android Jelly Bean版本如何将camera service修改为强占式

实现强占式camera service，当某些应用（如手电筒）在后台打开camera后，当camera app open camera时可以强占被后台应用占有的camera.



 1. 修改CameraService.cpp (frameworks/av/services/camera/libcameraservice/)

 文件的connect()方法，将

 原来的

     Mutex::Autolock lock(mServiceLock);

     if (mClient[cameraId] != 0) {

         client = mClient[cameraId].promote();

         if (client != 0) {

             if (cameraClient->asBinder() == client->getCameraClient()->asBinder()) {

                 LOG1("CameraService::connect X (pid %d) (the same client)",

                      callingPid);

                 return client;

             } else {

                 ALOGW("CameraService::connect X (pid %d) rejected (existing client).",

                       callingPid);

                 return NULL;

             }

         }

         mClient[cameraId].clear();

     }

 修改为：

    

     if (mClient[cameraId] != 0) {

         client = mClient[cameraId].promote();

         if (client != 0) {

                 LOG1("CameraService::connect X (pid %d)  disconnect the old client", callingPid);

                client->disconnect();

         }

         mClient[cameraId].clear();

     }

    Mutex::Autolock lock(mServiceLock);

  

 2. 修改CameraClient.cpp(frameworks/av/services/camera/libcameraservice/)

 文件的disconnect()方法:

 将原来的：

     if (callingPid != mClientPid && callingPid != mServicePid) {

         ALOGW("different client - don't disconnect");

         return;

     }

 修改为：

     if (callingPid != mClientPid && callingPid != mServicePid) {

         ALOGW("different client but  preemptive camera service！ ");

         //return;

     }