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 """
  11
  12 import time
  13
  14 from metrics import cpu
  15 from metrics import histogram_util
  16 from telemetry.core import util
  17 from telemetry.page import page_measurement
  18
  19 # TODO: Revisit this test once multitab support is finalized.
  20
  21 class TabSwitching(page_measurement.PageMeasurement):
  22   def __init__(self):
  23     super(TabSwitching, self).__init__()
  24     self._cpu_metric = None
  25
  26   def CustomizeBrowserOptions(self, options):
  27     options.AppendExtraBrowserArgs([
  28         '--enable-stats-collection-bindings'
  29     ])
  30
  31   def TabForPage(self, page, browser):
  32     return browser.tabs.New()
  33
  34   def DidStartBrowser(self, browser):
  35     self._cpu_metric = cpu.CpuMetric(browser)
  36
  37   def MeasurePage(self, page, tab, results):
  38     """On the last tab, cycle through each tab that was opened and then record
  39     a single histogram for the tab switching metric."""
  40     if len(tab.browser.tabs) != len(page.page_set.pages):
  41       return
  42     self._cpu_metric.Start(page, tab)
  43     time.sleep(.5)
  44     self._cpu_metric.Stop(page, tab)
  45     # Calculate the idle cpu load before any actions are done.
  46     self._cpu_metric.AddResults(tab, results,
  47                                 'idle_cpu_utilization')
  48
  49     histogram_name = 'MPArch.RWH_TabSwitchPaintDuration'
  50     histogram_type = histogram_util.BROWSER_HISTOGRAM
  51     display_name = 'MPArch_RWH_TabSwitchPaintDuration'
  52     first_histogram = histogram_util.GetHistogram(
  53         histogram_type, histogram_name, tab)
  54     prev_histogram = first_histogram
  55
  56     for i in xrange(len(tab.browser.tabs)):
  57       t = tab.browser.tabs[i]
  58       t.Activate()
  59       def _IsDone():
  60         cur_histogram = histogram_util.GetHistogram(
  61             histogram_type, histogram_name, tab)
  62         diff_histogram = histogram_util.SubtractHistogram(
  63             cur_histogram, prev_histogram)
  64         return diff_histogram
  65       util.WaitFor(_IsDone, 30)
  66       prev_histogram = histogram_util.GetHistogram(
  67           histogram_type, histogram_name, tab)
  68
  69     last_histogram = histogram_util.GetHistogram(
  70         histogram_type, histogram_name, tab)
  71     diff_histogram = histogram_util.SubtractHistogram(last_histogram,
  72         first_histogram)
  73
  74     results.AddSummary(display_name, '', diff_histogram,
  75         data_type='unimportant-histogram')