Tab Switching Benchmark for ChromeOS

tools/perf/contrib/cros_benchmarks/cros_utils.py

+# Copyright 2017 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 json
+import logging
+import os
+import subprocess
+import time
+
+import py_utils
+
+from telemetry.core import exceptions
+from telemetry.value import histogram_util
+
+def FindKeyboardDevice(dut_ip):

[cywang, 2017/05/22 09:04:04]

Try to use an emulated keyboard instead(e.g. use evemu-device with a property
file like
https://chromium.googlesource.com/chromiumos/third_party/autotest/+/master/cl...),
so we could still run the test w/o physical keyboard. However, you will need to
remove the emulated device during cleanup.

[vovoy, 2017/05/23 02:26:10]

Done. Using keyboard emulator to send key events.

+  """Find the device that supports events EV=120013.
+  Example /proc/bus/input/devices output for keyboard:
+    I: Bus=0011 Vendor=0001 Product=0001 Version=ab83
+    N: Name="AT Translated Set 2 keyboard"
+    P: Phys=isa0060/serio0/input0
+    S: Sysfs=/devices/platform/i8042/serio0/input/input3
+    U: Uniq=
+    H: Handlers=sysrq event3
+    B: PROP=0
+    B: EV=120013
+    B: KEY=402000000 3803078f800d001 feffffdfffefffff fffffffffffffffe
+    B: MSC=10
+    B: LED=7
+  """
+  cmd =  ['ssh', 'root@' + dut_ip, 'cat', '/proc/bus/input/devices']
+  p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+  out = p.communicate()[0]
+
+  for line in out.splitlines():
+    handler_prefix = 'H: Handlers='
+    kbd_event = 'B: EV=120013'
+    if line.startswith(handler_prefix):
+      handlers = line[len(handler_prefix):].split()
+    elif line.startswith(kbd_event):
+      for handler in handlers:
+        if handler.startswith('event'):
+          return '/dev/input/' + handler
+  raise Exception('keyboard device not found')
+
+def SetupKeyDispatch(dut_ip):
+  """Uploading the script to send key to switch tabs."""
+  cur_dir = os.path.dirname(os.path.abspath(__file__))
+  send_key_filename = cur_dir + '/data/send_key_tab_switch'
+  log_key_filename = cur_dir + '/data/log_key_tab_switch'
+
+  kbd_dev = FindKeyboardDevice(dut_ip)
+  send_key_content = '#!/bin/bash\n'
+  send_key_content += ('evemu-play --insert-slot0 ' + kbd_dev +
+                       ' < /home/root/log_key_tab_switch')
+  with open(send_key_filename, 'w') as f:
+    f.write(send_key_content)
+  os.chmod(send_key_filename, 0774)
+
+  os.system('scp -q %s root@%s:/usr/local/tmp/' % (log_key_filename, dut_ip))
+  os.system('scp -q %s root@%s:/usr/local/tmp/' % (send_key_filename, dut_ip))
+
+def GetTabSwitchHistogram(tab):
+  histogram_name = 'MPArch.RWH_TabSwitchPaintDuration'
+  histogram_type = histogram_util.BROWSER_HISTOGRAM
+  return histogram_util.GetHistogram(
+      histogram_type, histogram_name, tab)
+
+def GetTabSwitchHistogramRetry(browser):
+  """Retry GetHistogram() as it may fail when a context was discarded."""
+  while True:
+    try:
+      # Any tab can be used to get the TabSwitchPaintDuration histogram.
+      # At each retry, try to get valid context again.
+      return GetTabSwitchHistogram(browser.tabs[-1])
+    except exceptions.DevtoolsTargetCrashException:
+      logging.info('GetHistogram: devtools context lost')
+    except KeyError:
+      logging.info('GetHistogram: devtools context lost')
+    except Exception as e:
+      logging.warning('GetHistogram: exception')
+      logging.warning(e)
+    time.sleep(0.5)
+
+def SwitchTab(browser):
+  """Sending Ctrl-tab key to trigger tab switching. Checking the histogram
+  to wait for tab switching completion."""
+  # pylint: disable=protected-access
+  platform_backend = browser._platform_backend
+
+  prev_histogram = GetTabSwitchHistogramRetry(browser)
+
+  platform_backend.RunCommand('/usr/local/tmp/send_key_tab_switch')
+
+  def _IsDone():
+    cur_histogram = GetTabSwitchHistogramRetry(browser)
+
+    diff_histogram = histogram_util.SubtractHistogram(cur_histogram,
+                            prev_histogram)
+    diff_histogram_count = json.loads(diff_histogram).get('count', 0)
+    return diff_histogram_count > 0
+
+  try:
+    py_utils.WaitFor(_IsDone, 10)
+  except py_utils.TimeoutException:
+    logging.warning('wait for histogram timed out')
+
+def NoScreenOff(platform_backend):
+  """Set screen off and dim timer to 1 hour."""
+  platform_backend.RunCommand('set_power_policy --ac_screen_off_delay=3600')
+  platform_backend.RunCommand('set_power_policy --ac_screen_dim_delay=3600')