client/site_tests/cheets_Midis/cheets_Midis.py

# Copyright 2018 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import logging

from autotest_lib.client.common_lib import error
from autotest_lib.client.common_lib.cros import arc
from autotest_lib.client.common_lib.cros import chrome
from autotest_lib.client.bin import test
from autotest_lib.client.bin import utils
from autotest_lib.client.cros import cros_ui


TIMEOUT=5
SLEEP_INTERVAL=1


class cheets_Midis(test.test):
    """ Test to verify midis daemon starts correctly.

    A simple test which verifies whether:
    - midis starts up correctly on ARC container start-up.
    - midis restarts correctly on logging-out and then
      logging back in.
    """
    version = 2

    def _get_midis_pid(self):
        """ Get the midis daemon pid using pgrep. """
        cmd = 'pgrep midis'
        result = utils.run(cmd, ignore_status=True).stdout
        try:
            return int(result)
        except ValueError:
            logging.error('Error parsing pgrep result: %s', result)
            return None

    def _poll_for_midis_pid(self):
        """ Repeatedly calls _get_midis_pid, until we succeed or timeout. """
        try:
            return utils.poll_for_condition(condition=self._get_midis_pid,
                                            timeout=TIMEOUT,
                                            sleep_interval=SLEEP_INTERVAL)
        except utils.TimeoutError:
            logging.error('Timed out waiting for midis')
            return None

    def _start_chrome_and_get_pid(self):
        """ Starts up a Chrome instance, logs in and trys to find a midis
        pid, then logs out.

        Returns:
        - valid integer pid on success
        - None on failure.
        """
        midis_pid = None
        session = None
        with chrome.Chrome(
            arc_mode=arc.arc_common.ARC_MODE_ENABLED,
            dont_override_profile=False) as cr:
            session = cros_ui.get_chrome_session_ident()
            midis_pid = self._poll_for_midis_pid()
        # Wait for the login screen to appear before returning.
        cros_ui.wait_for_chrome_ready(session)
        return midis_pid

    def run_once(self):
        """ Start up Chrome with ARC twice and check that midis also
        starts both times, and is killed when we log out.
        """

        old_midis_pid = self._start_chrome_and_get_pid()
        if old_midis_pid == None:
            raise error.TestFail('midis not running after Chrome login.')

        new_midis_pid = self._start_chrome_and_get_pid()
        if new_midis_pid == None:
            raise error.TestFail('midis didn\'t restart on Chrome OS re login')
        if new_midis_pid == old_midis_pid:
            raise error.TestFail('midis not killed after first Chrome log-out.')