src/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 histogram_util
  16 from metrics import power
  17 from telemetry.core import util
  18 from telemetry.page import page_measurement
  19 from telemetry.value import histogram
  20
  21 # TODO: Revisit this test once multitab support is finalized.
  22
  23 class TabSwitching(page_measurement.PageMeasurement):
  24   def __init__(self):
  25     super(TabSwitching, self).__init__()
  26     self._first_page_in_pageset = True
  27     self._power_metric = power.PowerMetric()
  28
  29   def CustomizeBrowserOptions(self, options):
  30     options.AppendExtraBrowserArgs([
  31         '--enable-stats-collection-bindings'
  32     ])
  33     power.PowerMetric.CustomizeBrowserOptions(options)
  34
  35   def DidStartBrowser(self, browser):
  36     self._first_page_in_pageset = True
  37
  38   def TabForPage(self, page, browser):
  39     if self._first_page_in_pageset:
  40       # The initial browser window contains a single tab, navigate that tab
  41       # rather than creating a new one.
  42       self._first_page_in_pageset = False
  43       return browser.tabs[0]
  44
  45     return browser.tabs.New()
  46
  47   def StopBrowserAfterPage(self, browser, page):
  48     # Restart the browser after the last page in the pageset.
  49     return len(browser.tabs) >= len(page.page_set.pages)
  50
  51   def MeasurePage(self, page, tab, results):
  52     """On the last tab, cycle through each tab that was opened and then record
  53     a single histogram for the tab switching metric."""
  54     if len(tab.browser.tabs) != len(page.page_set.pages):
  55       return
  56
  57     # Measure power usage of tabs after quiescence.
  58     util.WaitFor(tab.HasReachedQuiescence, 60)
  59
  60     self._power_metric.Start(page, tab)
  61     time.sleep(60)
  62     self._power_metric.Stop(page, tab)
  63     self._power_metric.AddResults(tab, results,)
  64
  65     histogram_name = 'MPArch.RWH_TabSwitchPaintDuration'
  66     histogram_type = histogram_util.BROWSER_HISTOGRAM
  67     display_name = 'MPArch_RWH_TabSwitchPaintDuration'
  68     first_histogram = histogram_util.GetHistogram(
  69         histogram_type, histogram_name, tab)
  70     prev_histogram = first_histogram
  71
  72     for i in xrange(len(tab.browser.tabs)):
  73       t = tab.browser.tabs[i]
  74       t.Activate()
  75       def _IsDone():
  76         cur_histogram = histogram_util.GetHistogram(
  77             histogram_type, histogram_name, tab)
  78         diff_histogram = histogram_util.SubtractHistogram(
  79             cur_histogram, prev_histogram)
  80         return diff_histogram
  81       util.WaitFor(_IsDone, 30)
  82       prev_histogram = histogram_util.GetHistogram(
  83           histogram_type, histogram_name, tab)
  84
  85     last_histogram = histogram_util.GetHistogram(
  86         histogram_type, histogram_name, tab)
  87     diff_histogram = histogram_util.SubtractHistogram(last_histogram,
  88         first_histogram)
  89
  90     results.AddSummaryValue(
  91         histogram.HistogramValue(None, display_name, '',
  92                                  raw_value_json=diff_histogram,
  93                                  important=False))