Cubietruck---18.input子系统启动流程分析

一. Input 系统的初始化
1. InputManagerService是由SystemServer建立的
在frameworks/base/services/java/com/android/server/SystemServer.java中

1. class ServerThread extends Thread {
   
2.  @Override
   
3.     public void run() {
   
4.       HandlerThread wmHandlerThread = new HandlerThread("WindowManager");
   
5.       wmHandlerThread.start();
   
6.       Handler wmHandler = new Handler(wmHandlerThread.getLooper());
   
7.       context = ActivityManagerService.main(factoryTest);
   
8.      
   
9.       InputManagerService inputManager = null;
10.       //1.1 new的过程创建InputReader InputDispatcher和EventHub  
    
11.       inputManager = new InputManagerService(context, wmHandler);  
    
12.       inputManager.setWindowManagerCallbacks(wm.getInputMonitor());
    
13.       //1.2 start的过程:将InputReader与InputDispatcher的线程跑起来
    
14.       inputManager.start();                  
    
15.      
    
16.       display.setInputManager(inputManager);
    
17.      }
    
18. }

1.1 new的调用过程
SystemServer:: new InputManagerService
  --> InputManagerService构造函数
在frameworks/base/services/java/com/android/server/input/InputManagerService.java中

1. public InputManagerService(Context context, Handler handler) 
2. {
   
3.     this.mContext = context;
   
4.     this.mHandler = new InputManagerHandler(handler.getLooper());    
   
5.     mPtr = nativeInit(this, mContext, mHandler.getLooper().getQueue());
   
6. }

SystemServer:: new InputManagerService
  --> InputManagerService构造函数
    --> nativeInit     ;;通过jni调用
在frameworks/base/services/jni/com_android_server_input_InputManagerService.cpp 中

1. static jint nativeInit(JNIEnv* env, jclass clazz, jobject serviceObj, jobject contextObj, jobject messageQueueObj) 
2. {
   
3.     sp<MessageQueue> messageQueue = android_os_MessageQueue_getMessageQueue(env, messageQueueObj);
   
4.     NativeInputManager* im = new NativeInputManager(contextObj, serviceObj, messageQueue->getLooper());
   
5.     im->incStrong(serviceObj);
   
6.     return reinterpret_cast<jint>(im);
   
7. }

SystemServer:: new InputManagerService
  --> InputManagerService构造函数
    --> nativeInit     ;;通过jni调用NativeInputManager的构造
        --> NativeInputManager ;;new一个EventHub和InputManager
在frameworks/base/services/jni/com_android_server_input_InputManagerService.cpp中

1. NativeInputManager::NativeInputManager(jobject contextObj, jobject serviceObj, const sp<Looper>& looper) : mLooper(looper) 
2. {
   
3.     JNIEnv* env = jniEnv();
4.     mContextObj = env->NewGlobalRef(contextObj);
   
5.     mServiceObj = env->NewGlobalRef(serviceObj);
6.     AutoMutex _l(mLock);
   
7.     mLocked.systemUiVisibility = ASYSTEM_UI_VISIBILITY_STATUS_BAR_VISIBLE;
   
8.     mLocked.pointerSpeed = 0; 
   
9.     mLocked.pointerGesturesEnabled = true;
   
10.     mLocked.showTouches = false;
    
11. 
    
12.     sp<EventHub> eventHub = new EventHub();
    
13.     mInputManager = new InputManager(eventHub, this, this);
    
14. }

SystemServer:: new InputManagerService
  --> InputManagerService构造函数
    --> nativeInit         ;;通过jni调用NativeInputManager的构造
        --> NativeInputManager构造 ;;new一个EventHub和InputManager
          --> InputManager构造       ;;new InputDispatcher和InputReader及其线程
在frameworks/base/services/input/InputManager.cpp中
在InputManager的构造函数中,又建立了InputDispatcher和InputReader

1. InputManager::InputManager(const sp<EventHubInterface>& eventHub,
   
2.         const sp<InputReaderPolicyInterface>& readerPolicy,
   
3.         const sp<InputDispatcherPolicyInterface>& dispatcherPolicy) {
   
4.     mDispatcher = new InputDispatcher(dispatcherPolicy);
   
5.     mReader = new InputReader(eventHub, readerPolicy, mDispatcher);
   
6.     initialize();
   
7. }

同时又建立了InputDispatcher和InputReader各自的线程

1. void InputManager::initialize() {
   
2.     mReaderThread = new InputReaderThread(mReader);
   
3.     mDispatcherThread = new InputDispatcherThread(mDispatcher);
   
4. }

1.2 start的调用过程
SystemServer:: InputManagerService.start
  --> InputManagerService::start   ;;调用jni
在frameworks/base/services/java/com/android/server/input/InputManagerService.java中

1. public void start() {
   
2.     nativeStart(mPtr);
3. }

SystemServer:: InputManagerService.start
  --> InputManagerService::start   ;;调用jni
    --> nativeStart         ;;通过jni调用NativeInputManager的start
在frameworks/base/services/jni/com_android_server_input_InputManagerService.cpp 中

1. public void start() {
   
2.     nativeStart(mPtr);
   
3. }

SystemServer:: InputManagerService.start
  --> InputManagerService::start   ;;调用jni
    --> nativeStart         ;;通过jni调用NativeInputManager的start
        --> NativeInputManager::nativeStart ;;调用InputManager的start
在frameworks/base/services/jni/com_android_server_input_InputManagerService.cpp中

1. static void nativeStart(JNIEnv* env, jclass clazz, jint ptr) {
   
2.     NativeInputManager* im = reinterpret_cast<NativeInputManager*>(ptr);
   
3.     status_t result = im->getInputManager()->start();
   
4. }

SystemServer:: InputManagerService.start
  --> InputManagerService::start   ;;调用jni
    --> nativeStart         ;;通过jni调用NativeInputManager的start
        --> NativeInputManager::nativeStart ;;调用InputManager的start
          --> InputManager::start       ;;让InputDispatcher和InputReader的线程跑起来
在frameworks/base/services/input/InputManager.cpp中

1. status_t InputManager::start() {
   
2.     mDispatcherThread->run("InputDispatcher", PRIORITY_URGENT_DISPLAY);
3.     mReaderThread->run("InputReader", PRIORITY_URGENT_DISPLAY);
4.     return OK;
   
5. }