callback, *args, **kwargs):
gt = self.pool.spawn(callback, *args, **kwargs)
th = Thread(gt, self)
self.threads.append(th)
return th
def thread_done(self, thread):
self.threads.remove(thread)
def stop(self):
current = greenthread.getcurrent()
# Iterate over a copy of self.threads so thread_done doesn't
# modify the list while we're iterating
for x in self.threads[:]:
if x is current:
# don't kill the current thread.
continue
try:
x.stop()
except Exception as ex:
LOG.exception(ex)
for x in self.timers:
try:
x.stop()
except Exception as ex:
LOG.exception(ex)
self.timers = []
def wait(self):
for x in self.timers:
try:
x.wait()
except eventlet.greenlet.GreenletExit:
pass
except Exception as ex:
LOG.exception(ex)
current = greenthread.getcurrent()
# Iterate over a copy of self.threads so thread_done doesn't
# modify the list while we're iterating
for x in self.threads[:]:
if x is current:
continue
try:
x.wait()
except eventlet.greenlet.GreenletExit:
pass
except Exception as ex:
LOG.exception(ex)