# Copyright (c) 2016-present, Facebook, 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.
##############################################################################

## @package extension_loader
# Module caffe2.python.extension_loader
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals
import contextlib
import ctypes
import sys


_set_global_flags = (
    hasattr(sys, 'getdlopenflags') and hasattr(sys, 'setdlopenflags'))


@contextlib.contextmanager
def DlopenGuard():
    if _set_global_flags:
        old_flags = sys.getdlopenflags()
        sys.setdlopenflags(old_flags | ctypes.RTLD_GLOBAL)
    yield
    if _set_global_flags:
        sys.setdlopenflags(old_flags)