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# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# Copyright 2011 Justin Santa Barbara
# Copyright 2019 Red Hat, 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
# 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.
"""Enable eventlet monkey patching."""
import os
def _monkey_patch():
# NOTE(mdbooth): Anything imported here will not be monkey patched. It is
# important to take care not to import anything here which requires monkey
# patching.
# NOTE(artom) eventlet processes environment variables at import-time.
# as such any eventlet configuration should happen here if needed.
import eventlet
import sys
# NOTE(mdbooth): Imports only sys (2019-01-30). Other modules imported at
# runtime on execution of debugger.init().
from nova import debugger
# Note any modules with known monkey-patching issues which have been
# imported before monkey patching.
# urllib3:
# oslo_context.context:
problems = (set(['urllib3', 'oslo_context.context']) &
if debugger.enabled():
# turn off thread patching to enable the remote debugger
elif == 'nt':
# for nova-compute running on Windows(Hyper-v)
# pipes don't support non-blocking I/O
# Monkey patch the original current_thread to use the up-to-date _active
# global variable. See and
import __original_module_threading as orig_threading
import threading
orig_threading.current_thread.__globals__['_active'] = threading._active
# NOTE(mdbooth): Log here instead of earlier to avoid loading oslo logging
# before monkey patching.
# NOTE(mdbooth): Ideally we would raise an exception here, as this is
# likely to cause problems when executing nova code. However, some non-nova
# tools load nova only to extract metadata and do not execute it. Two
# examples are oslopolicy-policy-generator and sphinx, both of which can
# fail if we assert here. It is not ideal that these utilities are monkey
# patching at all, but we should not break them.
# TODO(mdbooth): If there is any way to reliably determine if we are being
# loaded in that kind of context without breaking existing callers, we
# should do it and bypass monkey patching here entirely.
if problems:
from oslo_log import log as logging
LOG = logging.getLogger(__name__)
LOG.warning("Modules with known eventlet monkey patching issues were "
"imported prior to eventlet monkey patching: %s. This "
"warning can usually be ignored if the caller is only "
"importing and not executing nova code.",
', '.join(problems))
# NOTE(mdbooth): This workaround is required to avoid breaking sphinx. See
# separate comment in doc/source/ It may also be useful for other
# non-nova utilities. Ideally the requirement for this workaround will be
# removed as soon as possible, so do not rely on, or extend it.
if (os.environ.get('OS_NOVA_DISABLE_EVENTLET_PATCHING', '').lower()
not in ('1', 'true', 'yes')):