Add sleep after restarting usb ports and before checking for devices.

build/android/buildbot/bb_device_status_check.py

 #!/usr/bin/env python
 #
 # Copyright 2013 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.
 
 """A class to keep track of devices across builds and report state."""
 import logging
 import optparse
 import os
 import psutil
+import re
 import signal
 import smtplib
 import subprocess
 import sys
-import re
+import time
 import urllib
 
 import bb_annotations
 import bb_utils
 
 sys.path.append(os.path.join(os.path.dirname(__file__),
                              os.pardir, os.pardir, 'util', 'lib',
                              'common'))
 import perf_tests_results_helper  # pylint: disable=F0401
 
@@ skipping 77 matching lines @@
   # Causing the device status check step fail for slow install speed or low
   # battery currently is too disruptive to the bots (especially try bots).
   # Turn off devices with low battery and the step does not fail.
   if battery_level < 15:
     device_adb.EnableAdbRoot()
     device_adb.Shutdown()
   full_report = '\n'.join(report)
   return device_type, device_build, battery_level, full_report, errors, True
 
 
+def GetLastDevices(out_dir):
+  """Returns a list of devices that have been seen on the bot.
+
+  Args:
+    options: out_dir parameter of options argument is used as the base
+             directory to load and update the cache file.
+
+  Returns: List of device serial numbers that were on the bot.
+  """
+  devices_path = os.path.join(out_dir, '.last_devices')
+  devices = []
+  try:
+    with open(devices_path) as f:
+      devices = f.read().splitlines()
+  except IOError:
+    # Ignore error, file might not exist
+    pass
+  return devices
+
+
 def CheckForMissingDevices(options, adb_online_devs):
   """Uses file of previous online devices to detect broken phones.
 
   Args:
     options: out_dir parameter of options argument is used as the base
              directory to load and update the cache file.
     adb_online_devs: A list of serial numbers of the currently visible
                      and online attached devices.
   """
   # TODO(navabi): remove this once the bug that causes different number
   # of devices to be detected between calls is fixed.
   logger = logging.getLogger()
   logger.setLevel(logging.INFO)
 
   out_dir = os.path.abspath(options.out_dir)
 
-  def ReadDeviceList(file_name):
-    devices_path = os.path.join(out_dir, file_name)
-    devices = []
-    try:
-      with open(devices_path) as f:
-        devices = f.read().splitlines()
-    except IOError:
-      # Ignore error, file might not exist
-      pass
-    return devices
-
   def WriteDeviceList(file_name, device_list):
     path = os.path.join(out_dir, file_name)
     if not os.path.exists(out_dir):
       os.makedirs(out_dir)
     with open(path, 'w') as f:
       # Write devices currently visible plus devices previously seen.
       f.write('\n'.join(set(device_list)))
 
   last_devices_path = os.path.join(out_dir, '.last_devices')
-  last_devices = ReadDeviceList('.last_devices')
+  last_devices = GetLastDevices(out_dir)
   missing_devs = list(set(last_devices) - set(adb_online_devs))
 
   all_known_devices = list(set(adb_online_devs) | set(last_devices))
   WriteDeviceList('.last_devices', all_known_devices)
   WriteDeviceList('.last_missing', missing_devs)
 
   if not all_known_devices:
     # This can happen if for some reason the .last_devices file is not
     # present or if it was empty.
     return ['No online devices. Have any devices been plugged in?']
@@ skipping 109 matching lines @@
                     help='Will not check if devices are provisioned properly.')
   parser.add_option('--device-status-dashboard', action='store_true',
                     help='Output device status data for dashboard.')
   parser.add_option('--restart-usb', action='store_true',
                     help='Restart USB ports before running device check.')
   options, args = parser.parse_args()
   if args:
     parser.error('Unknown options %s' % args)
 
   if options.restart_usb:
-    KillAllAdb()
-    rc = RestartUsb()
-    if rc:
-      return 1
+    expected_devices = GetLastDevices(os.path.abspath(options.out_dir))
+    devices = android_commands.GetAttachedDevices()
+    # Only restart usb if devices are missing
+    if set(expected_devices) != set(devices):
+      KillAllAdb()
+      if RestartUsb():
+        return 1
+      retries = 5
+      while retries:
+        time.sleep(1)
+        devices = android_commands.GetAttachedDevices()
+        if set(expected_devices) == set(devices):
+          break
+        retries -= 1
 
   devices = android_commands.GetAttachedDevices()
   # TODO(navabi): Test to make sure this fails and then fix call
   offline_devices = android_commands.GetAttachedDevices(hardware=False,
                                                         emulator=False,
                                                         offline=True)
 
   types, builds, batteries, reports, errors = [], [], [], [], []
   fail_step_lst = []
   if devices:
@@ skipping 36 matching lines @@
     # devices with critically low battery or install speed. Remove those devices
     # from testing, allowing build to continue with good devices.
     return 1
 
   if not devices:
     return 1
 
 
 if __name__ == '__main__':
   sys.exit(main())