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概述

开机阶段描述

阶段	描述
boot_progress_start	系统进入用户空间，标志着kernel启动完成
boot_progress_preload_start	Zygote启动
boot_progress_preload_end	Zygote结束
boot_progress_system_run	SystemServer ready,开始启动Android系统服务，如PMS，APMS等
boot_progress_pms_start	PMS开始扫描安装的应用
boot_progress_pms_system_scan_start	PMS先行扫描/system目录下的安装包
boot_progress_pms_data_scan_start	PMS扫描/data目录下的安装包
boot_progress_pms_scan_end	PMS扫描结束
boot_progress_pms_ready	PMS就绪
boot_progress_ams_ready	AMS就绪
boot_progress_enable_screen	AMS启动完成后开始激活屏幕，从此以后屏幕才能响应用户的触摸，它在WindowManagerService发出退出开机动画的时间节点之前，而真正退出开机动画还会花费少许时间，具体依赖animation zip 包中的desc.txt。wm_boot_animation_done才是用户感知到的动画结束时间节点
sf_stop_bootanim	SF设置service.bootanim.exit属性值为1，标志系统要结束开机动画了，可以用来跟踪开机动画结尾部分消耗的时间
wm_boot_animation_done	开机动画结束，这一步用户能直观感受到开机结束

一、boot_progress_start

frameworks/base/core/jni/AndroidRuntime.cpp

void AndroidRuntime::start(const char* className, const Vector<String8>& options, bool zygote)
{.../** 'startSystemServer == true' means runtime is obsolete and not run from* init.rc anymore, so we print out the boot start event here.*/for (size_t i = 0; i < options.size(); ++i) {if (options[i] == startSystemServer) {primary_zygote = true;/* track our progress through the boot sequence */const int LOG_BOOT_PROGRESS_START = 3000;LOG_EVENT_LONG(LOG_BOOT_PROGRESS_START,  ns2ms(systemTime(SYSTEM_TIME_MONOTONIC)));}}...
}

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二、boot_progress_preload_start

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三、boot_progress_preload_end

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四、boot_progress_system_run

frameworks/base/services/java/com/android/server/SystemServer.java

    private void run() {...// Here we go!Slog.i(TAG, "Entered the Android system server!");final long uptimeMillis = SystemClock.elapsedRealtime();EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_SYSTEM_RUN, uptimeMillis);if (!mRuntimeRestart) {FrameworkStatsLog.write(FrameworkStatsLog.BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,FrameworkStatsLog.BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__SYSTEM_SERVER_INIT_START,uptimeMillis);}...}

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五、boot_progress_pms_start

frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java

    public PackageManagerService(Injector injector, boolean onlyCore, boolean factoryTest) {...mInjector = injector;mInjector.bootstrap(this);mLock = injector.getLock();mInstallLock = injector.getInstallLock();LockGuard.installLock(mLock, LockGuard.INDEX_PACKAGES);EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_START,SystemClock.uptimeMillis());...}

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六、boot_progress_pms_system_scan_start

frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java

    public PackageManagerService(Injector injector, boolean onlyCore, boolean factoryTest) {...long startTime = SystemClock.uptimeMillis();EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_SYSTEM_SCAN_START,startTime);final String bootClassPath = System.getenv("BOOTCLASSPATH");final String systemServerClassPath = System.getenv("SYSTEMSERVERCLASSPATH");if (bootClassPath == null) {Slog.w(TAG, "No BOOTCLASSPATH found!");}if (systemServerClassPath == null) {Slog.w(TAG, "No SYSTEMSERVERCLASSPATH found!");}...}

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七、boot_progress_pms_data_scan_start

frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java

    public PackageManagerService(Injector injector, boolean onlyCore, boolean factoryTest) {...// Remove any shared userIDs that have no associated packagesmSettings.pruneSharedUsersLPw();final long systemScanTime = SystemClock.uptimeMillis() - startTime;final int systemPackagesCount = mPackages.size();Slog.i(TAG, "Finished scanning system apps. Time: " + systemScanTime+ " ms, packageCount: " + systemPackagesCount+ " , timePerPackage: "+ (systemPackagesCount == 0 ? 0 : systemScanTime / systemPackagesCount)+ " , cached: " + cachedSystemApps);if (mIsUpgrade && systemPackagesCount > 0) {//CHECKSTYLE:OFF IndentationCheckFrameworkStatsLog.write(FrameworkStatsLog.BOOT_TIME_EVENT_DURATION_REPORTED,BOOT_TIME_EVENT_DURATION__EVENT__OTA_PACKAGE_MANAGER_SYSTEM_APP_AVG_SCAN_TIME,systemScanTime / systemPackagesCount);//CHECKSTYLE:ON IndentationCheck}if (!mOnlyCore) {EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_DATA_SCAN_START,SystemClock.uptimeMillis());scanDirTracedLI(sAppInstallDir, 0, scanFlags | SCAN_REQUIRE_KNOWN, 0,packageParser, executorService);}...}

八、boot_progress_pms_scan_end

frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java

    public PackageManagerService(Injector injector, boolean onlyCore, boolean factoryTest) {...// Now that we know all the packages we are keeping,// read and update their last usage times.mPackageUsage.read(mSettings.mPackages);mCompilerStats.read();EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_SCAN_END,SystemClock.uptimeMillis());Slog.i(TAG, "Time to scan packages: "+ ((SystemClock.uptimeMillis()-startTime)/1000f)+ " seconds");...}

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九、boot_progress_pms_ready

frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java

    public PackageManagerService(Injector injector, boolean onlyCore, boolean factoryTest) {...// can downgrade to readert.traceBegin("write settings");mSettings.writeLPr();t.traceEnd();EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_READY,SystemClock.uptimeMillis());...}

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十、boot_progress_ams_ready

frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java

    public void systemReady(final Runnable goingCallback, @NonNull TimingsTraceAndSlog t) {...****t.traceEnd(); // KillProcessesSlog.i(TAG, "System now ready");EventLogTags.writeBootProgressAmsReady(SystemClock.uptimeMillis());t.traceBegin("updateTopComponentForFactoryTest");mAtmInternal.updateTopComponentForFactoryTest();t.traceEnd();...}

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十一、boot_progress_enable_screen

frameworks/base/services/core/java/com/android/server/wm/ActivityTaskManagerService.java

        @Overridepublic void enableScreenAfterBoot(boolean booted) {writeBootProgressEnableScreen(SystemClock.uptimeMillis());mWindowManager.enableScreenAfterBoot();synchronized (mGlobalLock) {updateEventDispatchingLocked(booted);}}

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十二、sf_stop_bootanim

frameworks/native/services/surfaceflinger/SurfaceFlinger.cpp

void SurfaceFlinger::bootFinished()
{...// stop boot animation// formerly we would just kill the process, but we now ask it to exit so it// can choose where to stop the animation.property_set("service.bootanim.exit", "1");const int LOGTAG_SF_STOP_BOOTANIM = 60110;LOG_EVENT_LONG(LOGTAG_SF_STOP_BOOTANIM,ns2ms(systemTime(SYSTEM_TIME_MONOTONIC)));sp<IBinder> input(defaultServiceManager()->getService(String16("inputflinger")));...
}

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十三、wm_boot_animation_done

frameworks/base/services/core/java/com/android/server/wm/WindowManagerService.java

    private void performEnableScreen() {...try {IBinder surfaceFlinger = ServiceManager.getService("SurfaceFlinger");if (surfaceFlinger != null) {ProtoLog.i(WM_ERROR, "******* TELLING SURFACE FLINGER WE ARE BOOTED!");Parcel data = Parcel.obtain();data.writeInterfaceToken("android.ui.ISurfaceComposer");surfaceFlinger.transact(IBinder.FIRST_CALL_TRANSACTION, // BOOT_FINISHEDdata, null, 0);data.recycle();}} catch (RemoteException ex) {ProtoLog.e(WM_ERROR, "Boot completed: SurfaceFlinger is dead!");}EventLogTags.writeWmBootAnimationDone(SystemClock.uptimeMillis());Trace.asyncTraceEnd(TRACE_TAG_WINDOW_MANAGER, "Stop bootanim", 0);mDisplayEnabled = true;ProtoLog.i(WM_DEBUG_SCREEN_ON, "******************** ENABLING SCREEN!");...}

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整体框架