heat/heat/openstack/common/threadgroup.py

120 lines
3.5 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# 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.
from eventlet import greenlet
from eventlet import greenpool
from eventlet import greenthread
from heat.openstack.common.gettextutils import _
from heat.openstack.common import log as logging
from heat.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 ThreadGroup to notify if.
'''
kwargs['group'].thread_done(kwargs['thread'])
class Thread(object):
"""
Wrapper around a greenthread, that holds a reference to
the ThreadGroup. The Thread will notify the ThreadGroup
when it has done so it can be removed from the threads
list.
"""
def __init__(self, name, thread, group):
self.name = name
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()
class ThreadGroup(object):
"""
The point of this class is 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, name, thread_pool_size=10):
self.name = name
self.pool = greenpool.GreenPool(thread_pool_size)
self.threads = []
self.timers = []
def add_timer(self, interval, callback, initial_delay=None,
*args, **kwargs):
pulse = loopingcall.LoopingCall(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(callback.__name__, gt, self)
self.threads.append(th)
def thread_done(self, thread):
self.threads.remove(thread)
def stop(self):
current = greenthread.getcurrent()
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 greenlet.GreenletExit:
pass
except Exception as ex:
LOG.exception(ex)
current = greenthread.getcurrent()
for x in self.threads:
if x is current:
continue
try:
x.wait()
except greenlet.GreenletExit:
pass
except Exception as ex:
LOG.exception(ex)