e70032d0d9
In order to avoid the circular import in threading utils move the decorators functionality to utils/misc and move the locking functionality to utils/lock_utils and then use these functions from the threading util (and elsewhere). Fixes bug: 1236080 Change-Id: I9e71c2ba15782cbb6dd5ab7e1264b77ed47bc29e
112 lines
3.7 KiB
Python
112 lines
3.7 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
|
|
|
# Copyright (C) 2013 Yahoo! Inc. 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 logging
|
|
import multiprocessing
|
|
import threading
|
|
import time
|
|
import types
|
|
|
|
from taskflow.utils import lock_utils
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
def await(check_functor, timeout=None):
|
|
"""Spin-loops + sleeps awaiting for a given functor to return true."""
|
|
if timeout is not None:
|
|
end_time = time.time() + max(0, timeout)
|
|
else:
|
|
end_time = None
|
|
# Use the same/similar scheme that the python condition class uses.
|
|
delay = 0.0005
|
|
while not check_functor():
|
|
time.sleep(delay)
|
|
if end_time is not None:
|
|
remaining = end_time - time.time()
|
|
if remaining <= 0:
|
|
return False
|
|
delay = min(delay * 2, remaining, 0.05)
|
|
else:
|
|
delay = min(delay * 2, 0.05)
|
|
return True
|
|
|
|
|
|
def get_optimal_thread_count():
|
|
"""Try to guess optimal thread count for current system."""
|
|
try:
|
|
return multiprocessing.cpu_count() + 1
|
|
except NotImplementedError:
|
|
# NOTE(harlowja): apparently may raise so in this case we will
|
|
# just setup two threads since its hard to know what else we
|
|
# should do in this situation.
|
|
return 2
|
|
|
|
|
|
class CountDownLatch(object):
|
|
"""Similar in concept to the java count down latch."""
|
|
|
|
def __init__(self, count=0):
|
|
self.count = count
|
|
self.lock = threading.Condition()
|
|
|
|
def countDown(self):
|
|
with self.lock:
|
|
self.count -= 1
|
|
if self.count <= 0:
|
|
self.lock.notifyAll()
|
|
|
|
def await(self, timeout=None):
|
|
end_time = None
|
|
if timeout is not None:
|
|
timeout = max(0, timeout)
|
|
end_time = time.time() + timeout
|
|
time_up = False
|
|
with self.lock:
|
|
while True:
|
|
# Stop waiting on these 2 conditions.
|
|
if time_up or self.count <= 0:
|
|
break
|
|
# Was this a spurious wakeup or did we really end??
|
|
self.lock.wait(timeout=timeout)
|
|
if end_time is not None:
|
|
if time.time() >= end_time:
|
|
time_up = True
|
|
else:
|
|
# Reduce the timeout so that we don't wait extra time
|
|
# over what we initially were requested to.
|
|
timeout = end_time - time.time()
|
|
return self.count <= 0
|
|
|
|
|
|
class ThreadSafeMeta(type):
|
|
"""Metaclass that adds locking to all pubic methods of a class"""
|
|
|
|
def __new__(cls, name, bases, attrs):
|
|
for attr_name, attr_value in attrs.iteritems():
|
|
if isinstance(attr_value, types.FunctionType):
|
|
if attr_name[0] != '_':
|
|
attrs[attr_name] = lock_utils.locked(attr_value)
|
|
return super(ThreadSafeMeta, cls).__new__(cls, name, bases, attrs)
|
|
|
|
def __call__(cls, *args, **kwargs):
|
|
instance = super(ThreadSafeMeta, cls).__call__(*args, **kwargs)
|
|
if not hasattr(instance, '_lock'):
|
|
instance._lock = threading.RLock()
|
|
return instance
|