/usr/lib/python2.7/dist-packages/oslo_messaging/_drivers/pool.py is in python-oslo.messaging 4.6.1-2ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 | # Copyright 2013 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 abc
import collections
import threading
from oslo_log import log as logging
import six
from oslo_messaging._drivers import common
LOG = logging.getLogger(__name__)
@six.add_metaclass(abc.ABCMeta)
class Pool(object):
"""A thread-safe object pool.
Modelled after the eventlet.pools.Pool interface, but designed to be safe
when using native threads without the GIL.
Resizing is not supported.
"""
def __init__(self, max_size=4):
super(Pool, self).__init__()
self._max_size = max_size
self._current_size = 0
self._cond = threading.Condition()
self._items = collections.deque()
def put(self, item):
"""Return an item to the pool."""
with self._cond:
self._items.appendleft(item)
self._cond.notify()
def get(self):
"""Return an item from the pool, when one is available.
This may cause the calling thread to block.
"""
with self._cond:
while True:
try:
return self._items.popleft()
except IndexError:
pass
if self._current_size < self._max_size:
self._current_size += 1
break
# FIXME(markmc): timeout needed to allow keyboard interrupt
# http://bugs.python.org/issue8844
self._cond.wait(timeout=1)
# We've grabbed a slot and dropped the lock, now do the creation
try:
return self.create()
except Exception:
with self._cond:
self._current_size -= 1
raise
def iter_free(self):
"""Iterate over free items."""
with self._cond:
while True:
try:
yield self._items.popleft()
except IndexError:
break
@abc.abstractmethod
def create(self):
"""Construct a new item."""
class ConnectionPool(Pool):
"""Class that implements a Pool of Connections."""
def __init__(self, conf, rpc_conn_pool_size, url, connection_cls):
self.connection_cls = connection_cls
self.conf = conf
self.url = url
super(ConnectionPool, self).__init__(rpc_conn_pool_size)
self.reply_proxy = None
# TODO(comstud): Timeout connections not used in a while
def create(self, purpose=None):
if purpose is None:
purpose = common.PURPOSE_SEND
LOG.debug('Pool creating new connection')
return self.connection_cls(self.conf, self.url, purpose)
def empty(self):
for item in self.iter_free():
item.close()
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