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
MainEntryPointTimeInternal()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
GetSubsystemStartupTimeHash()32 SubsystemStartupTimeHash* GetSubsystemStartupTimeHash() {
33 static SubsystemStartupTimeHash* slow_startup_time_hash =
34 new SubsystemStartupTimeHash;
35 return slow_startup_time_hash;
36 }
37
GetSubsystemStartupTimeHashLock()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.
RecordMainEntryTimeHistogram()46 void RecordMainEntryTimeHistogram() {
47 const int kLowWordMask = 0xFFFFFFFF;
48 const int kLower31BitsMask = 0x7FFFFFFF;
49 base::TimeDelta browser_main_entry_time_absolute =
50 base::TimeDelta::FromMilliseconds(
51 MainEntryPointTimeInternal()->ToInternalValue() / 1000.0);
52
53 uint64 browser_main_entry_time_raw_ms =
54 browser_main_entry_time_absolute.InMilliseconds();
55
56 base::TimeDelta browser_main_entry_time_raw_ms_high_word =
57 base::TimeDelta::FromMilliseconds(
58 (browser_main_entry_time_raw_ms >> 32) & kLowWordMask);
59 // Shift by one because histograms only support non-negative values.
60 base::TimeDelta browser_main_entry_time_raw_ms_low_word =
61 base::TimeDelta::FromMilliseconds(
62 (browser_main_entry_time_raw_ms >> 1) & kLower31BitsMask);
63
64 // A timestamp is a 64 bit value, yet histograms can only store 32 bits.
65 HISTOGRAM_TIMES("Startup.BrowserMainEntryTimeAbsoluteHighWord",
66 browser_main_entry_time_raw_ms_high_word);
67 HISTOGRAM_TIMES("Startup.BrowserMainEntryTimeAbsoluteLowWord",
68 browser_main_entry_time_raw_ms_low_word);
69 }
70
71 bool g_main_entry_time_was_recorded = false;
72 bool g_startup_stats_collection_finished = false;
73 bool g_was_slow_startup = false;
74
75 // Environment variable that stores the timestamp when the executable's main()
76 // function was entered.
77 const char kChromeMainTimeEnvVar[] = "CHROME_MAIN_TIME";
78
79 } // namespace
80
81 namespace startup_metric_utils {
82
WasNonBrowserUIDisplayed()83 bool WasNonBrowserUIDisplayed() {
84 return g_non_browser_ui_displayed;
85 }
86
SetNonBrowserUIDisplayed()87 void SetNonBrowserUIDisplayed() {
88 g_non_browser_ui_displayed = true;
89 }
90
RecordMainEntryPointTime()91 void RecordMainEntryPointTime() {
92 DCHECK(!g_main_entry_time_was_recorded);
93 g_main_entry_time_was_recorded = true;
94 MainEntryPointTimeInternal();
95 }
96
RecordExeMainEntryTime()97 void RecordExeMainEntryTime() {
98 std::string exe_load_time =
99 base::Int64ToString(base::Time::Now().ToInternalValue());
100 scoped_ptr<base::Environment> env(base::Environment::Create());
101 env->SetVar(kChromeMainTimeEnvVar, exe_load_time);
102 }
103
104 #if defined(OS_ANDROID)
RecordSavedMainEntryPointTime(const base::Time & entry_point_time)105 void RecordSavedMainEntryPointTime(const base::Time& entry_point_time) {
106 DCHECK(!g_main_entry_time_was_recorded);
107 g_main_entry_time_was_recorded = true;
108 *MainEntryPointTimeInternal() = entry_point_time;
109 }
110 #endif // OS_ANDROID
111
112 // Return the time recorded by RecordMainEntryPointTime().
MainEntryStartTime()113 const base::Time MainEntryStartTime() {
114 DCHECK(g_main_entry_time_was_recorded);
115 return *MainEntryPointTimeInternal();
116 }
117
OnBrowserStartupComplete(bool is_first_run)118 void OnBrowserStartupComplete(bool is_first_run) {
119 RecordMainEntryTimeHistogram();
120
121 // Bail if uptime < 7 minutes, to filter out cases where Chrome may have been
122 // autostarted and the machine is under io pressure.
123 const int64 kSevenMinutesInMilliseconds =
124 base::TimeDelta::FromMinutes(7).InMilliseconds();
125 if (base::SysInfo::Uptime() < kSevenMinutesInMilliseconds) {
126 g_startup_stats_collection_finished = true;
127 return;
128 }
129
130 // The Startup.BrowserMessageLoopStartTime histogram recorded in
131 // chrome_browser_main.cc exhibits instability in the field which limits its
132 // usefulness in all scenarios except when we have a very large sample size.
133 // Attempt to mitigate this with a new metric:
134 // * Measure time from main entry rather than the OS' notion of process start
135 // time.
136 // * Only measure launches that occur 7 minutes after boot to try to avoid
137 // cases where Chrome is auto-started and IO is heavily loaded.
138 base::TimeDelta startup_time_from_main_entry =
139 base::Time::Now() - MainEntryStartTime();
140 if (is_first_run) {
141 UMA_HISTOGRAM_LONG_TIMES(
142 "Startup.BrowserMessageLoopStartTimeFromMainEntry.FirstRun",
143 startup_time_from_main_entry);
144 } else {
145 UMA_HISTOGRAM_LONG_TIMES(
146 "Startup.BrowserMessageLoopStartTimeFromMainEntry",
147 startup_time_from_main_entry);
148 }
149
150 // CurrentProcessInfo::CreationTime() is currently only implemented on some
151 // platforms.
152 #if (defined(OS_MACOSX) && !defined(OS_IOS)) || defined(OS_WIN) || \
153 defined(OS_LINUX)
154 // Record timings between process creation, the main() in the executable being
155 // reached and the main() in the shared library being reached.
156 scoped_ptr<base::Environment> env(base::Environment::Create());
157 std::string chrome_main_entry_time_string;
158 if (env->GetVar(kChromeMainTimeEnvVar, &chrome_main_entry_time_string)) {
159 // The time that the Chrome executable's main() function was entered.
160 int64 chrome_main_entry_time_int = 0;
161 if (base::StringToInt64(chrome_main_entry_time_string,
162 &chrome_main_entry_time_int)) {
163 base::Time process_create_time = base::CurrentProcessInfo::CreationTime();
164 base::Time exe_main_time =
165 base::Time::FromInternalValue(chrome_main_entry_time_int);
166 base::Time dll_main_time = MainEntryStartTime();
167
168 // Process create to chrome.exe:main().
169 UMA_HISTOGRAM_LONG_TIMES("Startup.LoadTime.ProcessCreateToExeMain",
170 exe_main_time - process_create_time);
171
172 // chrome.exe:main() to chrome.dll:main().
173 UMA_HISTOGRAM_LONG_TIMES("Startup.LoadTime.ExeMainToDllMain",
174 dll_main_time - exe_main_time);
175
176 // Process create to chrome.dll:main().
177 UMA_HISTOGRAM_LONG_TIMES("Startup.LoadTime.ProcessCreateToDllMain",
178 dll_main_time - process_create_time);
179 }
180 }
181 #endif
182
183 // Record histograms for the subsystem times for startups > 10 seconds.
184 const base::TimeDelta kTenSeconds = base::TimeDelta::FromSeconds(10);
185 if (startup_time_from_main_entry < kTenSeconds) {
186 g_startup_stats_collection_finished = true;
187 return;
188 }
189
190 // If we got here this was what we consider to be a slow startup which we
191 // want to record stats for.
192 g_was_slow_startup = true;
193 }
194
OnInitialPageLoadComplete()195 void OnInitialPageLoadComplete() {
196 if (!g_was_slow_startup)
197 return;
198 DCHECK(!g_startup_stats_collection_finished);
199
200 const base::TimeDelta kStartupTimeMin(
201 base::TimeDelta::FromMilliseconds(1));
202 const base::TimeDelta kStartupTimeMax(base::TimeDelta::FromMinutes(5));
203 static const size_t kStartupTimeBuckets = 100;
204
205 // Set UMA flag for histograms outside chrome/ that can't use the
206 // ScopedSlowStartupUMA class.
207 base::HistogramBase* histogram =
208 base::StatisticsRecorder::FindHistogram("Startup.SlowStartupNSSInit");
209 if (histogram)
210 histogram->SetFlags(base::HistogramBase::kUmaTargetedHistogramFlag);
211
212 // Iterate over the stats recorded by ScopedSlowStartupUMA and create
213 // histograms for them.
214 base::AutoLock locker(*GetSubsystemStartupTimeHashLock());
215 SubsystemStartupTimeHash* time_hash = GetSubsystemStartupTimeHash();
216 for (SubsystemStartupTimeHash::iterator i = time_hash->begin();
217 i != time_hash->end();
218 ++i) {
219 const std::string histogram_name = i->first;
220 base::HistogramBase* counter = base::Histogram::FactoryTimeGet(
221 histogram_name,
222 kStartupTimeMin,
223 kStartupTimeMax,
224 kStartupTimeBuckets,
225 base::Histogram::kUmaTargetedHistogramFlag);
226 counter->AddTime(i->second);
227 }
228
229 g_startup_stats_collection_finished = true;
230 }
231
~ScopedSlowStartupUMA()232 ScopedSlowStartupUMA::~ScopedSlowStartupUMA() {
233 if (g_startup_stats_collection_finished)
234 return;
235
236 base::AutoLock locker(*GetSubsystemStartupTimeHashLock());
237 SubsystemStartupTimeHash* hash = GetSubsystemStartupTimeHash();
238 // Only record the initial sample for a given histogram.
239 if (hash->find(histogram_name_) != hash->end())
240 return;
241
242 (*hash)[histogram_name_] =
243 base::TimeTicks::Now() - start_time_;
244 }
245
246 } // namespace startup_metric_utils
247