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 list
for (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 nullptr
if (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; \
} \