Up process priority during login.

client/cros/login.py

 # Copyright (c) 2010 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 errno, logging, os, re, signal, subprocess, time
 import common
 import constants, cros_logging, cros_ui, cryptohome
 from autotest_lib.client.bin import utils
 from autotest_lib.client.common_lib import error
 
 
 _DEFAULT_TIMEOUT = 30
 
+# Priority increase to use when logging in to make sure we aren't descheduled at
+# inopportune times.
+_LOGIN_NICE = 20
+
 # Log messages used to signal when we're in a logout situation. Used to detect
 # crashes by cros_ui_test.UITest.
 LOGOUT_ATTEMPT_MSG = 'cros/login.py: Attempting logout...'
 LOGOUT_COMPLETE_MSG = 'cros/login.py: Logout complete.'
 
 
 class TimeoutError(error.TestError):
     """Error raised when we time out while waiting on a condition."""
     pass
 
@@ skipping 115 matching lines @@
         raise UnexpectedCondition("Session manager is not running")
 
     if logged_in():
         raise UnexpectedCondition("Already logged in")
 
     # Mark /var/log/messages now; we'll run through all subsequent log messages
     # if we couldn't log in to see if the browser crashed.
     log_reader = cros_logging.LogReader()
     log_reader.set_start_by_current()
 
-    ax = cros_ui.get_autox()
-    # navigate to login screen
-    ax.send_hotkey("Ctrl+Alt+L")
-    # escape out of any login screen menus (e.g., the network selection menu)
-    ax.send_hotkey("Escape")
-    time.sleep(0.5)
-    if (username):
-        # focus username
-        ax.send_hotkey("Alt+U")
-        ax.send_text(username)
-        # TODO(rginda): remove Tab after http://codereview.chromium.org/1390003
-        ax.send_hotkey("Tab")
-        # focus password
-        ax.send_hotkey("Alt+P")
-        ax.send_text(password)
-        ax.send_hotkey("Return")
-    else:
-        ax.send_hotkey("Alt+B")  # Browse without signing-in
+    # Up our priority so we don't get descheduled in the middle of sending key
+    # press and key release events.
+    utils.system('renice +%d -p %d' % (_LOGIN_NICE, os.getpid()))
+    try:
+      ax = cros_ui.get_autox()
+      # navigate to login screen
+      ax.send_hotkey("Ctrl+Alt+L")
+      # escape out of any login screen menus (e.g., the network selection menu)
+      ax.send_hotkey("Escape")
+      time.sleep(0.5)
+      if (username):
+          # focus username
+          ax.send_hotkey("Alt+U")
+          ax.send_text(username)
+          # focus password
+          ax.send_hotkey("Alt+P")
+          ax.send_text(password)
+          ax.send_hotkey("Return")
+      else:
+          ax.send_hotkey("Alt+B")  # Browse without signing-in
+    finally:
+      utils.system('renice -%d -p %d' % (_LOGIN_NICE, os.getpid()))
 
     wait_for_condition(condition=logged_in,
                        timeout_msg='Timed out waiting for login',
                        timeout=timeout,
                        process='chrome',
                        log_reader=log_reader,
                        crash_msg='Chrome crashed during login')
 
 
 def attempt_logout(timeout=_DEFAULT_TIMEOUT):
@@ skipping 215 matching lines @@
     except (IOError, OSError) as error:
         logging.error(error)
 
     # Restart the UI.
     nuke_login_manager()
     utils.poll_for_condition(
         lambda: __session_manager_restarted(oldpid),
         TimeoutError('Timed out waiting for logout'),
         timeout)
     wait_for_login_prompt()