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// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "components/startup_metric_utils/startup_metric_utils.h"
#include "base/containers/hash_tables.h"
#include "base/environment.h"
#include "base/logging.h"
#include "base/metrics/histogram_macros.h"
#include "base/process/process_info.h"
#include "base/strings/string_number_conversions.h"
#include "base/sys_info.h"
#include "base/time/time.h"
#if defined(OS_WIN)
#include <winternl.h>
#include "base/win/windows_version.h"
#endif
namespace {
// Mark as volatile to defensively make sure usage is thread-safe.
// Note that at the time of this writing, access is only on the UI thread.
volatile bool g_non_browser_ui_displayed = false;
base::Time* MainEntryPointTimeInternal() {
static base::Time main_start_time = base::Time::Now();
return &main_start_time;
}
#if defined(OS_WIN)
// The struct used to return system process information via the NT internal
// QuerySystemInformation call. This is partially documented at
// http://goo.gl/Ja9MrH and fully documented at http://goo.gl/QJ70rn
// This structure is laid out in the same format on both 32-bit and 64-bit
// systems, but has a different size due to the various pointer-sized fields.
struct SYSTEM_PROCESS_INFORMATION_EX {
ULONG NextEntryOffset;
ULONG NumberOfThreads;
LARGE_INTEGER WorkingSetPrivateSize;
ULONG HardFaultCount;
BYTE Reserved1[36];
PVOID Reserved2[3];
// This is labeled a handle so that it expands to the correct size for 32-bit
// and 64-bit operating systems. However, under the hood it's a 32-bit DWORD
// containing the process ID.
HANDLE UniqueProcessId;
PVOID Reserved3;
ULONG HandleCount;
BYTE Reserved4[4];
PVOID Reserved5[11];
SIZE_T PeakPagefileUsage;
SIZE_T PrivatePageCount;
LARGE_INTEGER Reserved6[6];
// Array of SYSTEM_THREAD_INFORMATION structs follows.
};
// The signature of the NtQuerySystemInformation function.
typedef NTSTATUS (WINAPI *NtQuerySystemInformationPtr)(
SYSTEM_INFORMATION_CLASS, PVOID, ULONG, PULONG);
// Gets the hard fault count of the current process, returning it via
// |hard_fault_count|. Returns true on success, false otherwise. Also returns
// whether or not the system call was even possible for the current OS version
// via |has_os_support|.
bool GetHardFaultCountForCurrentProcess(uint32_t* hard_fault_count,
bool* has_os_support) {
DCHECK(hard_fault_count);
DCHECK(has_os_support);
if (base::win::GetVersion() < base::win::VERSION_WIN7) {
*has_os_support = false;
return false;
}
// At this point the OS supports the required system call.
*has_os_support = true;
// Get the function pointer.
NtQuerySystemInformationPtr query_sys_info =
reinterpret_cast<NtQuerySystemInformationPtr>(
::GetProcAddress(GetModuleHandle(L"ntdll.dll"),
"NtQuerySystemInformation"));
if (query_sys_info == nullptr)
return false;
// The output of this system call depends on the number of threads and
// processes on the entire system, and this can change between calls. Retry
// a small handful of times growing the buffer along the way.
// NOTE: The actual required size depends entirely on the number of processes
// and threads running on the system. The initial guess suffices for
// ~100s of processes and ~1000s of threads.
std::vector<uint8_t> buffer(32 * 1024);
for (size_t tries = 0; tries < 3; ++tries) {
ULONG return_length = 0;
NTSTATUS status = query_sys_info(
SystemProcessInformation,
buffer.data(),
static_cast<ULONG>(buffer.size()),
&return_length);
// Insufficient space in the buffer.
if (return_length > buffer.size()) {
buffer.resize(return_length);
continue;
}
if (NT_SUCCESS(status) && return_length <= buffer.size())
break;
return false;
}
// Look for the struct housing information for the current process.
DWORD proc_id = ::GetCurrentProcessId();
size_t index = 0;
while (index < buffer.size()) {
DCHECK_LE(index + sizeof(SYSTEM_PROCESS_INFORMATION_EX), buffer.size());
SYSTEM_PROCESS_INFORMATION_EX* proc_info =
reinterpret_cast<SYSTEM_PROCESS_INFORMATION_EX*>(buffer.data() + index);
if (reinterpret_cast<DWORD>(proc_info->UniqueProcessId) == proc_id) {
*hard_fault_count = proc_info->HardFaultCount;
return true;
}
// The list ends when NextEntryOffset is zero. This also prevents busy
// looping if the data is in fact invalid.
if (proc_info->NextEntryOffset <= 0)
return false;
index += proc_info->NextEntryOffset;
}
return false;
}
#endif // defined(OS_WIN)
// On Windows, records the number of hard-faults that have occurred in the
// current chrome.exe process since it was started. This is a nop on other
// platforms.
// crbug.com/476923
// TODO(chrisha): If this proves useful, use it to split startup stats in two.
void RecordHardFaultHistogram(bool is_first_run) {
#if defined(OS_WIN)
uint32_t hard_fault_count = 0;
bool has_os_support = false;
bool success = GetHardFaultCountForCurrentProcess(
&hard_fault_count, &has_os_support);
// Log whether or not the system call was successful, assuming the OS was
// detected to support it.
if (has_os_support) {
UMA_HISTOGRAM_BOOLEAN(
"Startup.BrowserMessageLoopStartHardFaultCount.Success",
success);
}
// Don't log a histogram value if unable to get the hard fault count.
if (!success)
return;
// Hard fault counts are expected to be in the thousands range,
// corresponding to faulting in ~10s of MBs of code ~10s of KBs at a time.
// (Observed to vary from 1000 to 10000 on various test machines and
// platforms.)
if (is_first_run) {
UMA_HISTOGRAM_CUSTOM_COUNTS(
"Startup.BrowserMessageLoopStartHardFaultCount.FirstRun",
hard_fault_count,
0, 40000, 50);
} else {
UMA_HISTOGRAM_CUSTOM_COUNTS(
"Startup.BrowserMessageLoopStartHardFaultCount",
hard_fault_count,
0, 40000, 50);
}
#endif // defined(OS_WIN)
}
// Record time of main entry so it can be read from Telemetry performance
// tests.
// TODO(jeremy): Remove once crbug.com/317481 is fixed.
void RecordMainEntryTimeHistogram() {
const int kLowWordMask = 0xFFFFFFFF;
const int kLower31BitsMask = 0x7FFFFFFF;
base::TimeDelta browser_main_entry_time_absolute =
*MainEntryPointTimeInternal() - base::Time::UnixEpoch();
uint64 browser_main_entry_time_raw_ms =
browser_main_entry_time_absolute.InMilliseconds();
base::TimeDelta browser_main_entry_time_raw_ms_high_word =
base::TimeDelta::FromMilliseconds(
(browser_main_entry_time_raw_ms >> 32) & kLowWordMask);
// Shift by one because histograms only support non-negative values.
base::TimeDelta browser_main_entry_time_raw_ms_low_word =
base::TimeDelta::FromMilliseconds(
(browser_main_entry_time_raw_ms >> 1) & kLower31BitsMask);
// A timestamp is a 64 bit value, yet histograms can only store 32 bits.
LOCAL_HISTOGRAM_TIMES("Startup.BrowserMainEntryTimeAbsoluteHighWord",
browser_main_entry_time_raw_ms_high_word);
LOCAL_HISTOGRAM_TIMES("Startup.BrowserMainEntryTimeAbsoluteLowWord",
browser_main_entry_time_raw_ms_low_word);
}
bool g_main_entry_time_was_recorded = false;
// Environment variable that stores the timestamp when the executable's main()
// function was entered.
const char kChromeMainTimeEnvVar[] = "CHROME_MAIN_TIME";
} // namespace
namespace startup_metric_utils {
bool WasNonBrowserUIDisplayed() {
return g_non_browser_ui_displayed;
}
void SetNonBrowserUIDisplayed() {
g_non_browser_ui_displayed = true;
}
void RecordMainEntryPointTime() {
DCHECK(!g_main_entry_time_was_recorded);
g_main_entry_time_was_recorded = true;
MainEntryPointTimeInternal();
}
void RecordExeMainEntryTime() {
std::string exe_load_time =
base::Int64ToString(base::Time::Now().ToInternalValue());
scoped_ptr<base::Environment> env(base::Environment::Create());
env->SetVar(kChromeMainTimeEnvVar, exe_load_time);
}
void RecordSavedMainEntryPointTime(const base::Time& entry_point_time) {
DCHECK(!g_main_entry_time_was_recorded);
g_main_entry_time_was_recorded = true;
*MainEntryPointTimeInternal() = entry_point_time;
}
// Return the time recorded by RecordMainEntryPointTime().
const base::Time MainEntryStartTime() {
DCHECK(g_main_entry_time_was_recorded);
return *MainEntryPointTimeInternal();
}
void OnBrowserStartupComplete(bool is_first_run) {
RecordHardFaultHistogram(is_first_run);
RecordMainEntryTimeHistogram();
// Bail if uptime < 7 minutes, to filter out cases where Chrome may have been
// autostarted and the machine is under io pressure.
const int64 kSevenMinutesInMilliseconds =
base::TimeDelta::FromMinutes(7).InMilliseconds();
if (base::SysInfo::Uptime() < kSevenMinutesInMilliseconds)
return;
// The Startup.BrowserMessageLoopStartTime histogram recorded in
// chrome_browser_main.cc exhibits instability in the field which limits its
// usefulness in all scenarios except when we have a very large sample size.
// Attempt to mitigate this with a new metric:
// * Measure time from main entry rather than the OS' notion of process start
// time.
// * Only measure launches that occur 7 minutes after boot to try to avoid
// cases where Chrome is auto-started and IO is heavily loaded.
base::TimeDelta startup_time_from_main_entry =
base::Time::Now() - MainEntryStartTime();
if (is_first_run) {
UMA_HISTOGRAM_LONG_TIMES(
"Startup.BrowserMessageLoopStartTimeFromMainEntry.FirstRun",
startup_time_from_main_entry);
} else {
UMA_HISTOGRAM_LONG_TIMES(
"Startup.BrowserMessageLoopStartTimeFromMainEntry",
startup_time_from_main_entry);
}
// CurrentProcessInfo::CreationTime() is currently only implemented on some
// platforms.
#if (defined(OS_MACOSX) && !defined(OS_IOS)) || defined(OS_WIN) || \
defined(OS_LINUX)
// Record timings between process creation, the main() in the executable being
// reached and the main() in the shared library being reached.
scoped_ptr<base::Environment> env(base::Environment::Create());
std::string chrome_main_entry_time_string;
if (env->GetVar(kChromeMainTimeEnvVar, &chrome_main_entry_time_string)) {
// The time that the Chrome executable's main() function was entered.
int64 chrome_main_entry_time_int = 0;
if (base::StringToInt64(chrome_main_entry_time_string,
&chrome_main_entry_time_int)) {
base::Time process_create_time = base::CurrentProcessInfo::CreationTime();
base::Time exe_main_time =
base::Time::FromInternalValue(chrome_main_entry_time_int);
base::Time dll_main_time = MainEntryStartTime();
// Process create to chrome.exe:main().
UMA_HISTOGRAM_LONG_TIMES("Startup.LoadTime.ProcessCreateToExeMain",
exe_main_time - process_create_time);
// chrome.exe:main() to chrome.dll:main().
UMA_HISTOGRAM_LONG_TIMES("Startup.LoadTime.ExeMainToDllMain",
dll_main_time - exe_main_time);
// Process create to chrome.dll:main().
UMA_HISTOGRAM_LONG_TIMES("Startup.LoadTime.ProcessCreateToDllMain",
dll_main_time - process_create_time);
}
}
#endif
}
const base::Time* MainEntryPointTime() {
if (!g_main_entry_time_was_recorded)
return NULL;
return MainEntryPointTimeInternal();
}
} // namespace startup_metric_utils
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