# Copyright (c) 2013 Rackspace Hosting
#
#    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.

"""This modules stubs out functions in nova.utils."""

from nova import utils


def stub_out_utils_spawn_n(stubs):
    """Stubs out spawn_n with a blocking version.

    This aids testing async processes by blocking until they're done.
    """
    def no_spawn(func, *args, **kwargs):
        return func(*args, **kwargs)

    stubs.Set(utils, 'spawn_n', no_spawn)

# Copyright (c) 2013 Rackspace Hosting
#
#    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.

"""This modules stubs out functions in nova.utils."""

from nova import utils


def stub_out_utils_spawn_n(stubs):
    """Stubs out spawn_n with a blocking version.

    This aids testing async processes by blocking until they're done.
    """
    def no_spawn(func, *args, **kwargs):
        try:
            return func(*args, **kwargs)
        except Exception:
            # NOTE(danms): This is supposed to simulate spawning
            # of a thread, which would run separate from the parent,
            # and die silently on error. If we don't catch and discard
            # any exceptions here, we're not honoring the usual
            # behavior.
            pass

    stubs.Set(utils, 'spawn_n', no_spawn)

Make spawn_n() stub properly ignore errors in the child thread work
Make spawn_n() stub properly ignore errors in the child thread work

When we call spawn_n() normally, we fork off a thread that can run or
die on its own, without affecting the parent. In unit tests, we stub
this out to be a synchronous call, but we allow any exceptions that
occur in that work to bubble up to the caller. This is not normal
behavior and thus we should discard any such exceptions in order to
mimic actual behavior of a child thread.

Change-Id: I35ab21e9525aa76cced797436daa0b99a4fa99f2
Related-bug: #1349147
