tools/perf/measurements/tab_switching.py

   1 # Copyright 2013 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 """The tab switching measurement.
   6
   7 This measurement opens pages in different tabs. After all the tabs have opened,
   8 it cycles through each tab in sequence, and records a histogram of the time
   9 between when a tab was first requested to be shown, and when it was painted.
  10 Power usage is also measured.
  11 """
  12
  13 import time
  14
  15 from metrics import keychain_metric
  16 from metrics import power
  17 from telemetry.core import util
  18 from telemetry.page import page_test
  19 from telemetry.value import histogram
  20 from telemetry.value import histogram_util
  21
  22 # TODO: Revisit this test once multitab support is finalized.
  23
  24 class TabSwitching(page_test.PageTest):
  25
  26   # Amount of time to measure, in seconds.
  27   SAMPLE_TIME = 30
  28
  29   def __init__(self):
  30     super(TabSwitching, self).__init__(action_name_to_run='RunPageInteractions')
  31     self._first_page_in_pageset = True
  32     self._power_metric = None
  33
  34   def CustomizeBrowserOptions(self, options):
  35     keychain_metric.KeychainMetric.CustomizeBrowserOptions(options)
  36
  37     options.AppendExtraBrowserArgs([
  38         '--enable-stats-collection-bindings'
  39     ])
  40     # Enable background networking so we can test its impact on power usage.
  41     options.disable_background_networking = False
  42     power.PowerMetric.CustomizeBrowserOptions(options)
  43
  44   def WillStartBrowser(self, platform):
  45     self._first_page_in_pageset = True
  46     self._power_metric = power.PowerMetric(platform, TabSwitching.SAMPLE_TIME)
  47
  48   def TabForPage(self, page, browser):
  49     if self._first_page_in_pageset:
  50       # The initial browser window contains a single tab, navigate that tab
  51       # rather than creating a new one.
  52       self._first_page_in_pageset = False
  53       return browser.tabs[0]
  54
  55     return browser.tabs.New()
  56
  57   def StopBrowserAfterPage(self, browser, page):
  58     # Restart the browser after the last page in the pageset.
  59     return len(browser.tabs) >= len(page.page_set.pages)
  60
  61   def ValidateAndMeasurePage(self, page, tab, results):
  62     """On the last tab, cycle through each tab that was opened and then record
  63     a single histogram for the tab switching metric."""
  64     if len(tab.browser.tabs) != len(page.page_set.pages):
  65       return
  66
  67     # Measure power usage of tabs after quiescence.
  68     util.WaitFor(tab.HasReachedQuiescence, 60)
  69
  70     if tab.browser.platform.CanMonitorPower():
  71       self._power_metric.Start(page, tab)
  72       time.sleep(TabSwitching.SAMPLE_TIME)
  73       self._power_metric.Stop(page, tab)
  74       self._power_metric.AddResults(tab, results,)
  75
  76     histogram_name = 'MPArch.RWH_TabSwitchPaintDuration'
  77     histogram_type = histogram_util.BROWSER_HISTOGRAM
  78     display_name = 'MPArch_RWH_TabSwitchPaintDuration'
  79     first_histogram = histogram_util.GetHistogram(
  80         histogram_type, histogram_name, tab)
  81     prev_histogram = first_histogram
  82
  83     for i in xrange(len(tab.browser.tabs)):
  84       t = tab.browser.tabs[i]
  85       t.Activate()
  86       def _IsDone():
  87         cur_histogram = histogram_util.GetHistogram(
  88             histogram_type, histogram_name, tab)
  89         diff_histogram = histogram_util.SubtractHistogram(
  90             cur_histogram, prev_histogram)
  91         return diff_histogram
  92       util.WaitFor(_IsDone, 30)
  93       prev_histogram = histogram_util.GetHistogram(
  94           histogram_type, histogram_name, tab)
  95
  96     last_histogram = histogram_util.GetHistogram(
  97         histogram_type, histogram_name, tab)
  98     diff_histogram = histogram_util.SubtractHistogram(last_histogram,
  99         first_histogram)
 100
 101     results.AddSummaryValue(
 102         histogram.HistogramValue(None, display_name, 'ms',
 103                                  raw_value_json=diff_histogram,
 104                                  important=False))
 105
 106     keychain_metric.KeychainMetric().AddResults(tab, results)