tests/helpers/utils.py

# Copyright (C) 2018 The Android Open Source Project
#
# 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 time


def exec_fn_with_timeout(func, limit=60):
    """Helper function that executes a given function until it returns True or a
     given time limit is reached.

  Arguments:
    func {function} -- Function to execute. The function can return some output
                    (or None) and as a second return value a boolean indicating,
                    whether the event the function was waiting for has happened.

  Keyword Arguments:
    limit {int} -- Maximum time in seconds to wait for a positive response of
                   the function (default: {60})

  Returns:
    boolean -- False, if the timeout was reached
    any -- Last output of fn
  """

    timeout = time.time() + limit
    while time.time() < timeout:
        output, is_finished = func()
        if is_finished:
            return True, output
    return False, output