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 first_histogram = histogram_util.GetHistogram( 52 histogram_type, histogram_name, tab) 53 prev_histogram = first_histogram 54 55 for i in xrange(len(tab.browser.tabs)): 56 t = tab.browser.tabs[i] 57 t.Activate() 58 def _IsDone(): 59 cur_histogram = histogram_util.GetHistogram( 60 histogram_type, histogram_name, tab) 61 diff_histogram = histogram_util.SubtractHistogram( 62 cur_histogram, prev_histogram) 63 return diff_histogram 64 util.WaitFor(_IsDone, 30) 65 prev_histogram = histogram_util.GetHistogram( 66 histogram_type, histogram_name, tab) 67 68 last_histogram = histogram_util.GetHistogram( 69 histogram_type, histogram_name, tab) 70 diff_histogram = histogram_util.SubtractHistogram(last_histogram, 71 first_histogram) 72 73 results.AddSummary(histogram_name, '', diff_histogram, 74 data_type='unimportant-histogram') 75
