1a6dc73254
This code is appearing in various projects (currently oslo.messaging, taskflow, oslo.concurrency) and it seems better placed in this little utility helper to avoid people from duplicating it. Change-Id: I177d79d4561b3eb13822d3e2ae4a9fbe011f586a
117 lines
5.1 KiB
Python
117 lines
5.1 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright (C) 2015 Yahoo! Inc. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import threading
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import warnings
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from oslo_utils import importutils
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# These may or may not exist; so carefully import them if we can...
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_eventlet = importutils.try_import('eventlet')
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_patcher = importutils.try_import('eventlet.patcher')
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# Attribute that can be used by others to see if eventlet is even currently
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# useable (can be used in unittests to skip test cases or test classes that
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# require eventlet to work).
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EVENTLET_AVAILABLE = all((_eventlet, _patcher))
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# Taken from eventlet.py (v0.16.1) patcher code (it's not a accessible set
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# for some reason...)
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_ALL_PATCH = frozenset(['__builtin__', 'MySQLdb', 'os',
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'psycopg', 'select', 'socket', 'thread', 'time'])
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def fetch_current_thread_functor():
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# Until https://github.com/eventlet/eventlet/issues/172 is resolved
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# or addressed we have to use complicated workaround to get a object
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# that will not be recycled; the usage of threading.current_thread()
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# doesn't appear to currently be monkey patched and therefore isn't
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# reliable to use (and breaks badly when used as all threads share
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# the same current_thread() object)...
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if not EVENTLET_AVAILABLE:
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return threading.current_thread
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else:
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green_threaded = _patcher.is_monkey_patched('thread')
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if green_threaded:
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return _eventlet.getcurrent
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else:
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return threading.current_thread
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def warn_eventlet_not_patched(expected_patched_modules=None,
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what='this library'):
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"""Warns if eventlet is being used without patching provided modules.
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:param expected_patched_modules: list of modules to check to ensure that
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they are patched (and to warn if they
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are not); these names should correspond
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to the names passed into the eventlet
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monkey_patch() routine. If not provided
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then *all* the modules that could be
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patched are checked. The currently valid
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selection is one or multiple of
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['MySQLdb', '__builtin__', 'all', 'os',
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'psycopg', 'select', 'socket', 'thread',
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'time'] (where 'all' has an inherent
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special meaning).
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:type expected_patched_modules: list/tuple/iterable
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:param what: string to merge into the warnings message to identify
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what is being checked (used in forming the emitted warnings
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message).
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:type what: string
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"""
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if not expected_patched_modules:
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expanded_patched_modules = _ALL_PATCH.copy()
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else:
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expanded_patched_modules = set()
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for m in expected_patched_modules:
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if m == 'all':
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expanded_patched_modules.update(_ALL_PATCH)
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else:
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if m not in _ALL_PATCH:
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raise ValueError("Unknown module '%s' requested to check"
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" if patched" % m)
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else:
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expanded_patched_modules.add(m)
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if EVENTLET_AVAILABLE:
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try:
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# The patcher code stores a dictionary here of all modules
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# names -> whether it was patched...
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#
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# Example:
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#
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# >>> _patcher.monkey_patch(os=True)
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# >>> print(_patcher.already_patched)
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# {'os': True}
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maybe_patched = bool(_patcher.already_patched)
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except AttributeError:
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# Assume it is patched (the attribute used here doesn't appear
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# to be a public documented API so we will assume that everything
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# is patched when that attribute isn't there to be safe...)
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maybe_patched = True
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if maybe_patched:
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not_patched = []
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for m in sorted(expanded_patched_modules):
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if not _patcher.is_monkey_patched(m):
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not_patched.append(m)
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if not_patched:
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warnings.warn("It is highly recommended that when eventlet"
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" is used that the %s modules are monkey"
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" patched when using %s (to avoid"
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" spurious or unexpected lock-ups"
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" and/or hangs)" % (not_patched, what),
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RuntimeWarning, stacklevel=3)
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