SensorService中Binder案例
- 1、FWK实际操作在Native层
- 2、Native层中代码实现Bn/Bp端
- 2.1 代码实现Bn端
- 2.2 代码实现Bp端
- 2.2.1 模板interface_cast
android12-release
1、FWK实际操作在Native层
SensorService.java
实际操作Native层SensorService.cpp
;对应Bn服务端。
应用获取Context.SEARCH_SERVICE
实际操作Native层SensorManager.cpp
;对应Bp客户端。
frameworks/base/services/core/java/com/android/server/sensors/SensorService.java
public SensorService(Context ctx) {super(ctx);synchronized (mLock) {mSensorServiceStart = SystemServerInitThreadPool.submit(() -> {TimingsTraceAndSlog traceLog = TimingsTraceAndSlog.newAsyncLog();traceLog.traceBegin(START_NATIVE_SENSOR_SERVICE);long ptr = startSensorServiceNative(new ProximityListenerDelegate());synchronized (mLock) {mPtr = ptr;}traceLog.traceEnd();}, START_NATIVE_SENSOR_SERVICE);}
}@Override
public void onStart() {LocalServices.addService(SensorManagerInternal.class, new LocalService());
}
frameworks/base/core/java/android/hardware/SystemSensorManager.java
/** {@hide} */
public SystemSensorManager(Context context, Looper mainLooper) {synchronized (sLock) {if (!sNativeClassInited) {sNativeClassInited = true;nativeClassInit();}}mMainLooper = mainLooper;ApplicationInfo appInfo = context.getApplicationInfo();mTargetSdkLevel = appInfo.targetSdkVersion;mContext = context;mNativeInstance = nativeCreate(context.getOpPackageName());mIsPackageDebuggable = (0 != (appInfo.flags & ApplicationInfo.FLAG_DEBUGGABLE));PackageManager packageManager = context.getPackageManager();mHasHighSamplingRateSensorsPermission =(PERMISSION_GRANTED == packageManager.checkPermission(HIGH_SAMPLING_RATE_SENSORS_PERMISSION,appInfo.packageName));// initialize the sensor listfor (int index = 0;; ++index) {Sensor sensor = new Sensor();if (!nativeGetSensorAtIndex(mNativeInstance, sensor, index)) break;mFullSensorsList.add(sensor);mHandleToSensor.put(sensor.getHandle(), sensor);}
}
2、Native层中代码实现Bn/Bp端
ServiceManager
中添加"sensorservice"
frameworks/base/services/core/jni/com_android_server_sensor_SensorService.cpp
NativeSensorService::NativeSensorService(JNIEnv* env, jobject listener): mProximityActiveListenerDelegate(new ProximityActiveListenerDelegate(env, listener)) {if (base::GetBoolProperty("system_init.startsensorservice", true)) {sp<IServiceManager> sm(defaultServiceManager());mService = new SensorService();sm->addService(String16(SensorService::getServiceName()), mService,false /* allowIsolated */, IServiceManager::DUMP_FLAG_PRIORITY_CRITICAL);}
}
2.1 代码实现Bn端
SensorService
继承BnSensorServer
,实现onTransact
方法一边Bp客户端调用,Code标签
对应调用方法,Parcel& data
参数,Parcel* reply
接收返回值,flags = 0
存在默认值。
frameworks/native/libs/sensor/include/sensor/ISensorServer.h
class BnSensorServer : public BnInterface<ISensorServer>
{
public:virtual status_t shellCommand(int in, int out, int err,Vector<String16>& args) = 0;virtual status_t onTransact( uint32_t code,const Parcel& data,Parcel* reply,uint32_t flags = 0);
};
frameworks/native/libs/sensor/ISensorServer.cpp
enum {GET_SENSOR_LIST = IBinder::FIRST_CALL_TRANSACTION,CREATE_SENSOR_EVENT_CONNECTION,ENABLE_DATA_INJECTION,GET_DYNAMIC_SENSOR_LIST,CREATE_SENSOR_DIRECT_CONNECTION,SET_OPERATION_PARAMETER,
};status_t BnSensorServer::onTransact(uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
{switch(code) {case GET_SENSOR_LIST: {CHECK_INTERFACE(ISensorServer, data, reply);const String16& opPackageName = data.readString16();Vector<Sensor> v(getSensorList(opPackageName));size_t n = v.size();reply->writeUint32(static_cast<uint32_t>(n));for (size_t i = 0; i < n; i++) {reply->write(v[i]);}return NO_ERROR;}case CREATE_SENSOR_EVENT_CONNECTION: {CHECK_INTERFACE(ISensorServer, data, reply);String8 packageName = data.readString8();int32_t mode = data.readInt32();const String16& opPackageName = data.readString16();const String16& attributionTag = data.readString16();sp<ISensorEventConnection> connection(createSensorEventConnection(packageName, mode,opPackageName, attributionTag));reply->writeStrongBinder(IInterface::asBinder(connection));return NO_ERROR;}case ENABLE_DATA_INJECTION: {CHECK_INTERFACE(ISensorServer, data, reply);int32_t ret = isDataInjectionEnabled();reply->writeInt32(static_cast<int32_t>(ret));return NO_ERROR;}case GET_DYNAMIC_SENSOR_LIST: {CHECK_INTERFACE(ISensorServer, data, reply);const String16& opPackageName = data.readString16();Vector<Sensor> v(getDynamicSensorList(opPackageName));size_t n = v.size();reply->writeUint32(static_cast<uint32_t>(n));for (size_t i = 0; i < n; i++) {reply->write(v[i]);}return NO_ERROR;}case CREATE_SENSOR_DIRECT_CONNECTION: {CHECK_INTERFACE(ISensorServer, data, reply);const String16& opPackageName = data.readString16();uint32_t size = data.readUint32();int32_t type = data.readInt32();int32_t format = data.readInt32();native_handle_t *resource = data.readNativeHandle();// Avoid a crash in native_handle_close if resource is nullptrif (resource == nullptr) {return BAD_VALUE;}sp<ISensorEventConnection> ch =createSensorDirectConnection(opPackageName, size, type, format, resource);native_handle_close(resource);native_handle_delete(resource);reply->writeStrongBinder(IInterface::asBinder(ch));return NO_ERROR;}case SET_OPERATION_PARAMETER: {CHECK_INTERFACE(ISensorServer, data, reply);int32_t handle;int32_t type;Vector<float> floats;Vector<int32_t> ints;uint32_t count;handle = data.readInt32();type = data.readInt32();count = data.readUint32();if (count > (data.dataAvail() / sizeof(float))) {return BAD_VALUE;}floats.resize(count);for (auto &i : floats) {i = data.readFloat();}count = data.readUint32();if (count > (data.dataAvail() / sizeof(int32_t))) {return BAD_VALUE;}ints.resize(count);for (auto &i : ints) {i = data.readInt32();}int32_t ret = setOperationParameter(handle, type, floats, ints);reply->writeInt32(ret);return NO_ERROR;}case SHELL_COMMAND_TRANSACTION: {int in = data.readFileDescriptor();int out = data.readFileDescriptor();int err = data.readFileDescriptor();int argc = data.readInt32();Vector<String16> args;for (int i = 0; i < argc && data.dataAvail() > 0; i++) {args.add(data.readString16());}sp<IBinder> unusedCallback;sp<IResultReceiver> resultReceiver;status_t status;if ((status = data.readNullableStrongBinder(&unusedCallback)) != NO_ERROR) {return status;}if ((status = data.readNullableStrongBinder(&resultReceiver)) != NO_ERROR) {return status;}status = shellCommand(in, out, err, args);if (resultReceiver != nullptr) {resultReceiver->send(status);}return NO_ERROR;}}return BBinder::onTransact(code, data, reply, flags);
}
2.2 代码实现Bp端
应用获取
Context.SEARCH_SERVICE
实际操作Native层SensorManager.cpp
;对应Bp客户端获取查看 Binder系列2-ServiceManager 中模板interface_cast
=> 模板::android::sp<Bp##INTERFACE>::make(obj)
Bp端中方法如getSensorList()
,通过remote()->transact(GET_SENSOR_LIST, data, &reply);
最终调用到Bn端的onTransact
方法,GET_SENSOR_LIST
作为Code标签
调用对应方法,Parcel& data
参数,Parcel* reply
接收返回值,flags = 0
有默认值。
frameworks/native/libs/sensor/include/sensor/ISensorServer.h
frameworks/native/libs/sensor/ISensorServer.cpp
enum {GET_SENSOR_LIST = IBinder::FIRST_CALL_TRANSACTION,CREATE_SENSOR_EVENT_CONNECTION,ENABLE_DATA_INJECTION,GET_DYNAMIC_SENSOR_LIST,CREATE_SENSOR_DIRECT_CONNECTION,SET_OPERATION_PARAMETER,
};class BpSensorServer : public BpInterface<ISensorServer>
{
public:explicit BpSensorServer(const sp<IBinder>& impl): BpInterface<ISensorServer>(impl){}virtual ~BpSensorServer();virtual Vector<Sensor> getSensorList(const String16& opPackageName){Parcel data, reply;data.writeInterfaceToken(ISensorServer::getInterfaceDescriptor());data.writeString16(opPackageName);remote()->transact(GET_SENSOR_LIST, data, &reply);Sensor s;Vector<Sensor> v;uint32_t n = reply.readUint32();v.setCapacity(n);while (n) {n--;reply.read(s);v.add(s);}return v;}virtual Vector<Sensor> getDynamicSensorList(const String16& opPackageName){Parcel data, reply;data.writeInterfaceToken(ISensorServer::getInterfaceDescriptor());data.writeString16(opPackageName);remote()->transact(GET_DYNAMIC_SENSOR_LIST, data, &reply);Sensor s;Vector<Sensor> v;uint32_t n = reply.readUint32();v.setCapacity(n);while (n) {n--;reply.read(s);v.add(s);}return v;}virtual sp<ISensorEventConnection> createSensorEventConnection(const String8& packageName,int mode, const String16& opPackageName, const String16& attributionTag){Parcel data, reply;data.writeInterfaceToken(ISensorServer::getInterfaceDescriptor());data.writeString8(packageName);data.writeInt32(mode);data.writeString16(opPackageName);data.writeString16(attributionTag);remote()->transact(CREATE_SENSOR_EVENT_CONNECTION, data, &reply);return interface_cast<ISensorEventConnection>(reply.readStrongBinder());}virtual int isDataInjectionEnabled() {Parcel data, reply;data.writeInterfaceToken(ISensorServer::getInterfaceDescriptor());remote()->transact(ENABLE_DATA_INJECTION, data, &reply);return reply.readInt32();}virtual sp<ISensorEventConnection> createSensorDirectConnection(const String16& opPackageName,uint32_t size, int32_t type, int32_t format, const native_handle_t *resource) {Parcel data, reply;data.writeInterfaceToken(ISensorServer::getInterfaceDescriptor());data.writeString16(opPackageName);data.writeUint32(size);data.writeInt32(type);data.writeInt32(format);data.writeNativeHandle(resource);remote()->transact(CREATE_SENSOR_DIRECT_CONNECTION, data, &reply);return interface_cast<ISensorEventConnection>(reply.readStrongBinder());}virtual int setOperationParameter(int32_t handle, int32_t type,const Vector<float> &floats,const Vector<int32_t> &ints) {Parcel data, reply;data.writeInterfaceToken(ISensorServer::getInterfaceDescriptor());data.writeInt32(handle);data.writeInt32(type);data.writeUint32(static_cast<uint32_t>(floats.size()));for (auto i : floats) {data.writeFloat(i);}data.writeUint32(static_cast<uint32_t>(ints.size()));for (auto i : ints) {data.writeInt32(i);}remote()->transact(SET_OPERATION_PARAMETER, data, &reply);return reply.readInt32();}
};// Out-of-line virtual method definition to trigger vtable emission in this
// translation unit (see clang warning -Wweak-vtables)
BpSensorServer::~BpSensorServer() {}
2.2.1 模板interface_cast
对应Bp客户端获取查看 Binder系列2-ServiceManager 中
模板interface_cast
=> 模板::android::sp<Bp##INTERFACE>::make(obj)
frameworks/native/libs/binder/include/binder/IServiceManager.h
template<typename INTERFACE>
status_t getService(const String16& name, sp<INTERFACE>* outService)
{const sp<IServiceManager> sm = defaultServiceManager();if (sm != nullptr) {*outService = interface_cast<INTERFACE>(sm->getService(name));if ((*outService) != nullptr) return NO_ERROR;}return NAME_NOT_FOUND;
}
frameworks/native/libs/binder/include/binder/IInterface.h
//... ...
template<typename INTERFACE>
inline sp<INTERFACE> interface_cast(const sp<IBinder>& obj)
{return INTERFACE::asInterface(obj);
}
//... ...static ::android::sp<I##INTERFACE> asInterface( \const ::android::sp<::android::IBinder>& obj); \
//... ...::android::sp<I##INTERFACE> I##INTERFACE::asInterface( \const ::android::sp<::android::IBinder>& obj) \{ \::android::sp<I##INTERFACE> intr; \if (obj != nullptr) { \intr = ::android::sp<I##INTERFACE>::cast( \obj->queryLocalInterface(I##INTERFACE::descriptor)); \if (intr == nullptr) { \intr = ::android::sp<Bp##INTERFACE>::make(obj); \} \} \return intr; \} \