src/components/startup_metric_utils/startup_metric_utils.cc

   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 #include "components/startup_metric_utils/startup_metric_utils.h"
   6
   7 #include "base/containers/hash_tables.h"
   8 #include "base/environment.h"
   9 #include "base/logging.h"
  10 #include "base/metrics/histogram.h"
  11 #include "base/metrics/histogram_base.h"
  12 #include "base/metrics/statistics_recorder.h"
  13 #include "base/process/process_info.h"
  14 #include "base/strings/string_number_conversions.h"
  15 #include "base/synchronization/lock.h"
  16 #include "base/sys_info.h"
  17 #include "base/time/time.h"
  18
  19 namespace {
  20
  21 // Mark as volatile to defensively make sure usage is thread-safe.
  22 // Note that at the time of this writing, access is only on the UI thread.
  23 volatile bool g_non_browser_ui_displayed = false;
  24
  25 base::Time* MainEntryPointTimeInternal() {
  26   static base::Time main_start_time = base::Time::Now();
  27   return &main_start_time;
  28 }
  29
  30 typedef base::hash_map<std::string,base::TimeDelta> SubsystemStartupTimeHash;
  31
  32 SubsystemStartupTimeHash* GetSubsystemStartupTimeHash() {
  33   static SubsystemStartupTimeHash* slow_startup_time_hash =
  34                                     new SubsystemStartupTimeHash;
  35   return slow_startup_time_hash;
  36 }
  37
  38 base::Lock* GetSubsystemStartupTimeHashLock() {
  39   static base::Lock* slow_startup_time_hash_lock = new base::Lock;
  40   return slow_startup_time_hash_lock;
  41 }
  42
  43 // Record time of main entry so it can be read from Telemetry performance
  44 // tests.
  45 // TODO(jeremy): Remove once crbug.com/317481 is fixed.
  46 void RecordMainEntryTimeHistogram() {
  47   const int kLowWordMask = 0xFFFFFFFF;
  48   const int kLower31BitsMask = 0x7FFFFFFF;
  49   base::TimeDelta browser_main_entry_time_absolute =
  50       *MainEntryPointTimeInternal() - base::Time::UnixEpoch();
  51
  52   uint64 browser_main_entry_time_raw_ms =
  53       browser_main_entry_time_absolute.InMilliseconds();
  54
  55   base::TimeDelta browser_main_entry_time_raw_ms_high_word =
  56       base::TimeDelta::FromMilliseconds(
  57           (browser_main_entry_time_raw_ms >> 32) & kLowWordMask);
  58   // Shift by one because histograms only support non-negative values.
  59   base::TimeDelta browser_main_entry_time_raw_ms_low_word =
  60       base::TimeDelta::FromMilliseconds(
  61           (browser_main_entry_time_raw_ms >> 1) & kLower31BitsMask);
  62
  63   // A timestamp is a 64 bit value, yet histograms can only store 32 bits.
  64   LOCAL_HISTOGRAM_TIMES("Startup.BrowserMainEntryTimeAbsoluteHighWord",
  65       browser_main_entry_time_raw_ms_high_word);
  66   LOCAL_HISTOGRAM_TIMES("Startup.BrowserMainEntryTimeAbsoluteLowWord",
  67       browser_main_entry_time_raw_ms_low_word);
  68 }
  69
  70 bool g_main_entry_time_was_recorded = false;
  71 bool g_startup_stats_collection_finished = false;
  72 bool g_was_slow_startup = false;
  73
  74 // Environment variable that stores the timestamp when the executable's main()
  75 // function was entered.
  76 const char kChromeMainTimeEnvVar[] = "CHROME_MAIN_TIME";
  77
  78 }  // namespace
  79
  80 namespace startup_metric_utils {
  81
  82 bool WasNonBrowserUIDisplayed() {
  83   return g_non_browser_ui_displayed;
  84 }
  85
  86 void SetNonBrowserUIDisplayed() {
  87   g_non_browser_ui_displayed = true;
  88 }
  89
  90 void RecordMainEntryPointTime() {
  91   DCHECK(!g_main_entry_time_was_recorded);
  92   g_main_entry_time_was_recorded = true;
  93   MainEntryPointTimeInternal();
  94 }
  95
  96 void RecordExeMainEntryTime() {
  97   std::string exe_load_time =
  98       base::Int64ToString(base::Time::Now().ToInternalValue());
  99   scoped_ptr<base::Environment> env(base::Environment::Create());
 100   env->SetVar(kChromeMainTimeEnvVar, exe_load_time);
 101 }
 102
 103 #if defined(OS_ANDROID)
 104 void RecordSavedMainEntryPointTime(const base::Time& entry_point_time) {
 105   DCHECK(!g_main_entry_time_was_recorded);
 106   g_main_entry_time_was_recorded = true;
 107   *MainEntryPointTimeInternal() = entry_point_time;
 108 }
 109 #endif // OS_ANDROID
 110
 111 // Return the time recorded by RecordMainEntryPointTime().
 112 const base::Time MainEntryStartTime() {
 113   DCHECK(g_main_entry_time_was_recorded);
 114   return *MainEntryPointTimeInternal();
 115 }
 116
 117 void OnBrowserStartupComplete(bool is_first_run) {
 118   RecordMainEntryTimeHistogram();
 119
 120   // Bail if uptime < 7 minutes, to filter out cases where Chrome may have been
 121   // autostarted and the machine is under io pressure.
 122   const int64 kSevenMinutesInMilliseconds =
 123       base::TimeDelta::FromMinutes(7).InMilliseconds();
 124   if (base::SysInfo::Uptime() < kSevenMinutesInMilliseconds) {
 125     g_startup_stats_collection_finished = true;
 126     return;
 127   }
 128
 129   // The Startup.BrowserMessageLoopStartTime histogram recorded in
 130   // chrome_browser_main.cc exhibits instability in the field which limits its
 131   // usefulness in all scenarios except when we have a very large sample size.
 132   // Attempt to mitigate this with a new metric:
 133   // * Measure time from main entry rather than the OS' notion of process start
 134   //   time.
 135   // * Only measure launches that occur 7 minutes after boot to try to avoid
 136   //   cases where Chrome is auto-started and IO is heavily loaded.
 137   base::TimeDelta startup_time_from_main_entry =
 138       base::Time::Now() - MainEntryStartTime();
 139   if (is_first_run) {
 140     UMA_HISTOGRAM_LONG_TIMES(
 141         "Startup.BrowserMessageLoopStartTimeFromMainEntry.FirstRun",
 142         startup_time_from_main_entry);
 143   } else {
 144     UMA_HISTOGRAM_LONG_TIMES(
 145         "Startup.BrowserMessageLoopStartTimeFromMainEntry",
 146         startup_time_from_main_entry);
 147   }
 148
 149 // CurrentProcessInfo::CreationTime() is currently only implemented on some
 150 // platforms.
 151 #if (defined(OS_MACOSX) && !defined(OS_IOS)) || defined(OS_WIN) || \
 152     defined(OS_LINUX)
 153   // Record timings between process creation, the main() in the executable being
 154   // reached and the main() in the shared library being reached.
 155   scoped_ptr<base::Environment> env(base::Environment::Create());
 156   std::string chrome_main_entry_time_string;
 157   if (env->GetVar(kChromeMainTimeEnvVar, &chrome_main_entry_time_string)) {
 158     // The time that the Chrome executable's main() function was entered.
 159     int64 chrome_main_entry_time_int = 0;
 160     if (base::StringToInt64(chrome_main_entry_time_string,
 161                             &chrome_main_entry_time_int)) {
 162       base::Time process_create_time = base::CurrentProcessInfo::CreationTime();
 163       base::Time exe_main_time =
 164           base::Time::FromInternalValue(chrome_main_entry_time_int);
 165       base::Time dll_main_time = MainEntryStartTime();
 166
 167       // Process create to chrome.exe:main().
 168       UMA_HISTOGRAM_LONG_TIMES("Startup.LoadTime.ProcessCreateToExeMain",
 169                                exe_main_time - process_create_time);
 170
 171       // chrome.exe:main() to chrome.dll:main().
 172       UMA_HISTOGRAM_LONG_TIMES("Startup.LoadTime.ExeMainToDllMain",
 173                                dll_main_time - exe_main_time);
 174
 175       // Process create to chrome.dll:main().
 176       UMA_HISTOGRAM_LONG_TIMES("Startup.LoadTime.ProcessCreateToDllMain",
 177                                dll_main_time - process_create_time);
 178     }
 179   }
 180 #endif
 181
 182   // Record histograms for the subsystem times for startups > 10 seconds.
 183   const base::TimeDelta kTenSeconds = base::TimeDelta::FromSeconds(10);
 184   if (startup_time_from_main_entry < kTenSeconds) {
 185     g_startup_stats_collection_finished = true;
 186     return;
 187   }
 188
 189   // If we got here this was what we consider to be a slow startup which we
 190   // want to record stats for.
 191   g_was_slow_startup = true;
 192 }
 193
 194 void OnInitialPageLoadComplete() {
 195   if (!g_was_slow_startup)
 196     return;
 197   DCHECK(!g_startup_stats_collection_finished);
 198
 199   const base::TimeDelta kStartupTimeMin(
 200       base::TimeDelta::FromMilliseconds(1));
 201   const base::TimeDelta kStartupTimeMax(base::TimeDelta::FromMinutes(5));
 202   static const size_t kStartupTimeBuckets = 100;
 203
 204   // Set UMA flag for histograms outside chrome/ that can't use the
 205   // ScopedSlowStartupUMA class.
 206   base::HistogramBase* histogram =
 207       base::StatisticsRecorder::FindHistogram("Startup.SlowStartupNSSInit");
 208   if (histogram)
 209     histogram->SetFlags(base::HistogramBase::kUmaTargetedHistogramFlag);
 210
 211   // Iterate over the stats recorded by ScopedSlowStartupUMA and create
 212   // histograms for them.
 213   base::AutoLock locker(*GetSubsystemStartupTimeHashLock());
 214   SubsystemStartupTimeHash* time_hash = GetSubsystemStartupTimeHash();
 215   for (SubsystemStartupTimeHash::iterator i = time_hash->begin();
 216       i != time_hash->end();
 217       ++i) {
 218     const std::string histogram_name = i->first;
 219     base::HistogramBase* counter = base::Histogram::FactoryTimeGet(
 220         histogram_name,
 221         kStartupTimeMin,
 222         kStartupTimeMax,
 223         kStartupTimeBuckets,
 224         base::Histogram::kUmaTargetedHistogramFlag);
 225     counter->AddTime(i->second);
 226   }
 227
 228   g_startup_stats_collection_finished = true;
 229 }
 230
 231 const base::Time* MainEntryPointTime() {
 232   if (!g_main_entry_time_was_recorded)
 233     return NULL;
 234   return MainEntryPointTimeInternal();
 235 }
 236
 237 ScopedSlowStartupUMA::~ScopedSlowStartupUMA() {
 238   if (g_startup_stats_collection_finished)
 239     return;
 240
 241   base::AutoLock locker(*GetSubsystemStartupTimeHashLock());
 242   SubsystemStartupTimeHash* hash = GetSubsystemStartupTimeHash();
 243   // Only record the initial sample for a given histogram.
 244   if (hash->find(histogram_name_) !=  hash->end())
 245     return;
 246
 247   (*hash)[histogram_name_] =
 248       base::TimeTicks::Now() - start_time_;
 249 }
 250
 251 }  // namespace startup_metric_utils