build/android/pylib/local/emulator/local_emulator_environment.py

# Copyright 2019 The Chromium 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 devil.utils import parallelizer
from pylib.local.device import local_device_environment
from pylib.local.emulator import avd

# Mirroring https://bit.ly/2OjuxcS#23
_MAX_ANDROID_EMULATORS = 16


class LocalEmulatorEnvironment(local_device_environment.LocalDeviceEnvironment):

  def __init__(self, args, output_manager, error_func):
    super(LocalEmulatorEnvironment, self).__init__(args, output_manager,
                                                   error_func)
    self._avd_config = avd.AvdConfig(args.avd_config)
    if args.emulator_count < 1:
      error_func('--emulator-count must be >= 1')
    elif args.emulator_count >= _MAX_ANDROID_EMULATORS:
      logging.warning('--emulator-count capped at 16.')
    self._emulator_count = min(_MAX_ANDROID_EMULATORS, args.emulator_count)
    self._emulator_instances = []
    self._device_serials = []

  #override
  def SetUp(self):
    self._avd_config.Install()

    emulator_instances = [
        self._avd_config.CreateInstance() for _ in range(self._emulator_count)
    ]

    def start_emulator_instance(e):
      try:
        e.Start()
        return e
      except avd.AvdException:
        logging.exception('Failed to start emulator instance.')
        return None

    parallel_emulators = parallelizer.SyncParallelizer(emulator_instances)
    self._emulator_instances = [
        emu
        for emu in parallel_emulators.pMap(start_emulator_instance).pGet(None)
        if emu is not None
    ]
    self._device_serials = [e.serial for e in self._emulator_instances]

    if not self._emulator_instances:
      raise Exception('Failed to start any instances of the emulator.')
    elif len(self._emulator_instances) < self._emulator_count:
      logging.warning(
          'Running with fewer emulator instances than requested (%d vs %d)',
          len(self._emulator_instances), self._emulator_count)

    super(LocalEmulatorEnvironment, self).SetUp()

  #override
  def TearDown(self):
    try:
      super(LocalEmulatorEnvironment, self).TearDown()
    finally:
      parallelizer.SyncParallelizer(self._emulator_instances).Stop()