AMS的启动 （Android 10）

 
    /**
     * The main entry point from zygote.
     */
    public static void main(String[] args) {
        new SystemServer().run();// 调用run方法
    }

startBootstrapServices(t);

Installer installer = mSystemServiceManager.startService(Installer.class);
 
// Activity manager runs the show.
        t.traceBegin("StartActivityManager");
        // TODO: Might need to move after migration to WM.
        ActivityTaskManagerService atm = mSystemServiceManager.startService(
                ActivityTaskManagerService.Lifecycle.class).getService();
        mActivityManagerService = ActivityManagerService.Lifecycle.startService(
                mSystemServiceManager, atm);
        mActivityManagerService.setSystemServiceManager(mSystemServiceManager);
        mActivityManagerService.setInstaller(installer);
        mWindowManagerGlobalLock = atm.getGlobalLock();
        t.traceEnd();

public static final class Lifecycle extends SystemService {
        private final ActivityManagerService mService;
        private static ActivityTaskManagerService sAtm;
 
        public Lifecycle(Context context) {
            super(context);
            mService = new ActivityManagerService(context, sAtm);
        }
 
        public static ActivityManagerService startService(
                SystemServiceManager ssm, ActivityTaskManagerService atm) {
            sAtm = atm;
            return ssm.startService(ActivityManagerService.Lifecycle.class).getService();
        }
 
        @Override
        public void onStart() {
            mService.start();
        }
 
        @Override
        public void onBootPhase(int phase) {
            mService.mBootPhase = phase;
            if (phase == PHASE_SYSTEM_SERVICES_READY) {
                mService.mBatteryStatsService.systemServicesReady();
                mService.mServices.systemServicesReady();
            } else if (phase == PHASE_ACTIVITY_MANAGER_READY) {
                mService.startBroadcastObservers();
            } else if (phase == PHASE_THIRD_PARTY_APPS_CAN_START) {
                mService.mPackageWatchdog.onPackagesReady();
            }
        }
 
        @Override
        public void onCleanupUser(int userId) {
            mService.mBatteryStatsService.onCleanupUser(userId);
        }
 
        public ActivityManagerService getService() {
            return mService;
        }
    }

public void startService(@NonNull final SystemService service) {
        // Register it.
        mServices.add(service);
        // Start it.
        long time = SystemClock.elapsedRealtime();
        try {
            service.onStart();
        } catch (RuntimeException ex) {
            throw new RuntimeException("Failed to start service " + service.getClass().getName()
                    + ": onStart threw an exception", ex);
        }
        warnIfTooLong(SystemClock.elapsedRealtime() - time, service, "onStart");
    }

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

private void start() {
        removeAllProcessGroups();
        mProcessCpuThread.start();
 
        mBatteryStatsService.publish();
        mAppOpsService.publish();
        Slog.d("AppOps", "AppOpsService published");
        LocalServices.addService(ActivityManagerInternal.class, mInternal);
        mActivityTaskManager.onActivityManagerInternalAdded();
        mPendingIntentController.onActivityManagerInternalAdded();
        // Wait for the synchronized block started in mProcessCpuThread,
        // so that any other access to mProcessCpuTracker from main thread
        // will be blocked during mProcessCpuTracker initialization.
        try {
            mProcessCpuInitLatch.await();
        } catch (InterruptedException e) {
            Slog.wtf(TAG, "Interrupted wait during start", e);
            Thread.currentThread().interrupt();
            throw new IllegalStateException("Interrupted wait during start");
        }
    }