System Server是Android系统的核心，他在Dalvik虚拟机启动后立即开始初始化和运行。其它的系统服务在System Server进程的环境中运行。/base/services/java/com/android/server/SystemServer.java

Java代码
 

1. /**  
2.  * This method is called from Zygote to initialize the system. This will cause the native  
3.  * services (SurfaceFlinger, AudioFlinger, etc..) to be started. After that it will call back  
4.  * up into init2() to start the Android services.  
5.  */  
6. native public static void init1(String[] args);   
7.   
8. public static void main(String[] args) {   
9.     if (System.currentTimeMillis() < EARLIEST_SUPPORTED_TIME) {   
10.         // If a device’s clock is before 1970 (before 0), a lot of   
11.         // APIs crash dealing with negative numbers, notably   
12.         // java.io.File#setLastModified, so instead we fake it and   
13.         // hope that time from cell towers or NTP fixes it   
14.         // shortly.   
15.         Slog.w(TAG, “System clock is before 1970; setting to 1970.”);   
16.         SystemClock.setCurrentTimeMillis(EARLIEST_SUPPORTED_TIME);   
17.     }   
18.   
19.     if (SamplingProfilerIntegration.isEnabled()) {   
20.         SamplingProfilerIntegration.start();   
21.         timer = new Timer();   
22.         timer.schedule(new TimerTask() {   
23.             @Override  
24.             public void run() {   
25.                 SamplingProfilerIntegration.writeSnapshot(“system_server”);   
26.             }   
27.         }, SNAPSHOT_INTERVAL, SNAPSHOT_INTERVAL);   
28.     }   
29.   
30.     // The system server has to run all of the time, so it needs to be   
31.     // as efficient as possible with its memory usage.   
32.     VMRuntime.getRuntime().setTargetHeapUtilization(0.8f);   
33.        
34.     System.loadLibrary(“android_servers”);   
35.     init1(args);   
36. }   
37.   
38. public static final void init2() {   
39.     Slog.i(TAG, “Entered the Android system server!”);   
40.     Thread thr = new ServerThread();   
41.     thr.setName(“android.server.ServerThread”);   
42.     thr.start();   
43. }  

/** * This method is called from Zygote to initialize the system. This will cause the native * services (SurfaceFlinger, AudioFlinger, etc..) to be started. After that it will call back * up into init2() to start the Android services. */ native public static void init1(String[] args); public static void main(String[] args) { if (System.currentTimeMillis() < EARLIEST_SUPPORTED_TIME) { // 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. Slog.w(TAG, “System clock is before 1970; setting to 1970.”); SystemClock.setCurrentTimeMillis(EARLIEST_SUPPORTED_TIME); } if (SamplingProfilerIntegration.isEnabled()) { SamplingProfilerIntegration.start(); timer = new Timer(); timer.schedule(new TimerTask() { @Override public void run() { SamplingProfilerIntegration.writeSnapshot(“system_server”); } }, SNAPSHOT_INTERVAL, SNAPSHOT_INTERVAL); } // The system server has to run all of the time, so it needs to be // as efficient as possible with its memory usage. VMRuntime.getRuntime().setTargetHeapUtilization(0.8f); System.loadLibrary(“android_servers”); init1(args); } public static final void init2() { Slog.i(TAG, “Entered the Android system server!”); Thread thr = new ServerThread(); thr.setName(“android.server.ServerThread”); thr.start(); }

 在main函数中，首先检查系统时间设置和SamplingProfiler。然后加载一个叫android_servers的本地库，他提供本地方法的接口（源程序在framework/base/services/jni/目录中）。然后调用本地方法设置服务。具体执行设置的代码在frameworks/base/cmds/system_server/library/system_init.cpp中。

C代码
 

1. extern “C” status_t system_init()   
2. {   
3.     LOGI(“Entered system_init()”);   
4.        
5.     sp<ProcessState> proc(ProcessState::self());   
6.        
7.     sp<IServiceManager> sm = defaultServiceManager();   
8.     LOGI(“ServiceManager: %p\n”, sm.get());   
9.        
10.     sp<GrimReaper> grim = new GrimReaper();   
11.     sm->asBinder()->linkToDeath(grim, grim.get(), 0);   
12.        
13.     char propBuf[PROPERTY_VALUE_MAX];   
14.     property_get(“system_init.startsurfaceflinger”, propBuf, “1”);   
15.     if (strcmp(propBuf, “1”) == 0) {   
16.         // Start the SurfaceFlinger   
17.         SurfaceFlinger::instantiate();   
18.     }   
19.   
20.     // Start the sensor service   
21.     SensorService::instantiate();   
22.   
23.     // On the simulator, audioflinger et al don’t get started the   
24.     // same way as on the device, and we need to start them here   
25.     if (!proc->supportsProcesses()) {   
26.   
27.         // Start the AudioFlinger   
28.         AudioFlinger::instantiate();   
29.   
30.         // Start the media playback service   
31.         MediaPlayerService::instantiate();   
32.   
33.         // Start the camera service   
34.         CameraService::instantiate();   
35.   
36.         // Start the audio policy service   
37.         AudioPolicyService::instantiate();   
38.     }   
39.   
40.     // And now start the Android runtime.  We have to do this bit   
41.     // of nastiness because the Android runtime initialization requires   
42.     // some of the core system services to already be started.   
43.     // All other servers should just start the Android runtime at   
44.     // the beginning of their processes’s main(), before calling   
45.     // the init function.   
46.     LOGI(“System server: starting Android runtime.\n”);   
47.        
48.     AndroidRuntime* runtime = AndroidRuntime::getRuntime();   
49.   
50.     LOGI(“System server: starting Android services.\n”);   
51.     runtime->callStatic(“com/android/server/SystemServer”, “init2”);   
52.            
53.     // If running in our own process, just go into the thread   
54.     // pool.  Otherwise, call the initialization finished   
55.     // func to let this process continue its initilization.   
56.     if (proc->supportsProcesses()) {   
57.         LOGI(“System server: entering thread pool.\n”);   
58.         ProcessState::self()->startThreadPool();   
59.         IPCThreadState::self()->joinThreadPool();   
60.         LOGI(“System server: exiting thread pool.\n”);   
61.     }   
62.     return NO_ERROR;   
63. }  

extern “C” status_t system_init() { LOGI(“Entered system_init()”); sp<ProcessState> proc(ProcessState::self()); sp<IServiceManager> sm = defaultServiceManager(); LOGI(“ServiceManager: %p\n”, sm.get()); sp<GrimReaper> grim = new GrimReaper(); sm->asBinder()->linkToDeath(grim, grim.get(), 0); char propBuf[PROPERTY_VALUE_MAX]; property_get(“system_init.startsurfaceflinger”, propBuf, “1”); if (strcmp(propBuf, “1”) == 0) { // Start the SurfaceFlinger SurfaceFlinger::instantiate(); } // Start the sensor service SensorService::instantiate(); // On the simulator, audioflinger et al don’t get started the // same way as on the device, and we need to start them here if (!proc->supportsProcesses()) { // Start the AudioFlinger AudioFlinger::instantiate(); // Start the media playback service MediaPlayerService::instantiate(); // Start the camera service CameraService::instantiate(); // Start the audio policy service AudioPolicyService::instantiate(); } // And now start the Android runtime. We have to do this bit // of nastiness because the Android runtime initialization requires // some of the core system services to already be started. // All other servers should just start the Android runtime at // the beginning of their processes’s main(), before calling // the init function. LOGI(“System server: starting Android runtime.\n”); AndroidRuntime* runtime = AndroidRuntime::getRuntime(); LOGI(“System server: starting Android services.\n”); runtime->callStatic(“com/android/server/SystemServer”, “init2”); // If running in our own process, just go into the thread // pool. Otherwise, call the initialization finished // func to let this process continue its initilization. if (proc->supportsProcesses()) { LOGI(“System server: entering thread pool.\n”); ProcessState::self()->startThreadPool(); IPCThreadState::self()->joinThreadPool(); LOGI(“System server: exiting thread pool.\n”); } return NO_ERROR; }

 等初始化传感器，视频，音频等服务后，调用一个回调方法init2 (在SystemServer.java中)。在上面的代码可以看到，这个方法开启了ServerThread来初始化其它的服务。

Java代码
 

1. public void run() {   
2.      EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_SYSTEM_RUN,   
3.          SystemClock.uptimeMillis());   
4.   
5.      Looper.prepare();   
6.   
7.      android.os.Process.setThreadPriority(   
8.              android.os.Process.THREAD_PRIORITY_FOREGROUND);   
9.   
10.      BinderInternal.disableBackgroundScheduling(true);   
11.      android.os.Process.setCanSelfBackground(false);   
12.   
13.      // Check whether we failed to shut down last time we tried.   
14.      {   
15.          final String shutdownAction = SystemProperties.get(   
16.                  ShutdownThread.SHUTDOWN_ACTION_PROPERTY, “”);   
17.          if (shutdownAction != null && shutdownAction.length() > 0) {   
18.              boolean reboot = (shutdownAction.charAt(0) == ‘1’);   
19.   
20.              final String reason;   
21.              if (shutdownAction.length() > 1) {   
22.                  reason = shutdownAction.substring(1, shutdownAction.length());   
23.              } else {   
24.                  reason = null;   
25.              }   
26.   
27.              ShutdownThread.rebootOrShutdown(reboot, reason);   
28.          }   
29.      }   
30.   
31.      String factoryTestStr = SystemProperties.get(“ro.factorytest”);   
32.      int factoryTest = “”.equals(factoryTestStr) ? SystemServer.FACTORY_TEST_OFF   
33.              : Integer.parseInt(factoryTestStr);   
34.   
35.      LightsService lights = null;   
36.      PowerManagerService power = null;   
37.      BatteryService battery = null;   
38.      ConnectivityService connectivity = null;   
39.      IPackageManager pm = null;   
40.      Context context = null;   
41.      WindowManagerService wm = null;   
42.      BluetoothService bluetooth = null;   
43.      BluetoothA2dpService bluetoothA2dp = null;   
44.      HeadsetObserver headset = null;   
45.      DockObserver dock = null;   
46.      UsbService usb = null;   
47.      UiModeManagerService uiMode = null;   
48.      RecognitionManagerService recognition = null;   
49.      ThrottleService throttle = null;   
50.   
51.      // Critical services…   
52.      try {   
53.          Slog.i(TAG, “Entropy Service”);   
54.          ServiceManager.addService(“entropy”, new EntropyService());   
55.   
56.          Slog.i(TAG, “Power Manager”);   
57.          power = new PowerManagerService();   
58.          ServiceManager.addService(Context.POWER_SERVICE, power);   
59.   
60.          Slog.i(TAG, “Activity Manager”);   
61.          context = ActivityManagerService.main(factoryTest);   
62.   
63.          Slog.i(TAG, “Telephony Registry”);   
64.          ServiceManager.addService(“telephony.registry”, new TelephonyRegistry(context));   
65.   
66.          AttributeCache.init(context);   
67.   
68.          Slog.i(TAG, “Package Manager”);   
69.          pm = PackageManagerService.main(context,   
70.                  factoryTest != SystemServer.FACTORY_TEST_OFF);   
71.   
72.          ActivityManagerService.setSystemProcess();   
73.   
74.          mContentResolver = context.getContentResolver();   
75.   
76.          // The AccountManager must come before the ContentService   
77.          try {   
78.              Slog.i(TAG, “Account Manager”);   
79.              ServiceManager.addService(Context.ACCOUNT_SERVICE,   
80.                      new AccountManagerService(context));   
81.          } catch (Throwable e) {   
82.              Slog.e(TAG, “Failure starting Account Manager”, e);   
83.          }   
84.   
85.          Slog.i(TAG, “Content Manager”);   
86.          ContentService.main(context,   
87.                  factoryTest == SystemServer.FACTORY_TEST_LOW_LEVEL);   
88.   
89.          Slog.i(TAG, “System Content Providers”);   
90.          ActivityManagerService.installSystemProviders();   
91.   
92.          Slog.i(TAG, “Battery Service”);   
93.          battery = new BatteryService(context);   
94.          ServiceManager.addService(“battery”, battery);   
95.   
96.          Slog.i(TAG, “Lights Service”);   
97.          lights = new LightsService(context);   
98.   
99.          Slog.i(TAG, “Vibrator Service”);   
100.          ServiceManager.addService(“vibrator”, new VibratorService(context));   
101.   
102.          // only initialize the power service after we have started the   
103.          // lights service, content providers and the battery service.   
104.          power.init(context, lights, ActivityManagerService.getDefault(), battery);   
105.   
106.          Slog.i(TAG, “Alarm Manager”);   
107.          AlarmManagerService alarm = new AlarmManagerService(context);   
108.          ServiceManager.addService(Context.ALARM_SERVICE, alarm);   
109.   
110.          Slog.i(TAG, “Init Watchdog”);   
111.          Watchdog.getInstance().init(context, battery, power, alarm,   
112.                  ActivityManagerService.self());   
113.   
114.          Slog.i(TAG, “Window Manager”);   
115.          wm = WindowManagerService.main(context, power,   
116.                  factoryTest != SystemServer.FACTORY_TEST_LOW_LEVEL);   
117.          ServiceManager.addService(Context.WINDOW_SERVICE, wm);   
118.   
119.          ((ActivityManagerService)ServiceManager.getService(“activity”))   
120.                  .setWindowManager(wm);   
121.   
122.          // Skip Bluetooth if we have an emulator kernel   
123.          // TODO: Use a more reliable check to see if this product should   
124.          // support Bluetooth – see bug 988521   
125.          if (SystemProperties.get(“ro.kernel.qemu”).equals(“1”)) {   
126.              Slog.i(TAG, “Registering null Bluetooth Service (emulator)”);   
127.              ServiceManager.addService(BluetoothAdapter.BLUETOOTH_SERVICE, null);   
128.          } else if (factoryTest == SystemServer.FACTORY_TEST_LOW_LEVEL) {   
129.              Slog.i(TAG, “Registering null Bluetooth Service (factory test)”);   
130.              ServiceManager.addService(BluetoothAdapter.BLUETOOTH_SERVICE, null);   
131.          } else {   
132.              Slog.i(TAG, “Bluetooth Service”);   
133.              bluetooth = new BluetoothService(context);   
134.              ServiceManager.addService(BluetoothAdapter.BLUETOOTH_SERVICE, bluetooth);   
135.              bluetooth.initAfterRegistration();   
136.              bluetoothA2dp = new BluetoothA2dpService(context, bluetooth);   
137.              ServiceManager.addService(BluetoothA2dpService.BLUETOOTH_A2DP_SERVICE,   
138.                                        bluetoothA2dp);   
139.   
140.              int bluetoothOn = Settings.Secure.getInt(mContentResolver,   
141.                  Settings.Secure.BLUETOOTH_ON, 0);   
142.              if (bluetoothOn > 0) {   
143.                  bluetooth.enable();   
144.              }   
145.          }   
146.   
147.      } catch (RuntimeException e) {   
148.          Slog.e(“System”, “Failure starting core service”, e);   
149.      }   
150.   
151.      DevicePolicyManagerService devicePolicy = null;   
152.      StatusBarManagerService statusBar = null;   
153.      InputMethodManagerService imm = null;   
154.      AppWidgetService appWidget = null;   
155.      NotificationManagerService notification = null;   
156.      WallpaperManagerService wallpaper = null;   
157.      LocationManagerService location = null;   
158.   
159.      if (factoryTest != SystemServer.FACTORY_TEST_LOW_LEVEL) {   
160.          try {   
161.              Slog.i(TAG, “Device Policy”);   
162.              devicePolicy = new DevicePolicyManagerService(context);   
163.              ServiceManager.addService(Context.DEVICE_POLICY_SERVICE, devicePolicy);   
164.          } catch (Throwable e) {   
165.              Slog.e(TAG, “Failure starting DevicePolicyService”, e);   
166.          }   
167.   
168.          try {   
169.              Slog.i(TAG, “Status Bar”);   
170.              statusBar = new StatusBarManagerService(context);   
171.              ServiceManager.addService(Context.STATUS_BAR_SERVICE, statusBar);   
172.          } catch (Throwable e) {   
173.              Slog.e(TAG, “Failure starting StatusBarManagerService”, e);   
174.          }   
175.   
176.          try {   
177.              Slog.i(TAG, “Clipboard Service”);   
178.              ServiceManager.addService(Context.CLIPBOARD_SERVICE,   
179.                      new ClipboardService(context));   
180.          } catch (Throwable e) {   
181.              Slog.e(TAG, “Failure starting Clipboard Service”, e);   
182.          }   
183.   
184.          try {   
185.              Slog.i(TAG, “Input Method Service”);   
186.              imm = new InputMethodManagerService(context, statusBar);   
187.              ServiceManager.addService(Context.INPUT_METHOD_SERVICE, imm);   
188.          } catch (Throwable e) {   
189.              Slog.e(TAG, “Failure starting Input Manager Service”, e);   
190.          }   
191.   
192.          try {   
193.              Slog.i(TAG, “NetStat Service”);   
194.              ServiceManager.addService(“netstat”, new NetStatService(context));   
195.          } catch (Throwable e) {   
196.              Slog.e(TAG, “Failure starting NetStat Service”, e);   
197.          }   
198.   
199.          try {   
200.              Slog.i(TAG, “NetworkManagement Service”);   
201.              ServiceManager.addService(   
202.                      Context.NETWORKMANAGEMENT_SERVICE,   
203.                      NetworkManagementService.create(context));   
204.          } catch (Throwable e) {   
205.              Slog.e(TAG, “Failure starting NetworkManagement Service”, e);   
206.          }   
207.   
208.          try {   
209.              Slog.i(TAG, “Connectivity Service”);   
210.              connectivity = ConnectivityService.getInstance(context);   
211.              ServiceManager.addService(Context.CONNECTIVITY_SERVICE, connectivity);   
212.          } catch (Throwable e) {   
213.              Slog.e(TAG, “Failure starting Connectivity Service”, e);   
214.          }   
215.   
216.          try {   
217.              Slog.i(TAG, “Throttle Service”);   
218.              throttle = new ThrottleService(context);   
219.              ServiceManager.addService(   
220.                      Context.THROTTLE_SERVICE, throttle);   
221.          } catch (Throwable e) {   
222.              Slog.e(TAG, “Failure starting ThrottleService”, e);   
223.          }   
224.   
225.          try {   
226.            Slog.i(TAG, “Accessibility Manager”);   
227.            ServiceManager.addService(Context.ACCESSIBILITY_SERVICE,   
228.                    new AccessibilityManagerService(context));   
229.          } catch (Throwable e) {   
230.            Slog.e(TAG, “Failure starting Accessibility Manager”, e);   
231.          }   
232.   
233.          try {   
234.              /*  
235.               * NotificationManagerService is dependant on MountService,  
236.               * (for media / usb notifications) so we must start MountService first.  
237.               */  
238.              Slog.i(TAG, “Mount Service”);   
239.              ServiceManager.addService(“mount”, new MountService(context));   
240.          } catch (Throwable e) {   
241.              Slog.e(TAG, “Failure starting Mount Service”, e);   
242.          }   
243.   
244.          try {   
245.              Slog.i(TAG, “Notification Manager”);   
246.              notification = new NotificationManagerService(context, statusBar, lights);   
247.              ServiceManager.addService(Context.NOTIFICATION_SERVICE, notification);   
248.          } catch (Throwable e) {   
249.              Slog.e(TAG, “Failure starting Notification Manager”, e);   
250.          }   
251.   
252.          try {   
253.              Slog.i(TAG, “Device Storage Monitor”);   
254.              ServiceManager.addService(DeviceStorageMonitorService.SERVICE,   
255.                      new DeviceStorageMonitorService(context));   
256.          } catch (Throwable e) {   
257.              Slog.e(TAG, “Failure starting DeviceStorageMonitor service”, e);   
258.          }   
259.   
260.          try {   
261.              Slog.i(TAG, “Location Manager”);   
262.              location = new LocationManagerService(context);   
263.              ServiceManager.addService(Context.LOCATION_SERVICE, location);   
264.          } catch (Throwable e) {   
265.              Slog.e(TAG, “Failure starting Location Manager”, e);   
266.          }   
267.   
268.          try {   
269.              Slog.i(TAG, “Search Service”);   
270.              ServiceManager.addService(Context.SEARCH_SERVICE,   
271.                      new SearchManagerService(context));   
272.          } catch (Throwable e) {   
273.              Slog.e(TAG, “Failure starting Search Service”, e);   
274.          }   
275.   
276.          if (INCLUDE_DEMO) {   
277.              Slog.i(TAG, “Installing demo data…”);   
278.              (new DemoThread(context)).start();   
279.          }   
280.   
281.          try {   
282.              Slog.i(TAG, “DropBox Service”);   
283.              ServiceManager.addService(Context.DROPBOX_SERVICE,   
284.                      new DropBoxManagerService(context, new File(“/data/system/dropbox”)));   
285.          } catch (Throwable e) {   
286.              Slog.e(TAG, “Failure starting DropBoxManagerService”, e);   
287.          }   
288.   
289.          try {   
290.              Slog.i(TAG, “Wallpaper Service”);   
291.              wallpaper = new WallpaperManagerService(context);   
292.              ServiceManager.addService(Context.WALLPAPER_SERVICE, wallpaper);   
293.          } catch (Throwable e) {   
294.              Slog.e(TAG, “Failure starting Wallpaper Service”, e);   
295.          }   
296.   
297.          try {   
298.              Slog.i(TAG, “Audio Service”);   
299.              ServiceManager.addService(Context.AUDIO_SERVICE, new AudioService(context));   
300.          } catch (Throwable e) {   
301.              Slog.e(TAG, “Failure starting Audio Service”, e);   
302.          }   
303.   
304.          try {   
305.              Slog.i(TAG, “Headset Observer”);   
306.              // Listen for wired headset changes   
307.              headset = new HeadsetObserver(context);   
308.          } catch (Throwable e) {   
309.              Slog.e(TAG, “Failure starting HeadsetObserver”, e);   
310.          }   
311.   
312.          try {   
313.              Slog.i(TAG, “Dock Observer”);   
314.              // Listen for dock station changes   
315.              dock = new DockObserver(context, power);   
316.          } catch (Throwable e) {   
317.              Slog.e(TAG, “Failure starting DockObserver”, e);   
318.          }   
319.   
320.          try {   
321.              Slog.i(TAG, “USB Service”);   
322.              // Listen for USB changes   
323.              usb = new UsbService(context);   
324.              ServiceManager.addService(Context.USB_SERVICE, usb);   
325.          } catch (Throwable e) {   
326.              Slog.e(TAG, “Failure starting UsbService”, e);   
327.          }   
328.   
329.          try {   
330.              Slog.i(TAG, “UI Mode Manager Service”);   
331.              // Listen for UI mode changes   
332.              uiMode = new UiModeManagerService(context);   
333.          } catch (Throwable e) {   
334.              Slog.e(TAG, “Failure starting UiModeManagerService”, e);   
335.          }   
336.   
337.          try {   
338.              Slog.i(TAG, “Backup Service”);   
339.              ServiceManager.addService(Context.BACKUP_SERVICE,   
340.                      new BackupManagerService(context));   
341.          } catch (Throwable e) {   
342.              Slog.e(TAG, “Failure starting Backup Service”, e);   
343.          }   
344.   
345.          try {   
346.              Slog.i(TAG, “AppWidget Service”);   
347.              appWidget = new AppWidgetService(context);   
348.              ServiceManager.addService(Context.APPWIDGET_SERVICE, appWidget);   
349.          } catch (Throwable e) {   
350.              Slog.e(TAG, “Failure starting AppWidget Service”, e);   
351.          }   
352.   
353.          try {   
354.              Slog.i(TAG, “Recognition Service”);   
355.              recognition = new RecognitionManagerService(context);   
356.          } catch (Throwable e) {   
357.              Slog.e(TAG, “Failure starting Recognition Service”, e);   
358.          }   
359.             
360.          try {   
361.              Slog.i(TAG, “DiskStats Service”);   
362.              ServiceManager.addService(“diskstats”, new DiskStatsService(context));   
363.          } catch (Throwable e) {   
364.              Slog.e(TAG, “Failure starting DiskStats Service”, e);   
365.          }   
366.      }   
367.   
368.      // make sure the ADB_ENABLED setting value matches the secure property value   
369.      Settings.Secure.putInt(mContentResolver, Settings.Secure.ADB_ENABLED,   
370.              “1”.equals(SystemProperties.get(“persist.service.adb.enable”)) ? 1 : 0);   
371.   
372.      // register observer to listen for settings changes   
373.      mContentResolver.registerContentObserver(Settings.Secure.getUriFor(Settings.Secure.ADB_ENABLED),   
374.              false, new AdbSettingsObserver());   
375.   
376.      // Before things start rolling, be sure we have decided whether   
377.      // we are in safe mode.   
378.      final boolean safeMode = wm.detectSafeMode();   
379.      if (safeMode) {   
380.          try {   
381.              ActivityManagerNative.getDefault().enterSafeMode();   
382.              // Post the safe mode state in the Zygote class   
383.              Zygote.systemInSafeMode = true;   
384.              // Disable the JIT for the system_server process   
385.              VMRuntime.getRuntime().disableJitCompilation();   
386.          } catch (RemoteException e) {   
387.          }   
388.      } else {   
389.          // Enable the JIT for the system_server process   
390.          VMRuntime.getRuntime().startJitCompilation();   
391.      }   
392.   
393.      // It is now time to start up the app processes…   
394.   
395.      if (devicePolicy != null) {   
396.          devicePolicy.systemReady();   
397.      }   
398.   
399.      if (notification != null) {   
400.          notification.systemReady();   
401.      }   
402.   
403.      if (statusBar != null) {   
404.          statusBar.systemReady();   
405.      }   
406.      wm.systemReady();   
407.      power.systemReady();   
408.      try {   
409.          pm.systemReady();   
410.      } catch (RemoteException e) {   
411.      }   
412.   
413.      // These are needed to propagate to the runnable below.   
414.      final StatusBarManagerService statusBarF = statusBar;   
415.      final BatteryService batteryF = battery;   
416.      final ConnectivityService connectivityF = connectivity;   
417.      final DockObserver dockF = dock;   
418.      final UsbService usbF = usb;   
419.      final ThrottleService throttleF = throttle;   
420.      final UiModeManagerService uiModeF = uiMode;   
421.      final AppWidgetService appWidgetF = appWidget;   
422.      final WallpaperManagerService wallpaperF = wallpaper;   
423.      final InputMethodManagerService immF = imm;   
424.      final RecognitionManagerService recognitionF = recognition;   
425.      final LocationManagerService locationF = location;   
426.   
427.      // We now tell the activity manager it is okay to run third party   
428.      // code.  It will call back into us once it has gotten to the state   
429.      // where third party code can really run (but before it has actually   
430.      // started launching the initial applications), for us to complete our   
431.      // initialization.   
432.      ((ActivityManagerService)ActivityManagerNative.getDefault())   
433.              .systemReady(new Runnable() {   
434.          public void run() {   
435.              Slog.i(TAG, “Making services ready”);   
436.   
437.              if (statusBarF != null) statusBarF.systemReady2();   
438.              if (batteryF != null) batteryF.systemReady();   
439.              if (connectivityF != null) connectivityF.systemReady();   
440.              if (dockF != null) dockF.systemReady();   
441.              if (usbF != null) usbF.systemReady();   
442.              if (uiModeF != null) uiModeF.systemReady();   
443.              if (recognitionF != null) recognitionF.systemReady();   
444.              Watchdog.getInstance().start();   
445.   
446.              // It is now okay to let the various system services start their   
447.              // third party code…   
448.   
449.              if (appWidgetF != null) appWidgetF.systemReady(safeMode);   
450.              if (wallpaperF != null) wallpaperF.systemReady();   
451.              if (immF != null) immF.systemReady();   
452.              if (locationF != null) locationF.systemReady();   
453.              if (throttleF != null) throttleF.systemReady();   
454.          }   
455.      });   
456.   
457.      // For debug builds, log event loop stalls to dropbox for analysis.   
458.      if (StrictMode.conditionallyEnableDebugLogging()) {   
459.          Slog.i(TAG, “Enabled StrictMode for system server main thread.”);   
460.      }   
461.   
462.      Looper.loop();   
463.      Slog.d(TAG, “System ServerThread is exiting!”);   
464.  }  

public void run() { EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_SYSTEM_RUN, SystemClock.uptimeMillis()); Looper.prepare(); android.os.Process.setThreadPriority( android.os.Process.THREAD_PRIORITY_FOREGROUND); BinderInternal.disableBackgroundScheduling(true); android.os.Process.setCanSelfBackground(false); // Check whether we failed to shut down last time we tried. { final String shutdownAction = SystemProperties.get( ShutdownThread.SHUTDOWN_ACTION_PROPERTY, “”); if (shutdownAction != null && shutdownAction.length() > 0) { boolean reboot = (shutdownAction.charAt(0) == ‘1’); final String reason; if (shutdownAction.length() > 1) { reason = shutdownAction.substring(1, shutdownAction.length()); } else { reason = null; } ShutdownThread.rebootOrShutdown(reboot, reason); } } String factoryTestStr = SystemProperties.get(“ro.factorytest”); int factoryTest = “”.equals(factoryTestStr) ? SystemServer.FACTORY_TEST_OFF : Integer.parseInt(factoryTestStr); LightsService lights = null; PowerManagerService power = null; BatteryService battery = null; ConnectivityService connectivity = null; IPackageManager pm = null; Context context = null; WindowManagerService wm = null; BluetoothService bluetooth = null; BluetoothA2dpService bluetoothA2dp = null; HeadsetObserver headset = null; DockObserver dock = null; UsbService usb = null; UiModeManagerService uiMode = null; RecognitionManagerService recognition = null; ThrottleService throttle = null; // Critical services… try { Slog.i(TAG, “Entropy Service”); ServiceManager.addService(“entropy”, new EntropyService()); Slog.i(TAG, “Power Manager”); power = new PowerManagerService(); ServiceManager.addService(Context.POWER_SERVICE, power); Slog.i(TAG, “Activity Manager”); context = ActivityManagerService.main(factoryTest); Slog.i(TAG, “Telephony Registry”); ServiceManager.addService(“telephony.registry”, new TelephonyRegistry(context)); AttributeCache.init(context); Slog.i(TAG, “Package Manager”); pm = PackageManagerService.main(context, factoryTest != SystemServer.FACTORY_TEST_OFF); ActivityManagerService.setSystemProcess(); mContentResolver = context.getContentResolver(); // The AccountManager must come before the ContentService try { Slog.i(TAG, “Account Manager”); ServiceManager.addService(Context.ACCOUNT_SERVICE, new AccountManagerService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting Account Manager”, e); } Slog.i(TAG, “Content Manager”); ContentService.main(context, factoryTest == SystemServer.FACTORY_TEST_LOW_LEVEL); Slog.i(TAG, “System Content Providers”); ActivityManagerService.installSystemProviders(); Slog.i(TAG, “Battery Service”); battery = new BatteryService(context); ServiceManager.addService(“battery”, battery); Slog.i(TAG, “Lights Service”); lights = new LightsService(context); Slog.i(TAG, “Vibrator Service”); ServiceManager.addService(“vibrator”, new VibratorService(context)); // only initialize the power service after we have started the // lights service, content providers and the battery service. power.init(context, lights, ActivityManagerService.getDefault(), battery); Slog.i(TAG, “Alarm Manager”); AlarmManagerService alarm = new AlarmManagerService(context); ServiceManager.addService(Context.ALARM_SERVICE, alarm); Slog.i(TAG, “Init Watchdog”); Watchdog.getInstance().init(context, battery, power, alarm, ActivityManagerService.self()); Slog.i(TAG, “Window Manager”); wm = WindowManagerService.main(context, power, factoryTest != SystemServer.FACTORY_TEST_LOW_LEVEL); ServiceManager.addService(Context.WINDOW_SERVICE, wm); ((ActivityManagerService)ServiceManager.getService(“activity”)) .setWindowManager(wm); // 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 (SystemProperties.get(“ro.kernel.qemu”).equals(“1”)) { Slog.i(TAG, “Registering null Bluetooth Service (emulator)”); ServiceManager.addService(BluetoothAdapter.BLUETOOTH_SERVICE, null); } else if (factoryTest == SystemServer.FACTORY_TEST_LOW_LEVEL) { Slog.i(TAG, “Registering null Bluetooth Service (factory test)”); ServiceManager.addService(BluetoothAdapter.BLUETOOTH_SERVICE, null); } else { Slog.i(TAG, “Bluetooth Service”); bluetooth = new BluetoothService(context); ServiceManager.addService(BluetoothAdapter.BLUETOOTH_SERVICE, bluetooth); bluetooth.initAfterRegistration(); bluetoothA2dp = new BluetoothA2dpService(context, bluetooth); ServiceManager.addService(BluetoothA2dpService.BLUETOOTH_A2DP_SERVICE, bluetoothA2dp); int bluetoothOn = Settings.Secure.getInt(mContentResolver, Settings.Secure.BLUETOOTH_ON, 0); if (bluetoothOn > 0) { bluetooth.enable(); } } } catch (RuntimeException e) { Slog.e(“System”, “Failure starting core service”, e); } DevicePolicyManagerService devicePolicy = null; StatusBarManagerService statusBar = null; InputMethodManagerService imm = null; AppWidgetService appWidget = null; NotificationManagerService notification = null; WallpaperManagerService wallpaper = null; LocationManagerService location = null; if (factoryTest != SystemServer.FACTORY_TEST_LOW_LEVEL) { try { Slog.i(TAG, “Device Policy”); devicePolicy = new DevicePolicyManagerService(context); ServiceManager.addService(Context.DEVICE_POLICY_SERVICE, devicePolicy); } catch (Throwable e) { Slog.e(TAG, “Failure starting DevicePolicyService”, e); } try { Slog.i(TAG, “Status Bar”); statusBar = new StatusBarManagerService(context); ServiceManager.addService(Context.STATUS_BAR_SERVICE, statusBar); } catch (Throwable e) { Slog.e(TAG, “Failure starting StatusBarManagerService”, e); } try { Slog.i(TAG, “Clipboard Service”); ServiceManager.addService(Context.CLIPBOARD_SERVICE, new ClipboardService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting Clipboard Service”, e); } try { Slog.i(TAG, “Input Method Service”); imm = new InputMethodManagerService(context, statusBar); ServiceManager.addService(Context.INPUT_METHOD_SERVICE, imm); } catch (Throwable e) { Slog.e(TAG, “Failure starting Input Manager Service”, e); } try { Slog.i(TAG, “NetStat Service”); ServiceManager.addService(“netstat”, new NetStatService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting NetStat Service”, e); } try { Slog.i(TAG, “NetworkManagement Service”); ServiceManager.addService( Context.NETWORKMANAGEMENT_SERVICE, NetworkManagementService.create(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting NetworkManagement Service”, e); } try { Slog.i(TAG, “Connectivity Service”); connectivity = ConnectivityService.getInstance(context); ServiceManager.addService(Context.CONNECTIVITY_SERVICE, connectivity); } catch (Throwable e) { Slog.e(TAG, “Failure starting Connectivity Service”, e); } try { Slog.i(TAG, “Throttle Service”); throttle = new ThrottleService(context); ServiceManager.addService( Context.THROTTLE_SERVICE, throttle); } catch (Throwable e) { Slog.e(TAG, “Failure starting ThrottleService”, e); } try { Slog.i(TAG, “Accessibility Manager”); ServiceManager.addService(Context.ACCESSIBILITY_SERVICE, new AccessibilityManagerService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting Accessibility Manager”, e); } try { /* * NotificationManagerService is dependant on MountService, * (for media / usb notifications) so we must start MountService first. */ Slog.i(TAG, “Mount Service”); ServiceManager.addService(“mount”, new MountService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting Mount Service”, e); } try { Slog.i(TAG, “Notification Manager”); notification = new NotificationManagerService(context, statusBar, lights); ServiceManager.addService(Context.NOTIFICATION_SERVICE, notification); } catch (Throwable e) { Slog.e(TAG, “Failure starting Notification Manager”, e); } try { Slog.i(TAG, “Device Storage Monitor”); ServiceManager.addService(DeviceStorageMonitorService.SERVICE, new DeviceStorageMonitorService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting DeviceStorageMonitor service”, e); } try { Slog.i(TAG, “Location Manager”); location = new LocationManagerService(context); ServiceManager.addService(Context.LOCATION_SERVICE, location); } catch (Throwable e) { Slog.e(TAG, “Failure starting Location Manager”, e); } try { Slog.i(TAG, “Search Service”); ServiceManager.addService(Context.SEARCH_SERVICE, new SearchManagerService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting Search Service”, e); } if (INCLUDE_DEMO) { Slog.i(TAG, “Installing demo data…”); (new DemoThread(context)).start(); } try { Slog.i(TAG, “DropBox Service”); ServiceManager.addService(Context.DROPBOX_SERVICE, new DropBoxManagerService(context, new File(“/data/system/dropbox”))); } catch (Throwable e) { Slog.e(TAG, “Failure starting DropBoxManagerService”, e); } try { Slog.i(TAG, “Wallpaper Service”); wallpaper = new WallpaperManagerService(context); ServiceManager.addService(Context.WALLPAPER_SERVICE, wallpaper); } catch (Throwable e) { Slog.e(TAG, “Failure starting Wallpaper Service”, e); } try { Slog.i(TAG, “Audio Service”); ServiceManager.addService(Context.AUDIO_SERVICE, new AudioService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting Audio Service”, e); } try { Slog.i(TAG, “Headset Observer”); // Listen for wired headset changes headset = new HeadsetObserver(context); } catch (Throwable e) { Slog.e(TAG, “Failure starting HeadsetObserver”, e); } try { Slog.i(TAG, “Dock Observer”); // Listen for dock station changes dock = new DockObserver(context, power); } catch (Throwable e) { Slog.e(TAG, “Failure starting DockObserver”, e); } try { Slog.i(TAG, “USB Service”); // Listen for USB changes usb = new UsbService(context); ServiceManager.addService(Context.USB_SERVICE, usb); } catch (Throwable e) { Slog.e(TAG, “Failure starting UsbService”, e); } try { Slog.i(TAG, “UI Mode Manager Service”); // Listen for UI mode changes uiMode = new UiModeManagerService(context); } catch (Throwable e) { Slog.e(TAG, “Failure starting UiModeManagerService”, e); } try { Slog.i(TAG, “Backup Service”); ServiceManager.addService(Context.BACKUP_SERVICE, new BackupManagerService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting Backup Service”, e); } try { Slog.i(TAG, “AppWidget Service”); appWidget = new AppWidgetService(context); ServiceManager.addService(Context.APPWIDGET_SERVICE, appWidget); } catch (Throwable e) { Slog.e(TAG, “Failure starting AppWidget Service”, e); } try { Slog.i(TAG, “Recognition Service”); recognition = new RecognitionManagerService(context); } catch (Throwable e) { Slog.e(TAG, “Failure starting Recognition Service”, e); } try { Slog.i(TAG, “DiskStats Service”); ServiceManager.addService(“diskstats”, new DiskStatsService(context)); } catch (Throwable e) { Slog.e(TAG, “Failure starting DiskStats Service”, e); } } // make sure the ADB_ENABLED setting value matches the secure property value Settings.Secure.putInt(mContentResolver, Settings.Secure.ADB_ENABLED, “1”.equals(SystemProperties.get(“persist.service.adb.enable”)) ? 1 : 0); // register observer to listen for settings changes mContentResolver.registerContentObserver(Settings.Secure.getUriFor(Settings.Secure.ADB_ENABLED), false, new AdbSettingsObserver()); // Before things start rolling, be sure we have decided whether // we are in safe mode. final boolean safeMode = wm.detectSafeMode(); if (safeMode) { try { ActivityManagerNative.getDefault().enterSafeMode(); // Post the safe mode state in the Zygote class Zygote.systemInSafeMode = true; // Disable the JIT for the system_server process VMRuntime.getRuntime().disableJitCompilation(); } catch (RemoteException e) { } } else { // Enable the JIT for the system_server process VMRuntime.getRuntime().startJitCompilation(); } // It is now time to start up the app processes… if (devicePolicy != null) { devicePolicy.systemReady(); } if (notification != null) { notification.systemReady(); } if (statusBar != null) { statusBar.systemReady(); } wm.systemReady(); power.systemReady(); try { pm.systemReady(); } catch (RemoteException e) { } // These are needed to propagate to the runnable below. final StatusBarManagerService statusBarF = statusBar; final BatteryService batteryF = battery; final ConnectivityService connectivityF = connectivity; final DockObserver dockF = dock; final UsbService usbF = usb; final ThrottleService throttleF = throttle; final UiModeManagerService uiModeF = uiMode; final AppWidgetService appWidgetF = appWidget; final WallpaperManagerService wallpaperF = wallpaper; final InputMethodManagerService immF = imm; final RecognitionManagerService recognitionF = recognition; final LocationManagerService locationF = location; // 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. ((ActivityManagerService)ActivityManagerNative.getDefault()) .systemReady(new Runnable() { public void run() { Slog.i(TAG, “Making services ready”); if (statusBarF != null) statusBarF.systemReady2(); if (batteryF != null) batteryF.systemReady(); if (connectivityF != null) connectivityF.systemReady(); if (dockF != null) dockF.systemReady(); if (usbF != null) usbF.systemReady(); if (uiModeF != null) uiModeF.systemReady(); if (recognitionF != null) recognitionF.systemReady(); Watchdog.getInstance().start(); // It is now okay to let the various system services start their // third party code… if (appWidgetF != null) appWidgetF.systemReady(safeMode); if (wallpaperF != null) wallpaperF.systemReady(); if (immF != null) immF.systemReady(); if (locationF != null) locationF.systemReady(); if (throttleF != null) throttleF.systemReady(); } }); // For debug builds, log event loop stalls to dropbox for analysis. if (StrictMode.conditionallyEnableDebugLogging()) { Slog.i(TAG, “Enabled StrictMode for system server main thread.”); } Looper.loop(); Slog.d(TAG, “System ServerThread is exiting!”); }

这里启动的没一个进程都作为一个Dalvik线程而存在于SystemServer进程里面。