bootstat/bootstat.cpp - platform/system/core - Gitiles

 /*
  * Copyright (C) 2016 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 // The bootstat command provides options to persist boot events with the current
 // timestamp, dump the persisted events, and log all events to EventLog to be
 // uploaded to Android log storage via Tron.

 #include <getopt.h>
 #include <unistd.h>

 #include <chrono>
 #include <cmath>
 #include <cstddef>
 #include <cstdio>
 #include <ctime>
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>

 #include <android-base/chrono_utils.h>
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
 #include <android-base/strings.h>
 #include <android/log.h>
 #include <cutils/properties.h>
 #include <metricslogger/metrics_logger.h>

 #include "boot_event_record_store.h"

 namespace {

 // Scans the boot event record store for record files and logs each boot event
 // via EventLog.
 void LogBootEvents() {
   BootEventRecordStore boot_event_store;

   auto events = boot_event_store.GetAllBootEvents();
   for (auto i = events.cbegin(); i != events.cend(); ++i) {
     android::metricslogger::LogHistogram(i->first, i->second);
   }
 }

 // Records the named boot |event| to the record store. If |value| is non-empty
 // and is a proper string representation of an integer value, the converted
 // integer value is associated with the boot event.
 void RecordBootEventFromCommandLine(
     const std::string& event, const std::string& value_str) {
   BootEventRecordStore boot_event_store;
   if (!value_str.empty()) {
     int32_t value = 0;
     if (android::base::ParseInt(value_str, &value)) {
       boot_event_store.AddBootEventWithValue(event, value);
     }
   } else {
     boot_event_store.AddBootEvent(event);
   }
 }

 void PrintBootEvents() {
   printf("Boot events:\n");
   printf("------------\n");

   BootEventRecordStore boot_event_store;
   auto events = boot_event_store.GetAllBootEvents();
   for (auto i = events.cbegin(); i != events.cend(); ++i) {
     printf("%s\t%d\n", i->first.c_str(), i->second);
   }
 }

 void ShowHelp(const char *cmd) {
   fprintf(stderr, "Usage: %s [options]\n", cmd);
   fprintf(stderr,
           "options include:\n"
           "  -h, --help              Show this help\n"
           "  -l, --log               Log all metrics to logstorage\n"
           "  -p, --print             Dump the boot event records to the console\n"
           "  -r, --record            Record the timestamp of a named boot event\n"
           "  --value                 Optional value to associate with the boot event\n"
           "  --record_boot_complete  Record metrics related to the time for the device boot\n"
           "  --record_boot_reason    Record the reason why the device booted\n"
           "  --record_time_since_factory_reset Record the time since the device was reset\n");
 }

 // Constructs a readable, printable string from the givencommand line
 // arguments.
 std::string GetCommandLine(int argc, char **argv) {
   std::string cmd;
   for (int i = 0; i < argc; ++i) {
     cmd += argv[i];
     cmd += " ";
   }

   return cmd;
 }

 // Convenience wrapper over the property API that returns an
 // std::string.
 std::string GetProperty(const char* key) {
   std::vector<char> temp(PROPERTY_VALUE_MAX);
   const int len = property_get(key, &temp[0], nullptr);
   if (len < 0) {
     return "";
   }
   return std::string(&temp[0], len);
 }

 constexpr int32_t kUnknownBootReason = 1;

 // A mapping from boot reason string, as read from the ro.boot.bootreason
 // system property, to a unique integer ID. Viewers of log data dashboards for
 // the boot_reason metric may refer to this mapping to discern the histogram
 // values.
 const std::map<std::string, int32_t> kBootReasonMap = {
   {"unknown", kUnknownBootReason},
   {"normal", 2},
   {"recovery", 3},
   {"reboot", 4},
   {"PowerKey", 5},
   {"hard_reset", 6},
   {"kernel_panic", 7},
   {"rpm_err", 8},
   {"hw_reset", 9},
   {"tz_err", 10},
   {"adsp_err", 11},
   {"modem_err", 12},
   {"mba_err", 13},
   {"Watchdog", 14},
   {"Panic", 15},
   {"power_key", 16},
   {"power_on", 17},
   {"Reboot", 18},
   {"rtc", 19},
   {"edl", 20},
   {"oem_pon1", 21},
   {"oem_powerkey", 22},
   {"oem_unknown_reset", 23},
   {"srto: HWWDT reset SC", 24},
   {"srto: HWWDT reset platform", 25},
   {"srto: bootloader", 26},
   {"srto: kernel panic", 27},
   {"srto: kernel watchdog reset", 28},
   {"srto: normal", 29},
   {"srto: reboot", 30},
   {"srto: reboot-bootloader", 31},
   {"srto: security watchdog reset", 32},
   {"srto: wakesrc", 33},
   {"srto: watchdog", 34},
   {"srto:1-1", 35},
   {"srto:omap_hsmm", 36},
   {"srto:phy0", 37},
   {"srto:rtc0", 38},
   {"srto:touchpad", 39},
   {"watchdog", 40},
   {"watchdogr", 41},
   {"wdog_bark", 42},
   {"wdog_bite", 43},
   {"wdog_reset", 44},
   {"shutdown,", 45},  // Trailing comma is intentional.
   {"shutdown,userrequested", 46},
   {"reboot,bootloader", 47},
   {"reboot,cold", 48},
   {"reboot,recovery", 49},
   {"thermal_shutdown", 50},
   {"s3_wakeup", 51}
 };

 // Converts a string value representing the reason the system booted to an
 // integer representation. This is necessary for logging the boot_reason metric
 // via Tron, which does not accept non-integer buckets in histograms.
 int32_t BootReasonStrToEnum(const std::string& boot_reason) {
   auto mapping = kBootReasonMap.find(boot_reason);
   if (mapping != kBootReasonMap.end()) {
     return mapping->second;
   }

   LOG(INFO) << "Unknown boot reason: " << boot_reason;
   return kUnknownBootReason;
 }

 // Returns the appropriate metric key prefix for the boot_complete metric such
 // that boot metrics after a system update are labeled as ota_boot_complete;
 // otherwise, they are labeled as boot_complete.  This method encapsulates the
 // bookkeeping required to track when a system update has occurred by storing
 // the UTC timestamp of the system build date and comparing against the current
 // system build date.
 std::string CalculateBootCompletePrefix() {
   static const std::string kBuildDateKey = "build_date";
   std::string boot_complete_prefix = "boot_complete";

   std::string build_date_str = GetProperty("ro.build.date.utc");
   int32_t build_date;
   if (!android::base::ParseInt(build_date_str, &build_date)) {
     return std::string();
   }

   BootEventRecordStore boot_event_store;
   BootEventRecordStore::BootEventRecord record;
   if (!boot_event_store.GetBootEvent(kBuildDateKey, &record)) {
     boot_complete_prefix = "factory_reset_" + boot_complete_prefix;
     boot_event_store.AddBootEventWithValue(kBuildDateKey, build_date);
   } else if (build_date != record.second) {
     boot_complete_prefix = "ota_" + boot_complete_prefix;
     boot_event_store.AddBootEventWithValue(kBuildDateKey, build_date);
   }

   return boot_complete_prefix;
 }

 // Records the value of a given ro.boottime.init property in milliseconds.
 void RecordInitBootTimeProp(
     BootEventRecordStore* boot_event_store, const char* property) {
   std::string value = GetProperty(property);

   int32_t time_in_ms;
   if (android::base::ParseInt(value, &time_in_ms)) {
     boot_event_store->AddBootEventWithValue(property, time_in_ms);
   }
 }

 // A map from bootloader timing stage to the time that stage took during boot.
 typedef std::map<std::string, int32_t> BootloaderTimingMap;

 // Returns a mapping from bootloader stage names to the time those stages
 // took to boot.
 const BootloaderTimingMap GetBootLoaderTimings() {
   BootloaderTimingMap timings;

   // |ro.boot.boottime| is of the form 'stage1:time1,...,stageN:timeN',
   // where timeN is in milliseconds.
   std::string value = GetProperty("ro.boot.boottime");
   if (value.empty()) {
     // ro.boot.boottime is not reported on all devices.
     return BootloaderTimingMap();
   }

   auto stages = android::base::Split(value, ",");
   for (const auto& stageTiming : stages) {
     // |stageTiming| is of the form 'stage:time'.
     auto stageTimingValues = android::base::Split(stageTiming, ":");
     DCHECK_EQ(2U, stageTimingValues.size());

     std::string stageName = stageTimingValues[0];
     int32_t time_ms;
     if (android::base::ParseInt(stageTimingValues[1], &time_ms)) {
       timings[stageName] = time_ms;
     }
   }

   return timings;
 }

 // Parses and records the set of bootloader stages and associated boot times
 // from the ro.boot.boottime system property.
 void RecordBootloaderTimings(BootEventRecordStore* boot_event_store,
                              const BootloaderTimingMap& bootloader_timings) {
   int32_t total_time = 0;
   for (const auto& timing : bootloader_timings) {
     total_time += timing.second;
     boot_event_store->AddBootEventWithValue("boottime.bootloader." + timing.first, timing.second);
   }

   boot_event_store->AddBootEventWithValue("boottime.bootloader.total", total_time);
 }

 // Records the closest estimation to the absolute device boot time, i.e.,
 // from power on to boot_complete, including bootloader times.
 void RecordAbsoluteBootTime(BootEventRecordStore* boot_event_store,
                             const BootloaderTimingMap& bootloader_timings,
                             std::chrono::milliseconds uptime) {
   int32_t bootloader_time_ms = 0;

   for (const auto& timing : bootloader_timings) {
     if (timing.first.compare("SW") != 0) {
       bootloader_time_ms += timing.second;
     }
   }

   auto bootloader_duration = std::chrono::milliseconds(bootloader_time_ms);
   auto absolute_total =
       std::chrono::duration_cast<std::chrono::seconds>(bootloader_duration + uptime);
   boot_event_store->AddBootEventWithValue("absolute_boot_time", absolute_total.count());
 }

 // Records several metrics related to the time it takes to boot the device,
 // including disambiguating boot time on encrypted or non-encrypted devices.
 void RecordBootComplete() {
   BootEventRecordStore boot_event_store;
   BootEventRecordStore::BootEventRecord record;

   auto time_since_epoch = android::base::boot_clock::now().time_since_epoch();
   auto uptime = std::chrono::duration_cast<std::chrono::seconds>(time_since_epoch);
   time_t current_time_utc = time(nullptr);

   if (boot_event_store.GetBootEvent("last_boot_time_utc", &record)) {
     time_t last_boot_time_utc = record.second;
     time_t time_since_last_boot = difftime(current_time_utc,
                                            last_boot_time_utc);
     boot_event_store.AddBootEventWithValue("time_since_last_boot",
                                            time_since_last_boot);
   }

   boot_event_store.AddBootEventWithValue("last_boot_time_utc", current_time_utc);

   // The boot_complete metric has two variants: boot_complete and
   // ota_boot_complete.  The latter signifies that the device is booting after
   // a system update.
   std::string boot_complete_prefix = CalculateBootCompletePrefix();
   if (boot_complete_prefix.empty()) {
     // The system is hosed because the build date property could not be read.
     return;
   }

   // post_decrypt_time_elapsed is only logged on encrypted devices.
   if (boot_event_store.GetBootEvent("post_decrypt_time_elapsed", &record)) {
     // Log the amount of time elapsed until the device is decrypted, which
     // includes the variable amount of time the user takes to enter the
     // decryption password.
     boot_event_store.AddBootEventWithValue("boot_decryption_complete", uptime.count());

     // Subtract the decryption time to normalize the boot cycle timing.
     std::chrono::seconds boot_complete = std::chrono::seconds(uptime.count() - record.second);
     boot_event_store.AddBootEventWithValue(boot_complete_prefix + "_post_decrypt",
                                            boot_complete.count());
   } else {
       boot_event_store.AddBootEventWithValue(boot_complete_prefix + "_no_encryption",
                                              uptime.count());
   }

   // Record the total time from device startup to boot complete, regardless of
   // encryption state.
   boot_event_store.AddBootEventWithValue(boot_complete_prefix, uptime.count());

   RecordInitBootTimeProp(&boot_event_store, "ro.boottime.init");
   RecordInitBootTimeProp(&boot_event_store, "ro.boottime.init.selinux");
   RecordInitBootTimeProp(&boot_event_store, "ro.boottime.init.cold_boot_wait");

   const BootloaderTimingMap bootloader_timings = GetBootLoaderTimings();
   RecordBootloaderTimings(&boot_event_store, bootloader_timings);

   auto uptime_ms = std::chrono::duration_cast<std::chrono::milliseconds>(time_since_epoch);
   RecordAbsoluteBootTime(&boot_event_store, bootloader_timings, uptime_ms);
 }

 // Records the boot_reason metric by querying the ro.boot.bootreason system
 // property.
 void RecordBootReason() {
   int32_t boot_reason = BootReasonStrToEnum(GetProperty("ro.boot.bootreason"));
   BootEventRecordStore boot_event_store;
   boot_event_store.AddBootEventWithValue("boot_reason", boot_reason);
 }

 // Records two metrics related to the user resetting a device: the time at
 // which the device is reset, and the time since the user last reset the
 // device.  The former is only set once per-factory reset.
 void RecordFactoryReset() {
   BootEventRecordStore boot_event_store;
   BootEventRecordStore::BootEventRecord record;

   time_t current_time_utc = time(nullptr);

   if (current_time_utc < 0) {
     // UMA does not display negative values in buckets, so convert to positive.
     android::metricslogger::LogHistogram(
         "factory_reset_current_time_failure", std::abs(current_time_utc));

     // Logging via BootEventRecordStore to see if using android::metricslogger::LogHistogram
     // is losing records somehow.
     boot_event_store.AddBootEventWithValue(
         "factory_reset_current_time_failure", std::abs(current_time_utc));
     return;
   } else {
     android::metricslogger::LogHistogram("factory_reset_current_time", current_time_utc);

     // Logging via BootEventRecordStore to see if using android::metricslogger::LogHistogram
     // is losing records somehow.
     boot_event_store.AddBootEventWithValue(
         "factory_reset_current_time", current_time_utc);
   }

   // The factory_reset boot event does not exist after the device is reset, so
   // use this signal to mark the time of the factory reset.
   if (!boot_event_store.GetBootEvent("factory_reset", &record)) {
     boot_event_store.AddBootEventWithValue("factory_reset", current_time_utc);

     // Don't log the time_since_factory_reset until some time has elapsed.
     // The data is not meaningful yet and skews the histogram buckets.
     return;
   }

   // Calculate and record the difference in time between now and the
   // factory_reset time.
   time_t factory_reset_utc = record.second;
   android::metricslogger::LogHistogram("factory_reset_record_value", factory_reset_utc);

   // Logging via BootEventRecordStore to see if using android::metricslogger::LogHistogram
   // is losing records somehow.
   boot_event_store.AddBootEventWithValue(
       "factory_reset_record_value", factory_reset_utc);

   time_t time_since_factory_reset = difftime(current_time_utc,
                                              factory_reset_utc);
   boot_event_store.AddBootEventWithValue("time_since_factory_reset",
                                          time_since_factory_reset);
 }

 }  // namespace

 int main(int argc, char **argv) {
   android::base::InitLogging(argv);

   const std::string cmd_line = GetCommandLine(argc, argv);
   LOG(INFO) << "Service started: " << cmd_line;

   int option_index = 0;
   static const char value_str[] = "value";
   static const char boot_complete_str[] = "record_boot_complete";
   static const char boot_reason_str[] = "record_boot_reason";
   static const char factory_reset_str[] = "record_time_since_factory_reset";
   static const struct option long_options[] = {
     { "help",            no_argument,       NULL,   'h' },
     { "log",             no_argument,       NULL,   'l' },
     { "print",           no_argument,       NULL,   'p' },
     { "record",          required_argument, NULL,   'r' },
     { value_str,         required_argument, NULL,   0 },
     { boot_complete_str, no_argument,       NULL,   0 },
     { boot_reason_str,   no_argument,       NULL,   0 },
     { factory_reset_str, no_argument,       NULL,   0 },
     { NULL,              0,                 NULL,   0 }
   };

   std::string boot_event;
   std::string value;
   int opt = 0;
   while ((opt = getopt_long(argc, argv, "hlpr:", long_options, &option_index)) != -1) {
     switch (opt) {
       // This case handles long options which have no single-character mapping.
       case 0: {
         const std::string option_name = long_options[option_index].name;
         if (option_name == value_str) {
           // |optarg| is an external variable set by getopt representing
           // the option argument.
           value = optarg;
         } else if (option_name == boot_complete_str) {
           RecordBootComplete();
         } else if (option_name == boot_reason_str) {
           RecordBootReason();
         } else if (option_name == factory_reset_str) {
           RecordFactoryReset();
         } else {
           LOG(ERROR) << "Invalid option: " << option_name;
         }
         break;
       }

       case 'h': {
         ShowHelp(argv[0]);
         break;
       }

       case 'l': {
         LogBootEvents();
         break;
       }

       case 'p': {
         PrintBootEvents();
         break;
       }

       case 'r': {
         // |optarg| is an external variable set by getopt representing
         // the option argument.
         boot_event = optarg;
         break;
       }

       default: {
         DCHECK_EQ(opt, '?');

         // |optopt| is an external variable set by getopt representing
         // the value of the invalid option.
         LOG(ERROR) << "Invalid option: " << optopt;
         ShowHelp(argv[0]);
         return EXIT_FAILURE;
       }
     }
   }

   if (!boot_event.empty()) {
     RecordBootEventFromCommandLine(boot_event, value);
   }

   return 0;
 }
	/*
	* Copyright (C) 2016 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	// The bootstat command provides options to persist boot events with the current
	// timestamp, dump the persisted events, and log all events to EventLog to be
	// uploaded to Android log storage via Tron.

	#include <getopt.h>
	#include <unistd.h>

	#include <chrono>
	#include <cmath>
	#include <cstddef>
	#include <cstdio>
	#include <ctime>
	#include <map>
	#include <memory>
	#include <string>
	#include <vector>

	#include <android-base/chrono_utils.h>
	#include <android-base/logging.h>
	#include <android-base/parseint.h>
	#include <android-base/strings.h>
	#include <android/log.h>
	#include <cutils/properties.h>
	#include <metricslogger/metrics_logger.h>

	#include "boot_event_record_store.h"

	namespace {

	// Scans the boot event record store for record files and logs each boot event
	// via EventLog.
	void LogBootEvents() {
	BootEventRecordStore boot_event_store;

	auto events = boot_event_store.GetAllBootEvents();
	for (auto i = events.cbegin(); i != events.cend(); ++i) {
	android::metricslogger::LogHistogram(i->first, i->second);
	}
	}

	// Records the named boot \|event\| to the record store. If \|value\| is non-empty
	// and is a proper string representation of an integer value, the converted
	// integer value is associated with the boot event.
	void RecordBootEventFromCommandLine(
	const std::string& event, const std::string& value_str) {
	BootEventRecordStore boot_event_store;
	if (!value_str.empty()) {
	int32_t value = 0;
	if (android::base::ParseInt(value_str, &value)) {
	boot_event_store.AddBootEventWithValue(event, value);
	}
	} else {
	boot_event_store.AddBootEvent(event);
	}
	}

	void PrintBootEvents() {
	printf("Boot events:\n");
	printf("------------\n");

	BootEventRecordStore boot_event_store;
	auto events = boot_event_store.GetAllBootEvents();
	for (auto i = events.cbegin(); i != events.cend(); ++i) {
	printf("%s\t%d\n", i->first.c_str(), i->second);
	}
	}

	void ShowHelp(const char *cmd) {
	fprintf(stderr, "Usage: %s [options]\n", cmd);
	fprintf(stderr,
	"options include:\n"
	" -h, --help Show this help\n"
	" -l, --log Log all metrics to logstorage\n"
	" -p, --print Dump the boot event records to the console\n"
	" -r, --record Record the timestamp of a named boot event\n"
	" --value Optional value to associate with the boot event\n"
	" --record_boot_complete Record metrics related to the time for the device boot\n"
	" --record_boot_reason Record the reason why the device booted\n"
	" --record_time_since_factory_reset Record the time since the device was reset\n");
	}

	// Constructs a readable, printable string from the givencommand line
	// arguments.
	std::string GetCommandLine(int argc, char **argv) {
	std::string cmd;
	for (int i = 0; i < argc; ++i) {
	cmd += argv[i];
	cmd += " ";
	}

	return cmd;
	}

	// Convenience wrapper over the property API that returns an
	// std::string.
	std::string GetProperty(const char* key) {
	std::vector<char> temp(PROPERTY_VALUE_MAX);
	const int len = property_get(key, &temp[0], nullptr);
	if (len < 0) {
	return "";
	}
	return std::string(&temp[0], len);
	}

	constexpr int32_t kUnknownBootReason = 1;

	// A mapping from boot reason string, as read from the ro.boot.bootreason
	// system property, to a unique integer ID. Viewers of log data dashboards for
	// the boot_reason metric may refer to this mapping to discern the histogram
	// values.
	const std::map<std::string, int32_t> kBootReasonMap = {
	{"unknown", kUnknownBootReason},
	{"normal", 2},
	{"recovery", 3},
	{"reboot", 4},
	{"PowerKey", 5},
	{"hard_reset", 6},
	{"kernel_panic", 7},
	{"rpm_err", 8},
	{"hw_reset", 9},
	{"tz_err", 10},
	{"adsp_err", 11},
	{"modem_err", 12},
	{"mba_err", 13},
	{"Watchdog", 14},
	{"Panic", 15},
	{"power_key", 16},
	{"power_on", 17},
	{"Reboot", 18},
	{"rtc", 19},
	{"edl", 20},
	{"oem_pon1", 21},
	{"oem_powerkey", 22},
	{"oem_unknown_reset", 23},
	{"srto: HWWDT reset SC", 24},
	{"srto: HWWDT reset platform", 25},
	{"srto: bootloader", 26},
	{"srto: kernel panic", 27},
	{"srto: kernel watchdog reset", 28},
	{"srto: normal", 29},
	{"srto: reboot", 30},
	{"srto: reboot-bootloader", 31},
	{"srto: security watchdog reset", 32},
	{"srto: wakesrc", 33},
	{"srto: watchdog", 34},
	{"srto:1-1", 35},
	{"srto:omap_hsmm", 36},
	{"srto:phy0", 37},
	{"srto:rtc0", 38},
	{"srto:touchpad", 39},
	{"watchdog", 40},
	{"watchdogr", 41},
	{"wdog_bark", 42},
	{"wdog_bite", 43},
	{"wdog_reset", 44},
	{"shutdown,", 45}, // Trailing comma is intentional.
	{"shutdown,userrequested", 46},
	{"reboot,bootloader", 47},
	{"reboot,cold", 48},
	{"reboot,recovery", 49},
	{"thermal_shutdown", 50},
	{"s3_wakeup", 51}
	};

	// Converts a string value representing the reason the system booted to an
	// integer representation. This is necessary for logging the boot_reason metric
	// via Tron, which does not accept non-integer buckets in histograms.
	int32_t BootReasonStrToEnum(const std::string& boot_reason) {
	auto mapping = kBootReasonMap.find(boot_reason);
	if (mapping != kBootReasonMap.end()) {
	return mapping->second;
	}

	LOG(INFO) << "Unknown boot reason: " << boot_reason;
	return kUnknownBootReason;
	}

	// Returns the appropriate metric key prefix for the boot_complete metric such
	// that boot metrics after a system update are labeled as ota_boot_complete;
	// otherwise, they are labeled as boot_complete. This method encapsulates the
	// bookkeeping required to track when a system update has occurred by storing
	// the UTC timestamp of the system build date and comparing against the current
	// system build date.
	std::string CalculateBootCompletePrefix() {
	static const std::string kBuildDateKey = "build_date";
	std::string boot_complete_prefix = "boot_complete";

	std::string build_date_str = GetProperty("ro.build.date.utc");
	int32_t build_date;
	if (!android::base::ParseInt(build_date_str, &build_date)) {
	return std::string();
	}

	BootEventRecordStore boot_event_store;
	BootEventRecordStore::BootEventRecord record;
	if (!boot_event_store.GetBootEvent(kBuildDateKey, &record)) {
	boot_complete_prefix = "factory_reset_" + boot_complete_prefix;
	boot_event_store.AddBootEventWithValue(kBuildDateKey, build_date);
	} else if (build_date != record.second) {
	boot_complete_prefix = "ota_" + boot_complete_prefix;
	boot_event_store.AddBootEventWithValue(kBuildDateKey, build_date);
	}

	return boot_complete_prefix;
	}

	// Records the value of a given ro.boottime.init property in milliseconds.
	void RecordInitBootTimeProp(
	BootEventRecordStore* boot_event_store, const char* property) {
	std::string value = GetProperty(property);

	int32_t time_in_ms;
	if (android::base::ParseInt(value, &time_in_ms)) {
	boot_event_store->AddBootEventWithValue(property, time_in_ms);
	}
	}

	// A map from bootloader timing stage to the time that stage took during boot.
	typedef std::map<std::string, int32_t> BootloaderTimingMap;

	// Returns a mapping from bootloader stage names to the time those stages
	// took to boot.
	const BootloaderTimingMap GetBootLoaderTimings() {
	BootloaderTimingMap timings;

	// \|ro.boot.boottime\| is of the form 'stage1:time1,...,stageN:timeN',
	// where timeN is in milliseconds.
	std::string value = GetProperty("ro.boot.boottime");
	if (value.empty()) {
	// ro.boot.boottime is not reported on all devices.
	return BootloaderTimingMap();
	}

	auto stages = android::base::Split(value, ",");
	for (const auto& stageTiming : stages) {
	// \|stageTiming\| is of the form 'stage:time'.
	auto stageTimingValues = android::base::Split(stageTiming, ":");
	DCHECK_EQ(2U, stageTimingValues.size());

	std::string stageName = stageTimingValues[0];
	int32_t time_ms;
	if (android::base::ParseInt(stageTimingValues[1], &time_ms)) {
	timings[stageName] = time_ms;
	}
	}

	return timings;
	}

	// Parses and records the set of bootloader stages and associated boot times
	// from the ro.boot.boottime system property.
	void RecordBootloaderTimings(BootEventRecordStore* boot_event_store,
	const BootloaderTimingMap& bootloader_timings) {
	int32_t total_time = 0;
	for (const auto& timing : bootloader_timings) {
	total_time += timing.second;
	boot_event_store->AddBootEventWithValue("boottime.bootloader." + timing.first, timing.second);
	}

	boot_event_store->AddBootEventWithValue("boottime.bootloader.total", total_time);
	}

	// Records the closest estimation to the absolute device boot time, i.e.,
	// from power on to boot_complete, including bootloader times.
	void RecordAbsoluteBootTime(BootEventRecordStore* boot_event_store,
	const BootloaderTimingMap& bootloader_timings,
	std::chrono::milliseconds uptime) {
	int32_t bootloader_time_ms = 0;

	for (const auto& timing : bootloader_timings) {
	if (timing.first.compare("SW") != 0) {
	bootloader_time_ms += timing.second;
	}
	}

	auto bootloader_duration = std::chrono::milliseconds(bootloader_time_ms);
	auto absolute_total =
	std::chrono::duration_cast<std::chrono::seconds>(bootloader_duration + uptime);
	boot_event_store->AddBootEventWithValue("absolute_boot_time", absolute_total.count());
	}

	// Records several metrics related to the time it takes to boot the device,
	// including disambiguating boot time on encrypted or non-encrypted devices.
	void RecordBootComplete() {
	BootEventRecordStore boot_event_store;
	BootEventRecordStore::BootEventRecord record;

	auto time_since_epoch = android::base::boot_clock::now().time_since_epoch();
	auto uptime = std::chrono::duration_cast<std::chrono::seconds>(time_since_epoch);
	time_t current_time_utc = time(nullptr);

	if (boot_event_store.GetBootEvent("last_boot_time_utc", &record)) {
	time_t last_boot_time_utc = record.second;
	time_t time_since_last_boot = difftime(current_time_utc,
	last_boot_time_utc);
	boot_event_store.AddBootEventWithValue("time_since_last_boot",
	time_since_last_boot);
	}

	boot_event_store.AddBootEventWithValue("last_boot_time_utc", current_time_utc);

	// The boot_complete metric has two variants: boot_complete and
	// ota_boot_complete. The latter signifies that the device is booting after
	// a system update.
	std::string boot_complete_prefix = CalculateBootCompletePrefix();
	if (boot_complete_prefix.empty()) {
	// The system is hosed because the build date property could not be read.
	return;
	}

	// post_decrypt_time_elapsed is only logged on encrypted devices.
	if (boot_event_store.GetBootEvent("post_decrypt_time_elapsed", &record)) {
	// Log the amount of time elapsed until the device is decrypted, which
	// includes the variable amount of time the user takes to enter the
	// decryption password.
	boot_event_store.AddBootEventWithValue("boot_decryption_complete", uptime.count());

	// Subtract the decryption time to normalize the boot cycle timing.
	std::chrono::seconds boot_complete = std::chrono::seconds(uptime.count() - record.second);
	boot_event_store.AddBootEventWithValue(boot_complete_prefix + "_post_decrypt",
	boot_complete.count());
	} else {
	boot_event_store.AddBootEventWithValue(boot_complete_prefix + "_no_encryption",
	uptime.count());
	}

	// Record the total time from device startup to boot complete, regardless of
	// encryption state.
	boot_event_store.AddBootEventWithValue(boot_complete_prefix, uptime.count());

	RecordInitBootTimeProp(&boot_event_store, "ro.boottime.init");
	RecordInitBootTimeProp(&boot_event_store, "ro.boottime.init.selinux");
	RecordInitBootTimeProp(&boot_event_store, "ro.boottime.init.cold_boot_wait");

	const BootloaderTimingMap bootloader_timings = GetBootLoaderTimings();
	RecordBootloaderTimings(&boot_event_store, bootloader_timings);

	auto uptime_ms = std::chrono::duration_cast<std::chrono::milliseconds>(time_since_epoch);
	RecordAbsoluteBootTime(&boot_event_store, bootloader_timings, uptime_ms);
	}

	// Records the boot_reason metric by querying the ro.boot.bootreason system
	// property.
	void RecordBootReason() {
	int32_t boot_reason = BootReasonStrToEnum(GetProperty("ro.boot.bootreason"));
	BootEventRecordStore boot_event_store;
	boot_event_store.AddBootEventWithValue("boot_reason", boot_reason);
	}

	// Records two metrics related to the user resetting a device: the time at
	// which the device is reset, and the time since the user last reset the
	// device. The former is only set once per-factory reset.
	void RecordFactoryReset() {
	BootEventRecordStore boot_event_store;
	BootEventRecordStore::BootEventRecord record;

	time_t current_time_utc = time(nullptr);

	if (current_time_utc < 0) {
	// UMA does not display negative values in buckets, so convert to positive.
	android::metricslogger::LogHistogram(
	"factory_reset_current_time_failure", std::abs(current_time_utc));

	// Logging via BootEventRecordStore to see if using android::metricslogger::LogHistogram
	// is losing records somehow.
	boot_event_store.AddBootEventWithValue(
	"factory_reset_current_time_failure", std::abs(current_time_utc));
	return;
	} else {
	android::metricslogger::LogHistogram("factory_reset_current_time", current_time_utc);

	// Logging via BootEventRecordStore to see if using android::metricslogger::LogHistogram
	// is losing records somehow.
	boot_event_store.AddBootEventWithValue(
	"factory_reset_current_time", current_time_utc);
	}

	// The factory_reset boot event does not exist after the device is reset, so
	// use this signal to mark the time of the factory reset.
	if (!boot_event_store.GetBootEvent("factory_reset", &record)) {
	boot_event_store.AddBootEventWithValue("factory_reset", current_time_utc);

	// Don't log the time_since_factory_reset until some time has elapsed.
	// The data is not meaningful yet and skews the histogram buckets.
	return;
	}

	// Calculate and record the difference in time between now and the
	// factory_reset time.
	time_t factory_reset_utc = record.second;
	android::metricslogger::LogHistogram("factory_reset_record_value", factory_reset_utc);

	// Logging via BootEventRecordStore to see if using android::metricslogger::LogHistogram
	// is losing records somehow.
	boot_event_store.AddBootEventWithValue(
	"factory_reset_record_value", factory_reset_utc);

	time_t time_since_factory_reset = difftime(current_time_utc,
	factory_reset_utc);
	boot_event_store.AddBootEventWithValue("time_since_factory_reset",
	time_since_factory_reset);
	}

	} // namespace

	int main(int argc, char **argv) {
	android::base::InitLogging(argv);

	const std::string cmd_line = GetCommandLine(argc, argv);
	LOG(INFO) << "Service started: " << cmd_line;

	int option_index = 0;
	static const char value_str[] = "value";
	static const char boot_complete_str[] = "record_boot_complete";
	static const char boot_reason_str[] = "record_boot_reason";
	static const char factory_reset_str[] = "record_time_since_factory_reset";
	static const struct option long_options[] = {
	{ "help", no_argument, NULL, 'h' },
	{ "log", no_argument, NULL, 'l' },
	{ "print", no_argument, NULL, 'p' },
	{ "record", required_argument, NULL, 'r' },
	{ value_str, required_argument, NULL, 0 },
	{ boot_complete_str, no_argument, NULL, 0 },
	{ boot_reason_str, no_argument, NULL, 0 },
	{ factory_reset_str, no_argument, NULL, 0 },
	{ NULL, 0, NULL, 0 }
	};

	std::string boot_event;
	std::string value;
	int opt = 0;
	while ((opt = getopt_long(argc, argv, "hlpr:", long_options, &option_index)) != -1) {
	switch (opt) {
	// This case handles long options which have no single-character mapping.
	case 0: {
	const std::string option_name = long_options[option_index].name;
	if (option_name == value_str) {
	// \|optarg\| is an external variable set by getopt representing
	// the option argument.
	value = optarg;
	} else if (option_name == boot_complete_str) {
	RecordBootComplete();
	} else if (option_name == boot_reason_str) {
	RecordBootReason();
	} else if (option_name == factory_reset_str) {
	RecordFactoryReset();
	} else {
	LOG(ERROR) << "Invalid option: " << option_name;
	}
	break;
	}

	case 'h': {
	ShowHelp(argv[0]);
	break;
	}

	case 'l': {
	LogBootEvents();
	break;
	}

	case 'p': {
	PrintBootEvents();
	break;
	}

	case 'r': {
	// \|optarg\| is an external variable set by getopt representing
	// the option argument.
	boot_event = optarg;
	break;
	}

	default: {
	DCHECK_EQ(opt, '?');

	// \|optopt\| is an external variable set by getopt representing
	// the value of the invalid option.
	LOG(ERROR) << "Invalid option: " << optopt;
	ShowHelp(argv[0]);
	return EXIT_FAILURE;
	}
	}
	}

	if (!boot_event.empty()) {
	RecordBootEventFromCommandLine(boot_event, value);
	}

	return 0;
	}