vmware-nsx/quantum/openstack/common/loopingcall.py
Clark Boylan b5bf227db4 Perform a sync with oslo-incubator.
This oslo-incubator sync pulls in a new log.py which will make quantum's
default log output format the same as nova, glance and cinder (once
cinder's corresponding oslo sync merges). This common log format
simplifies log indexing as part of CI and makes lives easier for
deployers.

This sync does add a requirement on six as jsonutils depends on it. It
updates install_venv_common.py to be python26 compatible. It also brings
in a bunch of recent python3 compatibility that was added to oslo.

Fixes bug 1183144

Change-Id: Id0f196d7b5680e5950e4a27d66042bf00ccd49e6
2013-05-23 15:58:33 -07:00

148 lines
4.6 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# Copyright 2011 Justin Santa Barbara
# 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 sys
from eventlet import event
from eventlet import greenthread
from quantum.openstack.common.gettextutils import _
from quantum.openstack.common import log as logging
from quantum.openstack.common import timeutils
LOG = logging.getLogger(__name__)
class LoopingCallDone(Exception):
"""Exception to break out and stop a LoopingCall.
The poll-function passed to LoopingCall can raise this exception to
break out of the loop normally. This is somewhat analogous to
StopIteration.
An optional return-value can be included as the argument to the exception;
this return-value will be returned by LoopingCall.wait()
"""
def __init__(self, retvalue=True):
""":param retvalue: Value that LoopingCall.wait() should return."""
self.retvalue = retvalue
class LoopingCallBase(object):
def __init__(self, f=None, *args, **kw):
self.args = args
self.kw = kw
self.f = f
self._running = False
self.done = None
def stop(self):
self._running = False
def wait(self):
return self.done.wait()
class FixedIntervalLoopingCall(LoopingCallBase):
"""A fixed interval looping call."""
def start(self, interval, initial_delay=None):
self._running = True
done = event.Event()
def _inner():
if initial_delay:
greenthread.sleep(initial_delay)
try:
while self._running:
start = timeutils.utcnow()
self.f(*self.args, **self.kw)
end = timeutils.utcnow()
if not self._running:
break
delay = interval - timeutils.delta_seconds(start, end)
if delay <= 0:
LOG.warn(_('task run outlasted interval by %s sec') %
-delay)
greenthread.sleep(delay if delay > 0 else 0)
except LoopingCallDone as e:
self.stop()
done.send(e.retvalue)
except Exception:
LOG.exception(_('in fixed duration looping call'))
done.send_exception(*sys.exc_info())
return
else:
done.send(True)
self.done = done
greenthread.spawn_n(_inner)
return self.done
# TODO(mikal): this class name is deprecated in Havana and should be removed
# in the I release
LoopingCall = FixedIntervalLoopingCall
class DynamicLoopingCall(LoopingCallBase):
"""A looping call which sleeps until the next known event.
The function called should return how long to sleep for before being
called again.
"""
def start(self, initial_delay=None, periodic_interval_max=None):
self._running = True
done = event.Event()
def _inner():
if initial_delay:
greenthread.sleep(initial_delay)
try:
while self._running:
idle = self.f(*self.args, **self.kw)
if not self._running:
break
if periodic_interval_max is not None:
idle = min(idle, periodic_interval_max)
LOG.debug(_('Dynamic looping call sleeping for %.02f '
'seconds'), idle)
greenthread.sleep(idle)
except LoopingCallDone as e:
self.stop()
done.send(e.retvalue)
except Exception:
LOG.exception(_('in dynamic looping call'))
done.send_exception(*sys.exc_info())
return
else:
done.send(True)
self.done = done
greenthread.spawn(_inner)
return self.done