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systemserver探究筆記



其實一開始本來打算寫Activity啟動的,後來發現自己老是弄不明白AMS與ActivityThread調用關系,于是再往上深究,發現是自己的基礎沒打好,缺少對Android整體的認知,是以才會知其然而不知其是以然。在講system之前先上一張Android整體架構圖。

分析的時候參考了http://quanminchaoren.iteye.com/blog/1252322不過它釋出文章的版本大概還在Android2.2左右 ,源碼可能會有一些出入

systemserver探究筆記

systemserver實際上不是一個server,源碼中也可以看出

public final class SystemServer

當daivik虛拟機啟動的時候,調用了

    public static void main(String[] args) {

        new SystemServer().run();

    }

而在run方法完成了這麼幾件事

1.檢查裝置的時間是不是在1970以後,如果不是的話程式有可能crash掉

2.建立主Thread并循環looper

3.加載Android_server   loadLibrary

4.初始化各種服務

5.初始化systemcontext

6.将systemcontext作為參數建立SystemServiceManager,并以鍵值對的形式存儲到LocalServices

7.開啟各種服務

源碼如下

    private void run() {

        // If a device's clock is before 1970 (before 0), a lot of

        // APIs crash dealing with negative numbers, notably

        // java.io.File#setLastModified, so instead we fake it and

        // hope that time from cell towers or NTP fixes it shortly.

        //檢查系統時間,要是在1970年之前,許多API會crash掉,是以我們希望程式一會通過信号塔或者NTP來修複它

        if (System.currentTimeMillis() < EARLIEST_SUPPORTED_TIME) {

            Slog.w(TAG, "System clock is before 1970; setting to 1970.");

            SystemClock.setCurrentTimeMillis(EARLIEST_SUPPORTED_TIME);

        }

        // Here we go!

        Slog.i(TAG, "Entered the Android system server!");

        EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_SYSTEM_RUN, SystemClock.uptimeMillis());

        // In case the runtime switched since last boot (such as when

        // the old runtime was removed in an OTA), set the system

        // property so that it is in sync. We can't do this in

        // libnativehelper's JniInvocation::Init code where we already

        // had to fallback to a different runtime because it is

        // running as root and we need to be the system user to set

        // the property. http://b/11463182

        //萬一runtime切換成上次啟動,例如上次runtime因為OTA被删除了,我們需要設定一個系統屬性以便于同步

        //我們不能在一個回退到的runtime中初始化代碼,因為它已經作為root運作了

        SystemProperties.set("persist.sys.dalvik.vm.lib.2", VMRuntime.getRuntime().vmLibrary());

        // Enable the sampling profiler.

        if (SamplingProfilerIntegration.isEnabled()) {

            SamplingProfilerIntegration.start();

            mProfilerSnapshotTimer = new Timer();

            mProfilerSnapshotTimer.schedule(new TimerTask() {

                @Override

                public void run() {

                    SamplingProfilerIntegration.writeSnapshot("system_server", null);

                }

            }, SNAPSHOT_INTERVAL, SNAPSHOT_INTERVAL);

        }

        // Mmmmmm... more memory!

        VMRuntime.getRuntime().clearGrowthLimit();

        // The system server has to run all of the time, so it needs to be

        // as efficient as possible with its memory usage.

        //系統system server必須一直運作,是以它需要盡可能的高效使用記憶體

        VMRuntime.getRuntime().setTargetHeapUtilization(0.8f);

        // Some devices rely on runtime fingerprint generation, so make sure

        // we've defined it before booting further.

        //一些裝置依賴runtime指紋生成,是以我們應該確定在啟動之前就定義了它

        Build.ensureFingerprintProperty();

        // Within the system server, it is an error to access Environment paths without

        // explicitly specifying a user.

        //在system server中,隐式确定的使用者通路環境路徑是錯誤的

        Environment.setUserRequired(true);

        // Ensure binder calls into the system always run at foreground priority.

        //確定binder與system通信時總是以前台優先級運作

        BinderInternal.disableBackgroundScheduling(true);

        // Prepare the main looper thread (this thread).

        android.os.Process.setThreadPriority(

                android.os.Process.THREAD_PRIORITY_FOREGROUND);

        android.os.Process.setCanSelfBackground(false);

        Looper.prepareMainLooper();

        // Initialize native services.

        System.loadLibrary("android_servers");

        nativeInit();

        // Check whether we failed to shut down last time we tried.

        // This call may not return.

        performPendingShutdown();

        // Initialize the system context.

        //初始化了systemcontext,通過ActivityThr

ead建立

        createSystemContext();

        // Create the system service manager.

        mSystemServiceManager = new SystemServiceManager(mSystemContext);

//将mSystemServiceManager存儲到數組中,通過鍵值對指定mSystemServiceManager為SystemServiceManager

        LocalServices.addService(SystemServiceManager.class, mSystemServiceManager);

        // Start services.

        try {

            startBootstrapServices();

            startCoreServices();

            startOtherServices();

        } catch (Throwable ex) {

            Slog.e("System", "******************************************");

            Slog.e("System", "************ Failure starting system services", ex);

            throw ex;

        }

        // For debug builds, log event loop stalls to dropbox for analysis.

        if (StrictMode.conditionallyEnableDebugLogging()) {

            Slog.i(TAG, "Enabled StrictMode for system server main thread.");

        }

        // Loop forever.

        Looper.loop();

        throw new RuntimeException("Main thread loop unexpectedly exited");

    }

初始化各種服務調用的是nativeInit();方法涉及到native層的實作,我們隻需要知道它初始化了什麼服務就好

systemserver探究筆記

接下來,讓我們看看startBootstrapServices();startCoreServices();startOtherServices();這三個函數分别幹了什麼

startBootstrapServices();

    private void startBootstrapServices() {

        // Wait for installd to finish starting up so that it has a chance to

        // create critical directories such as /data/user with the appropriate

        // permissions.  We need this to complete before we initialize other services.

        Installer installer = mSystemServiceManager.startService(Installer.class);

        // Activity manager runs the show.

        mActivityManagerService = mSystemServiceManager.startService(

                ActivityManagerService.Lifecycle.class).getService();

        mActivityManagerService.setSystemServiceManager(mSystemServiceManager);

        mActivityManagerService.setInstaller(installer);

        // Power manager needs to be started early because other services need it.

        // Native daemons may be watching for it to be registered so it must be ready

        // to handle incoming binder calls immediately (including being able to verify

        // the permissions for those calls).

        mPowerManagerService = mSystemServiceManager.startService(PowerManagerService.class);

        // Now that the power manager has been started, let the activity manager

        // initialize power management features.

        mActivityManagerService.initPowerManagement();

        // Display manager is needed to provide display metrics before package manager

        // starts up.

        mDisplayManagerService = mSystemServiceManager.startService(DisplayManagerService.class);

        // We need the default display before we can initialize the package manager.

        mSystemServiceManager.startBootPhase(SystemService.PHASE_WAIT_FOR_DEFAULT_DISPLAY);

        // Only run "core" apps if we're encrypting the device.

        String cryptState = SystemProperties.get("vold.decrypt");

        if (ENCRYPTING_STATE.equals(cryptState)) {

            Slog.w(TAG, "Detected encryption in progress - only parsing core apps");

            mOnlyCore = true;

        } else if (ENCRYPTED_STATE.equals(cryptState)) {

            Slog.w(TAG, "Device encrypted - only parsing core apps");

            mOnlyCore = true;

        }

        // Start the package manager.

        Slog.i(TAG, "Package Manager");

        mPackageManagerService = PackageManagerService.main(mSystemContext, installer,

                mFactoryTestMode != FactoryTest.FACTORY_TEST_OFF, mOnlyCore);

        mFirstBoot = mPackageManagerService.isFirstBoot();

        mPackageManager = mSystemContext.getPackageManager();

        Slog.i(TAG, "User Service");

        ServiceManager.addService(Context.USER_SERVICE, UserManagerService.getInstance());

        // Initialize attribute cache used to cache resources from packages.

        AttributeCache.init(mSystemContext);

        // Set up the Application instance for the system process and get started.

        mActivityManagerService.setSystemProcess();

    }

代碼這麼多,我總結了一下

1.建立了AMS并啟動它,關于它的啟動采用了JAVA的反射機制。源碼如下

mActivityManagerService = mSystemServiceManager.startService(
                ActivityManagerService.Lifecycle.class).getService();
        mActivityManagerService.setSystemServiceManager(mSystemServiceManager);
        mActivityManagerService.setInstaller(installer);
           

startServer中通過反射機制拿到ActivityManagerService.Lifecycle的執行個體

public static final class Lifecycle extends SystemService {
        private final ActivityManagerService mService;

        public Lifecycle(Context context) {
            super(context);
            mService = new ActivityManagerService(context);
        }

        @Override
        public void onStart() {
            mService.start();
        }

        public ActivityManagerService getService() {
            return mService;
        }
    }
           

再通過getService拿到AMS,而構造AMS所傳入的context就是構造mSystemServiceManager所用的context

2.開啟其他服務,例如PMS,調用了PMS.main方法

3.為系統程序建立APP執行個體并啟動

startCoreServices();

這個沒什麼好說的,開啟一些必要服務,燈光電池什麼的

    private void startCoreServices() {

        // Manages LEDs and display backlight.

        mSystemServiceManager.startService(LightsService.class);

        // Tracks the battery level.  Requires LightService.

        mSystemServiceManager.startService(BatteryService.class);

        // Tracks application usage stats.

        mSystemServiceManager.startService(UsageStatsService.class);

        mActivityManagerService.setUsageStatsManager(

                LocalServices.getService(UsageStatsManagerInternal.class));

        // Update after UsageStatsService is available, needed before performBootDexOpt.

        mPackageManagerService.getUsageStatsIfNoPackageUsageInfo();

        // Tracks whether the updatable WebView is in a ready state and watches for update installs.

        mSystemServiceManager.startService(WebViewUpdateService.class);

    }

startOtherServices();

    private void startOtherServices() {

        final Context context = mSystemContext;

        AccountManagerService accountManager = null;

        ContentService contentService = null;

        VibratorService vibrator = null;

        IAlarmManager alarm = null;

        MountService mountService = null;

        NetworkManagementService networkManagement = null;

        NetworkStatsService networkStats = null;

        NetworkPolicyManagerService networkPolicy = null;

        ConnectivityService connectivity = null;

        NetworkScoreService networkScore = null;

        NsdService serviceDiscovery= null;

        WindowManagerService wm = null;

        BluetoothManagerService bluetooth = null;

        UsbService usb = null;

        SerialService serial = null;

        NetworkTimeUpdateService networkTimeUpdater = null;

        CommonTimeManagementService commonTimeMgmtService = null;

        InputManagerService inputManager = null;

        TelephonyRegistry telephonyRegistry = null;

        ConsumerIrService consumerIr = null;

        AudioService audioService = null;

        MmsServiceBroker mmsService = null;

        boolean disableStorage = SystemProperties.getBoolean("config.disable_storage", false);

        boolean disableMedia = SystemProperties.getBoolean("config.disable_media", false);

        boolean disableBluetooth = SystemProperties.getBoolean("config.disable_bluetooth", false);

        boolean disableTelephony = SystemProperties.getBoolean("config.disable_telephony", false);

        boolean disableLocation = SystemProperties.getBoolean("config.disable_location", false);

        boolean disableSystemUI = SystemProperties.getBoolean("config.disable_systemui", false);

        boolean disableNonCoreServices = SystemProperties.getBoolean("config.disable_noncore", false);

        boolean disableNetwork = SystemProperties.getBoolean("config.disable_network", false);

        boolean disableNetworkTime = SystemProperties.getBoolean("config.disable_networktime", false);

        boolean isEmulator = SystemProperties.get("ro.kernel.qemu").equals("1");

        boolean digitalPenCapable =

            Resources.getSystem().getBoolean(com.android.internal.R.bool.config_digitalPenCapable);

        boolean disableAtlas = SystemProperties.getBoolean("config.disable_atlas", false);

        String[] externalServices = Resources.getSystem()

                .getStringArray(com.android.internal.R.array.config_externalCMServices);

        try {

            Slog.i(TAG, "Reading configuration...");

            SystemConfig.getInstance();

            Slog.i(TAG, "Scheduling Policy");

            ServiceManager.addService("scheduling_policy", new SchedulingPolicyService());

            mSystemServiceManager.startService(TelecomLoaderService.class);

            Slog.i(TAG, "Telephony Registry");

            telephonyRegistry = new TelephonyRegistry(context);

            ServiceManager.addService("telephony.registry", telephonyRegistry);

            Slog.i(TAG, "Entropy Mixer");

            ServiceManager.addService("entropy", new EntropyMixer(context));

            mContentResolver = context.getContentResolver();

            // The AccountManager must come before the ContentService

            try {

                // TODO: seems like this should be disable-able, but req'd by ContentService

                Slog.i(TAG, "Account Manager");

                accountManager = new AccountManagerService(context);

                ServiceManager.addService(Context.ACCOUNT_SERVICE, accountManager);

            } catch (Throwable e) {

                Slog.e(TAG, "Failure starting Account Manager", e);

            }

            Slog.i(TAG, "Content Manager");

            contentService = ContentService.main(context,

                    mFactoryTestMode == FactoryTest.FACTORY_TEST_LOW_LEVEL);

            Slog.i(TAG, "System Content Providers");

            mActivityManagerService.installSystemProviders();

            Slog.i(TAG, "Vibrator Service");

            vibrator = new VibratorService(context);

            ServiceManager.addService("vibrator", vibrator);

            Slog.i(TAG, "Consumer IR Service");

            consumerIr = new ConsumerIrService(context);

            ServiceManager.addService(Context.CONSUMER_IR_SERVICE, consumerIr);

            mAlarmManagerService = mSystemServiceManager.startService(AlarmManagerService.class);

            alarm = IAlarmManager.Stub.asInterface(

                    ServiceManager.getService(Context.ALARM_SERVICE));

            Slog.i(TAG, "Init Watchdog");

            final Watchdog watchdog = Watchdog.getInstance();

            watchdog.init(context, mActivityManagerService);

            Slog.i(TAG, "Input Manager");

            inputManager = new InputManagerService(context);

            Slog.i(TAG, "Window Manager");

            wm = WindowManagerService.main(context, inputManager,

                    mFactoryTestMode != FactoryTest.FACTORY_TEST_LOW_LEVEL,

                    true, mOnlyCore);

            ServiceManager.addService(Context.WINDOW_SERVICE, wm);

            ServiceManager.addService(Context.INPUT_SERVICE, inputManager);

            mActivityManagerService.setWindowManager(wm);

            inputManager.setWindowManagerCallbacks(wm.getInputMonitor());

            inputManager.start();

            // TODO: Use service dependencies instead.

            mDisplayManagerService.windowManagerAndInputReady();

            // Skip Bluetooth if we have an emulator kernel

            // TODO: Use a more reliable check to see if this product should

            // support Bluetooth - see bug 988521

            if (isEmulator) {

                Slog.i(TAG, "No Bluetooh Service (emulator)");

            } else if (mFactoryTestMode == FactoryTest.FACTORY_TEST_LOW_LEVEL) {

                Slog.i(TAG, "No Bluetooth Service (factory test)");

            } else if (!context.getPackageManager().hasSystemFeature

                       (PackageManager.FEATURE_BLUETOOTH)) {

                Slog.i(TAG, "No Bluetooth Service (Bluetooth Hardware Not Present)");

            } else if (disableBluetooth) {

                Slog.i(TAG, "Bluetooth Service disabled by config");

            } else {

                Slog.i(TAG, "Bluetooth Manager Service");

                bluetooth = new BluetoothManagerService(context);

                ServiceManager.addService(BluetoothAdapter.BLUETOOTH_MANAGER_SERVICE, bluetooth);

            }

        } catch (RuntimeException e) {

            Slog.e("System", "******************************************");

            Slog.e("System", "************ Failure starting core service", e);

        }

        StatusBarManagerService statusBar = null;

        INotificationManager notification = null;

        InputMethodManagerService imm = null;

        WallpaperManagerService wallpaper = null;

        LocationManagerService location = null;

        CountryDetectorService countryDetector = null;

        TextServicesManagerService tsms = null;

        LockSettingsService lockSettings = null;

        AssetAtlasService atlas = null;

        MediaRouterService mediaRouter = null;

        EdgeGestureService edgeGestureService = null;

        GestureService gestureService = null;

        ThemeService themeService = null;

        KillSwitchService killSwitchService = null;

        // Bring up services needed for UI.

        if (mFactoryTestMode != FactoryTest.FACTORY_TEST_LOW_LEVEL) {

            //if (!disableNonCoreServices) { // TODO: View depends on these; mock them?

            if (true) {

                try {

                    Slog.i(TAG, "Input Method Service");

                    imm = new InputMethodManagerService(context, wm);

                    ServiceManager.addService(Context.INPUT_METHOD_SERVICE, imm);

                } catch (Throwable e) {

                    reportWtf("starting Input Manager Service", e);

                }

                try {

                    Slog.i(TAG, "Accessibility Manager");

                    ServiceManager.addService(Context.ACCESSIBILITY_SERVICE,

                            new AccessibilityManagerService(context));

                } catch (Throwable e) {

                    reportWtf("starting Accessibility Manager", e);

                }

            }

        }

        try {

            wm.displayReady();

        } catch (Throwable e) {

            reportWtf("making display ready", e);

        }

        if (mFactoryTestMode != FactoryTest.FACTORY_TEST_LOW_LEVEL) {

            if (!disableStorage &&

                !"0".equals(SystemProperties.get("system_init.startmountservice"))) {

                try {

                    Slog.i(TAG, "Mount Service");

                    mountService = new MountService(context);

                    ServiceManager.addService("mount", mountService);

                } catch (Throwable e) {

                    reportWtf("starting Mount Service", e);

                }

            }

        }

        try {

            mPackageManagerService.performBootDexOpt();

        } catch (Throwable e) {

            reportWtf("performing boot dexopt", e);

        }

        try {

            ActivityManagerNative.getDefault().showBootMessage(

                    context.getResources().getText(

                            com.android.internal.R.string.android_upgrading_starting_apps),

                    false);

        } catch (RemoteException e) {

        }

        if (mFactoryTestMode != FactoryTest.FACTORY_TEST_LOW_LEVEL) {

            if (!disableNonCoreServices) {

                try {

                    Slog.i(TAG,  "LockSettingsService");

                    lockSettings = new LockSettingsService(context);

                    ServiceManager.addService("lock_settings", lockSettings);

                } catch (Throwable e) {

                    reportWtf("starting LockSettingsService service", e);

                }

                if (!SystemProperties.get(PERSISTENT_DATA_BLOCK_PROP).equals("")) {

                    mSystemServiceManager.startService(PersistentDataBlockService.class);

                }

                // Always start the Device Policy Manager, so that the API is compatible with

                // API8.

                mSystemServiceManager.startService(DevicePolicyManagerService.Lifecycle.class);

            }

            if (!disableSystemUI) {

                try {

                    Slog.i(TAG, "Status Bar");

                    statusBar = new StatusBarManagerService(context, wm);

                    ServiceManager.addService(Context.STATUS_BAR_SERVICE, statusBar);

                } catch (Throwable e) {

                    reportWtf("starting StatusBarManagerService", e);

                }

            }

            if (!disableNonCoreServices) {

                try {

                    Slog.i(TAG, "Clipboard Service");

                    ServiceManager.addService(Context.CLIPBOARD_SERVICE,

                            new ClipboardService(context));

                } catch (Throwable e) {

                    reportWtf("starting Clipboard Service", e);

                }

            }

            if (!disableNonCoreServices &&

                    mPackageManager.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH)) {

                try {

                    Slog.i(TAG, "TorchService");

                    ServiceManager.addService(Context.TORCH_SERVICE, new TorchService(context));

                } catch (Throwable e) {

                    reportWtf("starting Torch Service", e);

                }

            }

            if (!disableNetwork) {

                try {

                    Slog.i(TAG, "NetworkManagement Service");

                    networkManagement = NetworkManagementService.create(context);

                    ServiceManager.addService(Context.NETWORKMANAGEMENT_SERVICE, networkManagement);

                } catch (Throwable e) {

                    reportWtf("starting NetworkManagement Service", e);

                }

            }

            if (!disableNonCoreServices) {

                try {

                    Slog.i(TAG, "Text Service Manager Service");

                    tsms = new TextServicesManagerService(context);

                    ServiceManager.addService(Context.TEXT_SERVICES_MANAGER_SERVICE, tsms);

                } catch (Throwable e) {

                    reportWtf("starting Text Service Manager Service", e);

                }

            }

            if (!disableNetwork) {

                try {

                    Slog.i(TAG, "Network Score Service");

                    networkScore = new NetworkScoreService(context);

                    ServiceManager.addService(Context.NETWORK_SCORE_SERVICE, networkScore);

                } catch (Throwable e) {

                    reportWtf("starting Network Score Service", e);

                }

                try {

                    Slog.i(TAG, "NetworkStats Service");

                    networkStats = new NetworkStatsService(context, networkManagement, alarm);

                    ServiceManager.addService(Context.NETWORK_STATS_SERVICE, networkStats);

                } catch (Throwable e) {

                    reportWtf("starting NetworkStats Service", e);

                }

                try {

                    Slog.i(TAG, "NetworkPolicy Service");

                    networkPolicy = new NetworkPolicyManagerService(

                            context, mActivityManagerService,

                            (IPowerManager)ServiceManager.getService(Context.POWER_SERVICE),

                            networkStats, networkManagement);

                    ServiceManager.addService(Context.NETWORK_POLICY_SERVICE, networkPolicy);

                } catch (Throwable e) {

                    reportWtf("starting NetworkPolicy Service", e);

                }

                mSystemServiceManager.startService(WIFI_P2P_SERVICE_CLASS);

                mSystemServiceManager.startService(WIFI_SERVICE_CLASS);

                mSystemServiceManager.startService(

                            "com.android.server.wifi.WifiScanningService");

                mSystemServiceManager.startService("com.android.server.wifi.RttService");

                if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_ETHERNET)) {

                    mSystemServiceManager.startService(ETHERNET_SERVICE_CLASS);

                }

                try {

                    Slog.i(TAG, "Connectivity Service");

                    connectivity = new ConnectivityService(

                            context, networkManagement, networkStats, networkPolicy);

                    ServiceManager.addService(Context.CONNECTIVITY_SERVICE, connectivity);

                    networkStats.bindConnectivityManager(connectivity);

                    networkPolicy.bindConnectivityManager(connectivity);

                } catch (Throwable e) {

                    reportWtf("starting Connectivity Service", e);

                }

                try {

                    Slog.i(TAG, "Network Service Discovery Service");

                    serviceDiscovery = NsdService.create(context);

                    ServiceManager.addService(

                            Context.NSD_SERVICE, serviceDiscovery);

                } catch (Throwable e) {

                    reportWtf("starting Service Discovery Service", e);

                }

                try {

                    Slog.i(TAG, "DPM Service");

                    startDpmService(context);

                } catch (Throwable e) {

                    reportWtf("starting DpmService", e);

                }

            }

            if (!disableNonCoreServices) {

                try {

                    Slog.i(TAG, "UpdateLock Service");

                    ServiceManager.addService(Context.UPDATE_LOCK_SERVICE,

                            new UpdateLockService(context));

                } catch (Throwable e) {

                    reportWtf("starting UpdateLockService", e);

                }

            }

            if (mountService != null && !mOnlyCore) {

                mountService.waitForAsecScan();

            }

            try {

                if (accountManager != null)

                    accountManager.systemReady();

            } catch (Throwable e) {

                reportWtf("making Account Manager Service ready", e);

            }

            try {

                if (contentService != null)

                    contentService.systemReady();

            } catch (Throwable e) {

                reportWtf("making Content Service ready", e);

            }

            mSystemServiceManager.startService(NotificationManagerService.class);

            notification = INotificationManager.Stub.asInterface(

                    ServiceManager.getService(Context.NOTIFICATION_SERVICE));

            networkPolicy.bindNotificationManager(notification);

            mSystemServiceManager.startService(DeviceStorageMonitorService.class);

            if (!disableLocation) {

                try {

                    Slog.i(TAG, "Location Manager");

                    location = new LocationManagerService(context);

                    ServiceManager.addService(Context.LOCATION_SERVICE, location);

                } catch (Throwable e) {

                    reportWtf("starting Location Manager", e);

                }

                try {

                    Slog.i(TAG, "Country Detector");

                    countryDetector = new CountryDetectorService(context);

                    ServiceManager.addService(Context.COUNTRY_DETECTOR, countryDetector);

                } catch (Throwable e) {

                    reportWtf("starting Country Detector", e);

                }

            }

            if (!disableNonCoreServices) {

                try {

                    Slog.i(TAG, "Search Service");

                    ServiceManager.addService(Context.SEARCH_SERVICE,

                            new SearchManagerService(context));

                } catch (Throwable e) {

                    reportWtf("starting Search Service", e);

                }

            }

            try {

                Slog.i(TAG, "DropBox Service");

                ServiceManager.addService(Context.DROPBOX_SERVICE,

                        new DropBoxManagerService(context, new File("/data/system/dropbox")));

            } catch (Throwable e) {

                reportWtf("starting DropBoxManagerService", e);

            }

            if (!disableNonCoreServices && context.getResources().getBoolean(

                        R.bool.config_enableWallpaperService)) {

                try {

                    Slog.i(TAG, "Wallpaper Service");

                    wallpaper = new WallpaperManagerService(context);

                    ServiceManager.addService(Context.WALLPAPER_SERVICE, wallpaper);

                } catch (Throwable e) {

                    reportWtf("starting Wallpaper Service", e);

                }

            }

            if (!disableMedia && !"0".equals(SystemProperties.get("system_init.startaudioservice"))) {

                try {

                    Slog.i(TAG, "Audio Service");

                    audioService = new AudioService(context);

                    ServiceManager.addService(Context.AUDIO_SERVICE, audioService);

                } catch (Throwable e) {

                    reportWtf("starting Audio Service", e);

                }

            }

            if (!disableNonCoreServices) {

                mSystemServiceManager.startService(DockObserver.class);

            }

            if (!disableMedia) {

                try {

                    Slog.i(TAG, "Wired Accessory Manager");

                    // Listen for wired headset changes

                    inputManager.setWiredAccessoryCallbacks(

                            new WiredAccessoryManager(context, inputManager));

                } catch (Throwable e) {

                    reportWtf("starting WiredAccessoryManager", e);

                }

            }

            if (!disableNonCoreServices) {

                if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_USB_HOST)

                        || mPackageManager.hasSystemFeature(

                                PackageManager.FEATURE_USB_ACCESSORY)) {

                    // Manage USB host and device support

                    mSystemServiceManager.startService(USB_SERVICE_CLASS);

                }

                try {

                    Slog.i(TAG, "Serial Service");

                    // Serial port support

                    serial = new SerialService(context);

                    ServiceManager.addService(Context.SERIAL_SERVICE, serial);

                } catch (Throwable e) {

                    Slog.e(TAG, "Failure starting SerialService", e);

                }

            }

            mSystemServiceManager.startService(TwilightService.class);

            mSystemServiceManager.startService(UiModeManagerService.class);

            mSystemServiceManager.startService(JobSchedulerService.class);

            if (!disableNonCoreServices) {

                if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_BACKUP)) {

                    mSystemServiceManager.startService(BACKUP_MANAGER_SERVICE_CLASS);

                }

                if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_APP_WIDGETS)) {

                    mSystemServiceManager.startService(APPWIDGET_SERVICE_CLASS);

                }

                if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_VOICE_RECOGNIZERS)) {

                    mSystemServiceManager.startService(VOICE_RECOGNITION_MANAGER_SERVICE_CLASS);

                }

            }

            try {

                Slog.i(TAG, "DiskStats Service");

                ServiceManager.addService("diskstats", new DiskStatsService(context));

            } catch (Throwable e) {

                reportWtf("starting DiskStats Service", e);

            }

            try {

                // need to add this service even if SamplingProfilerIntegration.isEnabled()

                // is false, because it is this service that detects system property change and

                // turns on SamplingProfilerIntegration. Plus, when sampling profiler doesn't work,

                // there is little overhead for running this service.

                Slog.i(TAG, "SamplingProfiler Service");

                ServiceManager.addService("samplingprofiler",

                            new SamplingProfilerService(context));

            } catch (Throwable e) {

                reportWtf("starting SamplingProfiler Service", e);

            }

            if (!disableNetwork && !disableNetworkTime) {

                try {

                    Slog.i(TAG, "NetworkTimeUpdateService");

                    networkTimeUpdater = new NetworkTimeUpdateService(context);

                } catch (Throwable e) {

                    reportWtf("starting NetworkTimeUpdate service", e);

                }

            }

            if (!disableMedia) {

                try {

                    Slog.i(TAG, "CommonTimeManagementService");

                    commonTimeMgmtService = new CommonTimeManagementService(context);

                    ServiceManager.addService("commontime_management", commonTimeMgmtService);

                } catch (Throwable e) {

                    reportWtf("starting CommonTimeManagementService service", e);

                }

            }

            if (!disableNetwork) {

                try {

                    Slog.i(TAG, "CertBlacklister");

                    CertBlacklister blacklister = new CertBlacklister(context);

                } catch (Throwable e) {

                    reportWtf("starting CertBlacklister", e);

                }

            }

            if (!disableNonCoreServices) {

                // Dreams (interactive idle-time views, a/k/a screen savers, and doze mode)

                mSystemServiceManager.startService(DreamManagerService.class);

            }

            if (!disableNonCoreServices && !disableAtlas) {

                try {

                    Slog.i(TAG, "Assets Atlas Service");

                    atlas = new AssetAtlasService(context);

                    ServiceManager.addService(AssetAtlasService.ASSET_ATLAS_SERVICE, atlas);

                } catch (Throwable e) {

                    reportWtf("starting AssetAtlasService", e);

                }

            }

            if (context.getResources().getBoolean(

                    com.android.internal.R.bool.config_enableGestureService)) {

                try {

                    Slog.i(TAG, "Gesture Sensor Service");

                    gestureService = new GestureService(context, inputManager);

                    ServiceManager.addService("gesture", gestureService);

                } catch (Throwable e) {

                    Slog.e(TAG, "Failure starting Gesture Sensor Service", e);

                }

            }

            if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_PRINTING)) {

                mSystemServiceManager.startService(PRINT_MANAGER_SERVICE_CLASS);

            }

            mSystemServiceManager.startService(RestrictionsManagerService.class);

            mSystemServiceManager.startService(MediaSessionService.class);

            if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_HDMI_CEC)) {

                mSystemServiceManager.startService(HdmiControlService.class);

            }

            if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_LIVE_TV)) {

                mSystemServiceManager.startService(TvInputManagerService.class);

            }

            if (!disableNonCoreServices && !mOnlyCore) {

                try {

                    Slog.i(TAG, "Theme Service");

                    themeService = new ThemeService(context);

                    ServiceManager.addService(Context.THEME_SERVICE, themeService);

                } catch (Throwable e) {

                    reportWtf("starting Theme Service", e);

                }

            }

            try {

                Slog.i(TAG, "KillSwitch Service");

                killSwitchService = new KillSwitchService(context);

                ServiceManager.addService(Context.KILLSWITCH_SERVICE, killSwitchService);

            } catch (Throwable e) {

                reportWtf("starting KillSwitch Service", e);

            }

            if (!disableNonCoreServices) {

                try {

                    Slog.i(TAG, "Media Router Service");

                    mediaRouter = new MediaRouterService(context);

                    ServiceManager.addService(Context.MEDIA_ROUTER_SERVICE, mediaRouter);

                } catch (Throwable e) {

                    reportWtf("starting MediaRouterService", e);

                }

                mSystemServiceManager.startService(TrustManagerService.class);

                mSystemServiceManager.startService(FingerprintService.class);

                try {

                    Slog.i(TAG, "BackgroundDexOptService");

                    BackgroundDexOptService.schedule(context);

                } catch (Throwable e) {

                    reportWtf("starting BackgroundDexOptService", e);

                }

            }

            mSystemServiceManager.startService(LauncherAppsService.class);

            boolean isWipowerEnabled = SystemProperties.getBoolean("ro.bluetooth.wipower", false);

            if (isWipowerEnabled) {

                try {

                    final String WBC_SERVICE_NAME = "wbc_service";

                    Slog.i(TAG, "WipowerBatteryControl Service");

                    PathClassLoader wbcClassLoader =

                        new PathClassLoader("/system/framework/com.quicinc.wbc.jar:/system/framework/com.quicinc.wbcservice.jar",

                                            ClassLoader.getSystemClassLoader());

                    Class wbcClass = wbcClassLoader.loadClass("com.quicinc.wbcservice.WbcService");

                    Constructor<Class> ctor = wbcClass.getConstructor(Context.class);

                    Object wbcObject = ctor.newInstance(context);

                    Slog.d(TAG, "Successfully loaded WbcService class");

                    ServiceManager.addService(WBC_SERVICE_NAME, (IBinder) wbcObject);

                } catch (Throwable e) {

                    reportWtf("starting WipowerBatteryControl Service", e);

                }

            } else {

                Slog.d(TAG, "Wipower not supported");

            }

            if (digitalPenCapable) {

              try {

                  Slog.i(TAG, "Digital Pen Service");

                  PathClassLoader digitalPenClassLoader =

                    new PathClassLoader("/system/framework/DigitalPenService.jar",

                                        ClassLoader.getSystemClassLoader());

                  Class digitalPenClass = digitalPenClassLoader.loadClass

                    ("com.qti.snapdragon.digitalpen.DigitalPenService");

                  Constructor<Class> ctor = digitalPenClass.getConstructor(Context.class);

                  Object digitalPenRemoteObject = ctor.newInstance(context);

                  Slog.i(TAG, "Successfully loaded DigitalPenService class");

                  ServiceManager.addService("DigitalPen", (IBinder)digitalPenRemoteObject);

              } catch (Throwable e) {

                  reportWtf("starting DigitalPenService", e);

              }

            }

            try {

                Slog.i(TAG, "EdgeGesture service");

                edgeGestureService = new EdgeGestureService(context, inputManager);

                ServiceManager.addService("edgegestureservice", edgeGestureService);

            } catch (Throwable e) {

                Slog.e(TAG, "Failure starting EdgeGesture service", e);

            }

        }

        if (!disableNonCoreServices) {

            mSystemServiceManager.startService(MediaProjectionManagerService.class);

        }

        // make sure the ADB_ENABLED setting value matches the secure property value

        Settings.Secure.putInt(mContentResolver, Settings.Secure.ADB_PORT,

                Integer.parseInt(SystemProperties.get("service.adb.tcp.port", "-1")));

        // register observer to listen for settings changes

        mContentResolver.registerContentObserver(

            Settings.Secure.getUriFor(Settings.Secure.ADB_PORT),

            false, new AdbPortObserver());

        // Before things start rolling, be sure we have decided whether

        // we are in safe mode.

        final boolean safeMode = wm.detectSafeMode();

        if (safeMode) {

            mActivityManagerService.enterSafeMode();

            // Disable the JIT for the system_server process

            VMRuntime.getRuntime().disableJitCompilation();

        } else {

            // Enable the JIT for the system_server process

            VMRuntime.getRuntime().startJitCompilation();

        }

        // MMS service broker

        mmsService = mSystemServiceManager.startService(MmsServiceBroker.class);

        // Externally-defined services

        for (String service : externalServices) {

            try {

                Slog.i(TAG, service);

                mSystemServiceManager.startService(service);

            } catch (Throwable e) {

                reportWtf("starting " + service , e);

            }

        }

        // It is now time to start up the app processes...

        try {

            vibrator.systemReady();

        } catch (Throwable e) {

            reportWtf("making Vibrator Service ready", e);

        }

        if (lockSettings != null) {

            try {

                lockSettings.systemReady();

            } catch (Throwable e) {

                reportWtf("making Lock Settings Service ready", e);

            }

        }

        // Needed by DevicePolicyManager for initialization

        mSystemServiceManager.startBootPhase(SystemService.PHASE_LOCK_SETTINGS_READY);

        mSystemServiceManager.startBootPhase(SystemService.PHASE_SYSTEM_SERVICES_READY);

        try {

            wm.systemReady();

        } catch (Throwable e) {

            reportWtf("making Window Manager Service ready", e);

        }

        if (safeMode) {

            mActivityManagerService.showSafeModeOverlay();

        }

        // Update the configuration for this context by hand, because we're going

        // to start using it before the config change done in wm.systemReady() will

        // propagate to it.

        Configuration config = wm.computeNewConfiguration();

        DisplayMetrics metrics = new DisplayMetrics();

        WindowManager w = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);

        w.getDefaultDisplay().getMetrics(metrics);

        context.getResources().updateConfiguration(config, metrics);

        try {

            // TODO: use boot phase

            mPowerManagerService.systemReady(mActivityManagerService.getAppOpsService());

        } catch (Throwable e) {

            reportWtf("making Power Manager Service ready", e);

        }

        try {

            mPackageManagerService.systemReady();

        } catch (Throwable e) {

            reportWtf("making Package Manager Service ready", e);

        }

        try {

            // TODO: use boot phase and communicate these flags some other way

            mDisplayManagerService.systemReady(safeMode, mOnlyCore);

        } catch (Throwable e) {

            reportWtf("making Display Manager Service ready", e);

        }

        if (edgeGestureService != null) {

            try {

                edgeGestureService.systemReady();

            } catch (Throwable e) {

                reportWtf("making EdgeGesture service ready", e);

            }

        }

        if (gestureService != null) {

            try {

                gestureService.systemReady();

            } catch (Throwable e) {

                reportWtf("making Gesture Sensor Service ready", e);

            }

        }

        IntentFilter filter = new IntentFilter();

        filter.addAction(Intent.ACTION_APP_FAILURE);

        filter.addAction(Intent.ACTION_APP_FAILURE_RESET);

        filter.addAction(Intent.ACTION_PACKAGE_ADDED);

        filter.addAction(Intent.ACTION_PACKAGE_REMOVED);

        filter.addAction(ThemeUtils.ACTION_THEME_CHANGED);

        filter.addCategory(Intent.CATEGORY_THEME_PACKAGE_INSTALLED_STATE_CHANGE);

        filter.addDataScheme("package");

        context.registerReceiver(new AppsFailureReceiver(), filter);

        // These are needed to propagate to the runnable below.

        final MountService mountServiceF = mountService;

        final NetworkManagementService networkManagementF = networkManagement;

        final NetworkStatsService networkStatsF = networkStats;

        final NetworkPolicyManagerService networkPolicyF = networkPolicy;

        final ConnectivityService connectivityF = connectivity;

        final NetworkScoreService networkScoreF = networkScore;

        final WallpaperManagerService wallpaperF = wallpaper;

        final InputMethodManagerService immF = imm;

        final LocationManagerService locationF = location;

        final CountryDetectorService countryDetectorF = countryDetector;

        final NetworkTimeUpdateService networkTimeUpdaterF = networkTimeUpdater;

        final CommonTimeManagementService commonTimeMgmtServiceF = commonTimeMgmtService;

        final TextServicesManagerService textServiceManagerServiceF = tsms;

        final StatusBarManagerService statusBarF = statusBar;

        final AssetAtlasService atlasF = atlas;

        final InputManagerService inputManagerF = inputManager;

        final TelephonyRegistry telephonyRegistryF = telephonyRegistry;

        final MediaRouterService mediaRouterF = mediaRouter;

        final AudioService audioServiceF = audioService;

        final MmsServiceBroker mmsServiceF = mmsService;

        final ThemeService themeServiceF = themeService;

        // We now tell the activity manager it is okay to run third party

        // code.  It will call back into us once it has gotten to the state

        // where third party code can really run (but before it has actually

        // started launching the initial applications), for us to complete our

        // initialization.

        mActivityManagerService.systemReady(new Runnable() {

            @Override

            public void run() {

                Slog.i(TAG, "Making services ready");

                mSystemServiceManager.startBootPhase(

                        SystemService.PHASE_ACTIVITY_MANAGER_READY);

                try {

                    mActivityManagerService.startObservingNativeCrashes();

                } catch (Throwable e) {

                    reportWtf("observing native crashes", e);

                }

                Slog.i(TAG, "WebViewFactory preparation");

                WebViewFactory.prepareWebViewInSystemServer();

                // Start Nfc before SystemUi to ensure NfcTile and other apps gets a

                // valid NfcAdapter from NfcManager

                try {

                    startNfcService(context);

                } catch (Throwable e) {

                    // Don't crash. Nfc is an optional service. Just annotate that isn't ready

                    Slog.e(TAG, "Nfc service didn't start. Nfc will not be available.", e);

                }

                try {

                    startSystemUi(context);

                } catch (Throwable e) {

                    reportWtf("starting System UI", e);

                }

                try {

                    if (mountServiceF != null) mountServiceF.systemReady();

                } catch (Throwable e) {

                    reportWtf("making Mount Service ready", e);

                }

                try {

                    if (networkScoreF != null) networkScoreF.systemReady();

                } catch (Throwable e) {

                    reportWtf("making Network Score Service ready", e);

                }

                try {

                    if (networkManagementF != null) networkManagementF.systemReady();

                } catch (Throwable e) {

                    reportWtf("making Network Managment Service ready", e);

                }

                try {

                    if (networkStatsF != null) networkStatsF.systemReady();

                } catch (Throwable e) {

                    reportWtf("making Network Stats Service ready", e);

                }

                try {

                    if (networkPolicyF != null) networkPolicyF.systemReady();

                } catch (Throwable e) {

                    reportWtf("making Network Policy Service ready", e);

                }

                try {

                    if (connectivityF != null) connectivityF.systemReady();

                } catch (Throwable e) {

                    reportWtf("making Connectivity Service ready", e);

                }

                try {

                    if (audioServiceF != null) audioServiceF.systemReady();

                } catch (Throwable e) {

                    reportWtf("Notifying AudioService running", e);

                }

                Watchdog.getInstance().start();

                // It is now okay to let the various system services start their

                // third party code...

                mSystemServiceManager.startBootPhase(

                        SystemService.PHASE_THIRD_PARTY_APPS_CAN_START);

                try {

                    if (wallpaperF != null) wallpaperF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying WallpaperService running", e);

                }

                try {

                    if (immF != null) immF.systemRunning(statusBarF);

                } catch (Throwable e) {

                    reportWtf("Notifying InputMethodService running", e);

                }

                try {

                    if (locationF != null) locationF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying Location Service running", e);

                }

                try {

                    if (countryDetectorF != null) countryDetectorF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying CountryDetectorService running", e);

                }

                try {

                    if (networkTimeUpdaterF != null) networkTimeUpdaterF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying NetworkTimeService running", e);

                }

                try {

                    if (commonTimeMgmtServiceF != null) {

                        commonTimeMgmtServiceF.systemRunning();

                    }

                } catch (Throwable e) {

                    reportWtf("Notifying CommonTimeManagementService running", e);

                }

                try {

                    if (textServiceManagerServiceF != null)

                        textServiceManagerServiceF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying TextServicesManagerService running", e);

                }

                try {

                    if (atlasF != null) atlasF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying AssetAtlasService running", e);

                }

                try {

                    // TODO(BT) Pass parameter to input manager

                    if (inputManagerF != null) inputManagerF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying InputManagerService running", e);

                }

                try {

                    if (telephonyRegistryF != null) telephonyRegistryF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying TelephonyRegistry running", e);

                }

                try {

                    if (mediaRouterF != null) mediaRouterF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying MediaRouterService running", e);

                }

                try {

                    if (mmsServiceF != null) mmsServiceF.systemRunning();

                } catch (Throwable e) {

                    reportWtf("Notifying MmsService running", e);

                }

                try {

                    // now that the system is up, apply default theme if applicable

                    if (themeServiceF != null) themeServiceF.systemRunning();

                    ThemeConfig themeConfig =

                            ThemeConfig.getBootTheme(context.getContentResolver());

                    String iconPkg = themeConfig.getIconPackPkgName();

                    mPackageManagerService.updateIconMapping(iconPkg);

                } catch (Throwable e) {

                    reportWtf("Icon Mapping failed", e);

                }

            }

        });

    }

代碼有點長,不過都大同小異,都是啟動一些我們平時常見的服務,ContentService,AlarmManagerService等等

當然最重要的還是WindowManagerService.main,還有mActivityManagerService.setWindowManager

還有wifi和網絡服務等等都是在這個方法裡開啟

啟動到這裡,systemserver可以算啟動完成了,寫得比較亂,不過感覺大緻功能還是弄清楚了

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