services/sensorservice/SensorService.h - android_frameworks_native - Gitiles

 /*
  * Copyright (C) 2010 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #ifndef ANDROID_SENSOR_SERVICE_H
 #define ANDROID_SENSOR_SERVICE_H

 #include "SensorList.h"
 #include "RecentEventLogger.h"

 #include <android-base/macros.h>
 #include <binder/AppOpsManager.h>
 #include <binder/BinderService.h>
 #include <binder/IUidObserver.h>
 #include <cutils/compiler.h>
 #include <cutils/multiuser.h>
 #include <sensor/ISensorServer.h>
 #include <sensor/ISensorEventConnection.h>
 #include <sensor/Sensor.h>
 #include "android/hardware/BnSensorPrivacyListener.h"

 #include <utils/AndroidThreads.h>
 #include <utils/KeyedVector.h>
 #include <utils/Looper.h>
 #include <utils/SortedVector.h>
 #include <utils/String8.h>
 #include <utils/Vector.h>
 #include <utils/threads.h>

 #include <stdint.h>
 #include <sys/types.h>
 #include <unordered_map>
 #include <unordered_set>
 #include <vector>

 #if __clang__
 // Clang warns about SensorEventConnection::dump hiding BBinder::dump. The cause isn't fixable
 // without changing the API, so let's tell clang this is indeed intentional.
 #pragma clang diagnostic ignored "-Woverloaded-virtual"
 #endif

 // ---------------------------------------------------------------------------
 #define IGNORE_HARDWARE_FUSION  false
 #define DEBUG_CONNECTIONS   false
 // Max size is 100 KB which is enough to accept a batch of about 1000 events.
 #define MAX_SOCKET_BUFFER_SIZE_BATCHED (100 * 1024)
 // For older HALs which don't support batching, use a smaller socket buffer size.
 #define SOCKET_BUFFER_SIZE_NON_BATCHED (4 * 1024)

 #define SENSOR_REGISTRATIONS_BUF_SIZE 200

 namespace android {
 // ---------------------------------------------------------------------------
 class SensorInterface;

 class SensorService :
         public BinderService<SensorService>,
         public BnSensorServer,
         protected Thread
 {
     // nested class/struct for internal use
     class SensorEventConnection;
     class SensorDirectConnection;

 public:
     enum UidState {
       UID_STATE_ACTIVE = 0,
       UID_STATE_IDLE,
     };

     void cleanupConnection(SensorEventConnection* connection);
     void cleanupConnection(SensorDirectConnection* c);

     status_t enable(const sp<SensorEventConnection>& connection, int handle,
                     nsecs_t samplingPeriodNs,  nsecs_t maxBatchReportLatencyNs, int reservedFlags,
                     const String16& opPackageName);

     status_t disable(const sp<SensorEventConnection>& connection, int handle);

     status_t setEventRate(const sp<SensorEventConnection>& connection, int handle, nsecs_t ns,
                           const String16& opPackageName);

     status_t flushSensor(const sp<SensorEventConnection>& connection,
                          const String16& opPackageName);


     virtual status_t shellCommand(int in, int out, int err, Vector<String16>& args);

 private:
     friend class BinderService<SensorService>;

     // nested class/struct for internal use
     class ConnectionSafeAutolock;
     class SensorConnectionHolder;
     class SensorEventAckReceiver;
     class SensorRecord;
     class SensorRegistrationInfo;

     // Promoting a SensorEventConnection or SensorDirectConnection from wp to sp must be done with
     // mLock held, but destroying that sp must be done unlocked to avoid a race condition that
     // causes a deadlock (remote dies while we hold a local sp, then our decStrong() call invokes
     // the dtor -> cleanupConnection() tries to re-lock the mutex). This class ensures safe usage
     // by wrapping a Mutex::Autolock on SensorService's mLock, plus vectors that hold promoted sp<>
     // references until the lock is released, when they are safely destroyed.
     // All read accesses to the connection lists in mConnectionHolder must be done via this class.
     class ConnectionSafeAutolock final {
     public:
         // Returns a list of non-null promoted connection references
         const std::vector<sp<SensorEventConnection>>& getActiveConnections();
         const std::vector<sp<SensorDirectConnection>>& getDirectConnections();

     private:
         // Constructed via SensorConnectionHolder::lock()
         friend class SensorConnectionHolder;
         explicit ConnectionSafeAutolock(SensorConnectionHolder& holder, Mutex& mutex);
         DISALLOW_IMPLICIT_CONSTRUCTORS(ConnectionSafeAutolock);

         // NOTE: Order of these members is important, as the destructor for non-static members
         // get invoked in the reverse order of their declaration. Here we are relying on the
         // Autolock to be destroyed *before* the vectors, so the sp<> objects are destroyed without
         // the lock held, which avoids the deadlock.
         SensorConnectionHolder& mConnectionHolder;
         std::vector<std::vector<sp<SensorEventConnection>>> mReferencedActiveConnections;
         std::vector<std::vector<sp<SensorDirectConnection>>> mReferencedDirectConnections;
         Mutex::Autolock mAutolock;

         template<typename ConnectionType>
         const std::vector<sp<ConnectionType>>& getConnectionsHelper(
                 const SortedVector<wp<ConnectionType>>& connectionList,
                 std::vector<std::vector<sp<ConnectionType>>>* referenceHolder);
     };

     // Encapsulates the collection of active SensorEventConection and SensorDirectConnection
     // references. Write access is done through this class with mLock held, but all read access
     // must be routed through ConnectionSafeAutolock.
     class SensorConnectionHolder {
     public:
         void addEventConnectionIfNotPresent(const sp<SensorEventConnection>& connection);
         void removeEventConnection(const wp<SensorEventConnection>& connection);

         void addDirectConnection(const sp<SensorDirectConnection>& connection);
         void removeDirectConnection(const wp<SensorDirectConnection>& connection);

         // Pass in the mutex that protects this connection holder; acquires the lock and returns an
         // object that can be used to safely read the lists of connections
         ConnectionSafeAutolock lock(Mutex& mutex);

     private:
         friend class ConnectionSafeAutolock;
         SortedVector< wp<SensorEventConnection> > mActiveConnections;
         SortedVector< wp<SensorDirectConnection> > mDirectConnections;
     };

     // If accessing a sensor we need to make sure the UID has access to it. If
     // the app UID is idle then it cannot access sensors and gets no trigger
     // events, no on-change events, flush event behavior does not change, and
     // recurring events are the same as the first one delivered in idle state
     // emulating no sensor change. As soon as the app UID transitions to an
     // active state we will start reporting events as usual and vise versa. This
     // approach transparently handles observing sensors while the app UID transitions
     // between idle/active state avoiding to get stuck in a state receiving sensor
     // data while idle or not receiving sensor data while active.
     class UidPolicy : public BnUidObserver {
         public:
             explicit UidPolicy(wp<SensorService> service)
                     : mService(service) {}
             void registerSelf();
             void unregisterSelf();

             bool isUidActive(uid_t uid);

             void onUidGone(uid_t uid, bool disabled);
             void onUidActive(uid_t uid);
             void onUidIdle(uid_t uid, bool disabled);
             void onUidStateChanged(uid_t uid __unused, int32_t procState __unused,
                                    int64_t procStateSeq __unused, int32_t capability __unused) {}

             void addOverrideUid(uid_t uid, bool active);
             void removeOverrideUid(uid_t uid);
         private:
             bool isUidActiveLocked(uid_t uid);
             void updateOverrideUid(uid_t uid, bool active, bool insert);

             Mutex mUidLock;
             wp<SensorService> mService;
             std::unordered_set<uid_t> mActiveUids;
             std::unordered_map<uid_t, bool> mOverrideUids;
     };

     bool isUidActive(uid_t uid);

     // Sensor privacy allows a user to disable access to all sensors on the device. When
     // enabled sensor privacy will prevent all apps, including active apps, from accessing
     // sensors, they will not receive trigger nor on-change events, flush event behavior
     // does not change, and recurring events are the same as the first one delivered when
     // sensor privacy was enabled. All sensor direct connections will be stopped as well
     // and new direct connections will not be allowed while sensor privacy is enabled.
     // Once sensor privacy is disabled access to sensors will be restored for active
     // apps, previously stopped direct connections will be restarted, and new direct
     // connections will be allowed again.
     class SensorPrivacyPolicy : public hardware::BnSensorPrivacyListener {
         public:
             explicit SensorPrivacyPolicy(wp<SensorService> service) : mService(service) {}
             void registerSelf();
             void unregisterSelf();

             bool isSensorPrivacyEnabled();

             binder::Status onSensorPrivacyChanged(bool enabled);

         private:
             wp<SensorService> mService;
             std::atomic_bool mSensorPrivacyEnabled;
     };

     enum Mode {
        // The regular operating mode where any application can register/unregister/call flush on
        // sensors.
        NORMAL = 0,
        // This mode is only used for testing purposes. Not all HALs support this mode. In this mode,
        // the HAL ignores the sensor data provided by physical sensors and accepts the data that is
        // injected from the SensorService as if it were the real sensor data. This mode is primarily
        // used for testing various algorithms like vendor provided SensorFusion, Step Counter and
        // Step Detector etc. Typically in this mode, there will be a client (a
        // SensorEventConnection) which will be injecting sensor data into the HAL. Normal apps can
        // unregister and register for any sensor that supports injection. Registering to sensors
        // that do not support injection will give an error.  TODO(aakella) : Allow exactly one
        // client to inject sensor data at a time.
        DATA_INJECTION = 1,
        // This mode is used only for testing sensors. Each sensor can be tested in isolation with
        // the required sampling_rate and maxReportLatency parameters without having to think about
        // the data rates requested by other applications. End user devices are always expected to be
        // in NORMAL mode. When this mode is first activated, all active sensors from all connections
        // are disabled. Calling flush() will return an error. In this mode, only the requests from
        // selected apps whose package names are whitelisted are allowed (typically CTS apps).  Only
        // these apps can register/unregister/call flush() on sensors. If SensorService switches to
        // NORMAL mode again, all sensors that were previously registered to are activated with the
        // corresponding paramaters if the application hasn't unregistered for sensors in the mean
        // time.  NOTE: Non whitelisted app whose sensors were previously deactivated may still
        // receive events if a whitelisted app requests data from the same sensor.
        RESTRICTED = 2

       // State Transitions supported.
       //     RESTRICTED   <---  NORMAL   ---> DATA_INJECTION
       //                  --->           <---

       // Shell commands to switch modes in SensorService.
       // 1) Put SensorService in RESTRICTED mode with packageName .cts. If it is already in
       // restricted mode it is treated as a NO_OP (and packageName is NOT changed).
       //
       //     $ adb shell dumpsys sensorservice restrict .cts.
       //
       // 2) Put SensorService in DATA_INJECTION mode with packageName .xts. If it is already in
       // data_injection mode it is treated as a NO_OP (and packageName is NOT changed).
       //
       //     $ adb shell dumpsys sensorservice data_injection .xts.
       //
       // 3) Reset sensorservice back to NORMAL mode.
       //     $ adb shell dumpsys sensorservice enable
     };

     static const char* WAKE_LOCK_NAME;
     static char const* getServiceName() ANDROID_API { return "sensorservice"; }
     SensorService() ANDROID_API;
     virtual ~SensorService();

     virtual void onFirstRef();

     // Thread interface
     virtual bool threadLoop();

     // ISensorServer interface
     virtual Vector<Sensor> getSensorList(const String16& opPackageName);
     virtual Vector<Sensor> getDynamicSensorList(const String16& opPackageName);
     virtual sp<ISensorEventConnection> createSensorEventConnection(
             const String8& packageName,
             int requestedMode, const String16& opPackageName);
     virtual int isDataInjectionEnabled();
     virtual sp<ISensorEventConnection> createSensorDirectConnection(const String16& opPackageName,
             uint32_t size, int32_t type, int32_t format, const native_handle *resource);
     virtual int setOperationParameter(
             int32_t handle, int32_t type, const Vector<float> &floats, const Vector<int32_t> &ints);
     virtual status_t dump(int fd, const Vector<String16>& args);
     status_t dumpProtoLocked(int fd, ConnectionSafeAutolock* connLock) const;
     String8 getSensorName(int handle) const;
     bool isVirtualSensor(int handle) const;
     sp<SensorInterface> getSensorInterfaceFromHandle(int handle) const;
     bool isWakeUpSensor(int type) const;
     void recordLastValueLocked(sensors_event_t const* buffer, size_t count);
     static void sortEventBuffer(sensors_event_t* buffer, size_t count);
     const Sensor& registerSensor(SensorInterface* sensor,
                                  bool isDebug = false, bool isVirtual = false);
     const Sensor& registerVirtualSensor(SensorInterface* sensor, bool isDebug = false);
     const Sensor& registerDynamicSensorLocked(SensorInterface* sensor, bool isDebug = false);
     bool unregisterDynamicSensorLocked(int handle);
     status_t cleanupWithoutDisable(const sp<SensorEventConnection>& connection, int handle);
     status_t cleanupWithoutDisableLocked(const sp<SensorEventConnection>& connection, int handle);
     void cleanupAutoDisabledSensorLocked(const sp<SensorEventConnection>& connection,
             sensors_event_t const* buffer, const int count);
     static bool canAccessSensor(const Sensor& sensor, const char* operation,
             const String16& opPackageName);
     static bool hasPermissionForSensor(const Sensor& sensor);
     static int getTargetSdkVersion(const String16& opPackageName);
     // SensorService acquires a partial wakelock for delivering events from wake up sensors. This
     // method checks whether all the events from these wake up sensors have been delivered to the
     // corresponding applications, if yes the wakelock is released.
     void checkWakeLockState();
     void checkWakeLockStateLocked(ConnectionSafeAutolock* connLock);
     bool isWakeLockAcquired();
     bool isWakeUpSensorEvent(const sensors_event_t& event) const;

     sp<Looper> getLooper() const;

     // Reset mWakeLockRefCounts for all SensorEventConnections to zero. This may happen if
     // SensorService did not receive any acknowledgements from apps which have registered for
     // wake_up sensors.
     void resetAllWakeLockRefCounts();

     // Acquire or release wake_lock. If wake_lock is acquired, set the timeout in the looper to 5
     // seconds and wake the looper.
     void setWakeLockAcquiredLocked(bool acquire);

     // Send events from the event cache for this particular connection.
     void sendEventsFromCache(const sp<SensorEventConnection>& connection);

     // If SensorService is operating in RESTRICTED mode, only select whitelisted packages are
     // allowed to register for or call flush on sensors. Typically only cts test packages are
     // allowed.
     bool isWhiteListedPackage(const String8& packageName);

     // Returns true if a connection with the specified opPackageName has no access to sensors
     // in the RESTRICTED mode (i.e. the service is in RESTRICTED mode, and the package is not
     // whitelisted). mLock must be held to invoke this method.
     bool isOperationRestrictedLocked(const String16& opPackageName);

     // Reset the state of SensorService to NORMAL mode.
     status_t resetToNormalMode();
     status_t resetToNormalModeLocked();

     // Transforms the UUIDs for all the sensors into proper IDs.
     void makeUuidsIntoIdsForSensorList(Vector<Sensor> &sensorList) const;
     // Gets the appropriate ID from the given UUID.
     int32_t getIdFromUuid(const Sensor::uuid_t &uuid) const;
     // Either read from storage or create a new one.
     static bool initializeHmacKey();

     // Enable SCHED_FIFO priority for thread
     void enableSchedFifoMode();

     // Sets whether the given UID can get sensor data
     void onUidStateChanged(uid_t uid, UidState state);

     // Returns true if a connection with the given uid and opPackageName
     // currently has access to sensors.
     bool hasSensorAccess(uid_t uid, const String16& opPackageName);
     // Same as hasSensorAccess but with mLock held.
     bool hasSensorAccessLocked(uid_t uid, const String16& opPackageName);

     // Overrides the UID state as if it is idle
     status_t handleSetUidState(Vector<String16>& args, int err);
     // Clears the override for the UID state
     status_t handleResetUidState(Vector<String16>& args, int err);
     // Gets the UID state
     status_t handleGetUidState(Vector<String16>& args, int out, int err);
     // Prints the shell command help
     status_t printHelp(int out);

     // temporarily stops all active direct connections and disables all sensors
     void disableAllSensors();
     void disableAllSensorsLocked(ConnectionSafeAutolock* connLock);
     // restarts the previously stopped direct connections and enables all sensors
     void enableAllSensors();
     void enableAllSensorsLocked(ConnectionSafeAutolock* connLock);

     static uint8_t sHmacGlobalKey[128];
     static bool sHmacGlobalKeyIsValid;

     SensorServiceUtil::SensorList mSensors;
     status_t mInitCheck;

     // Socket buffersize used to initialize BitTube. This size depends on whether batching is
     // supported or not.
     uint32_t mSocketBufferSize;
     sp<Looper> mLooper;
     sp<SensorEventAckReceiver> mAckReceiver;

     // protected by mLock
     mutable Mutex mLock;
     DefaultKeyedVector<int, SensorRecord*> mActiveSensors;
     std::unordered_set<int> mActiveVirtualSensors;
     SensorConnectionHolder mConnectionHolder;
     bool mWakeLockAcquired;
     sensors_event_t *mSensorEventBuffer, *mSensorEventScratch;
     // WARNING: these SensorEventConnection instances must not be promoted to sp, except via
     // modification to add support for them in ConnectionSafeAutolock
     wp<const SensorEventConnection> * mMapFlushEventsToConnections;
     std::unordered_map<int, SensorServiceUtil::RecentEventLogger*> mRecentEvent;
     Mode mCurrentOperatingMode;

     // This packagaName is set when SensorService is in RESTRICTED or DATA_INJECTION mode. Only
     // applications with this packageName are allowed to activate/deactivate or call flush on
     // sensors. To run CTS this is can be set to ".cts." and only CTS tests will get access to
     // sensors.
     String8 mWhiteListedPackage;

     int mNextSensorRegIndex;
     Vector<SensorRegistrationInfo> mLastNSensorRegistrations;

     sp<UidPolicy> mUidPolicy;
     sp<SensorPrivacyPolicy> mSensorPrivacyPolicy;

     static AppOpsManager sAppOpsManager;
     static std::map<String16, int> sPackageTargetVersion;
     static Mutex sPackageTargetVersionLock;
     static String16 sSensorInterfaceDescriptorPrefix;
 };

 } // namespace android
 #endif // ANDROID_SENSOR_SERVICE_H
	/*
	* Copyright (C) 2010 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#ifndef ANDROID_SENSOR_SERVICE_H
	#define ANDROID_SENSOR_SERVICE_H

	#include "SensorList.h"
	#include "RecentEventLogger.h"

	#include <android-base/macros.h>
	#include <binder/AppOpsManager.h>
	#include <binder/BinderService.h>
	#include <binder/IUidObserver.h>
	#include <cutils/compiler.h>
	#include <cutils/multiuser.h>
	#include <sensor/ISensorServer.h>
	#include <sensor/ISensorEventConnection.h>
	#include <sensor/Sensor.h>
	#include "android/hardware/BnSensorPrivacyListener.h"

	#include <utils/AndroidThreads.h>
	#include <utils/KeyedVector.h>
	#include <utils/Looper.h>
	#include <utils/SortedVector.h>
	#include <utils/String8.h>
	#include <utils/Vector.h>
	#include <utils/threads.h>

	#include <stdint.h>
	#include <sys/types.h>
	#include <unordered_map>
	#include <unordered_set>
	#include <vector>

	#if __clang__
	// Clang warns about SensorEventConnection::dump hiding BBinder::dump. The cause isn't fixable
	// without changing the API, so let's tell clang this is indeed intentional.
	#pragma clang diagnostic ignored "-Woverloaded-virtual"
	#endif

	// ---------------------------------------------------------------------------
	#define IGNORE_HARDWARE_FUSION false
	#define DEBUG_CONNECTIONS false
	// Max size is 100 KB which is enough to accept a batch of about 1000 events.
	#define MAX_SOCKET_BUFFER_SIZE_BATCHED (100 * 1024)
	// For older HALs which don't support batching, use a smaller socket buffer size.
	#define SOCKET_BUFFER_SIZE_NON_BATCHED (4 * 1024)

	#define SENSOR_REGISTRATIONS_BUF_SIZE 200

	namespace android {
	// ---------------------------------------------------------------------------
	class SensorInterface;

	class SensorService :
	public BinderService<SensorService>,
	public BnSensorServer,
	protected Thread
	{
	// nested class/struct for internal use
	class SensorEventConnection;
	class SensorDirectConnection;

	public:
	enum UidState {
	UID_STATE_ACTIVE = 0,
	UID_STATE_IDLE,
	};

	void cleanupConnection(SensorEventConnection* connection);
	void cleanupConnection(SensorDirectConnection* c);

	status_t enable(const sp<SensorEventConnection>& connection, int handle,
	nsecs_t samplingPeriodNs, nsecs_t maxBatchReportLatencyNs, int reservedFlags,
	const String16& opPackageName);

	status_t disable(const sp<SensorEventConnection>& connection, int handle);

	status_t setEventRate(const sp<SensorEventConnection>& connection, int handle, nsecs_t ns,
	const String16& opPackageName);

	status_t flushSensor(const sp<SensorEventConnection>& connection,
	const String16& opPackageName);


	virtual status_t shellCommand(int in, int out, int err, Vector<String16>& args);

	private:
	friend class BinderService<SensorService>;

	// nested class/struct for internal use
	class ConnectionSafeAutolock;
	class SensorConnectionHolder;
	class SensorEventAckReceiver;
	class SensorRecord;
	class SensorRegistrationInfo;

	// Promoting a SensorEventConnection or SensorDirectConnection from wp to sp must be done with
	// mLock held, but destroying that sp must be done unlocked to avoid a race condition that
	// causes a deadlock (remote dies while we hold a local sp, then our decStrong() call invokes
	// the dtor -> cleanupConnection() tries to re-lock the mutex). This class ensures safe usage
	// by wrapping a Mutex::Autolock on SensorService's mLock, plus vectors that hold promoted sp<>
	// references until the lock is released, when they are safely destroyed.
	// All read accesses to the connection lists in mConnectionHolder must be done via this class.
	class ConnectionSafeAutolock final {
	public:
	// Returns a list of non-null promoted connection references
	const std::vector<sp<SensorEventConnection>>& getActiveConnections();
	const std::vector<sp<SensorDirectConnection>>& getDirectConnections();

	private:
	// Constructed via SensorConnectionHolder::lock()
	friend class SensorConnectionHolder;
	explicit ConnectionSafeAutolock(SensorConnectionHolder& holder, Mutex& mutex);
	DISALLOW_IMPLICIT_CONSTRUCTORS(ConnectionSafeAutolock);

	// NOTE: Order of these members is important, as the destructor for non-static members
	// get invoked in the reverse order of their declaration. Here we are relying on the
	// Autolock to be destroyed before the vectors, so the sp<> objects are destroyed without
	// the lock held, which avoids the deadlock.
	SensorConnectionHolder& mConnectionHolder;
	std::vector<std::vector<sp<SensorEventConnection>>> mReferencedActiveConnections;
	std::vector<std::vector<sp<SensorDirectConnection>>> mReferencedDirectConnections;
	Mutex::Autolock mAutolock;

	template<typename ConnectionType>
	const std::vector<sp<ConnectionType>>& getConnectionsHelper(
	const SortedVector<wp<ConnectionType>>& connectionList,
	std::vector<std::vector<sp<ConnectionType>>>* referenceHolder);
	};

	// Encapsulates the collection of active SensorEventConection and SensorDirectConnection
	// references. Write access is done through this class with mLock held, but all read access
	// must be routed through ConnectionSafeAutolock.
	class SensorConnectionHolder {
	public:
	void addEventConnectionIfNotPresent(const sp<SensorEventConnection>& connection);
	void removeEventConnection(const wp<SensorEventConnection>& connection);

	void addDirectConnection(const sp<SensorDirectConnection>& connection);
	void removeDirectConnection(const wp<SensorDirectConnection>& connection);

	// Pass in the mutex that protects this connection holder; acquires the lock and returns an
	// object that can be used to safely read the lists of connections
	ConnectionSafeAutolock lock(Mutex& mutex);

	private:
	friend class ConnectionSafeAutolock;
	SortedVector< wp<SensorEventConnection> > mActiveConnections;
	SortedVector< wp<SensorDirectConnection> > mDirectConnections;
	};

	// If accessing a sensor we need to make sure the UID has access to it. If
	// the app UID is idle then it cannot access sensors and gets no trigger
	// events, no on-change events, flush event behavior does not change, and
	// recurring events are the same as the first one delivered in idle state
	// emulating no sensor change. As soon as the app UID transitions to an
	// active state we will start reporting events as usual and vise versa. This
	// approach transparently handles observing sensors while the app UID transitions
	// between idle/active state avoiding to get stuck in a state receiving sensor
	// data while idle or not receiving sensor data while active.
	class UidPolicy : public BnUidObserver {
	public:
	explicit UidPolicy(wp<SensorService> service)
	: mService(service) {}
	void registerSelf();
	void unregisterSelf();

	bool isUidActive(uid_t uid);

	void onUidGone(uid_t uid, bool disabled);
	void onUidActive(uid_t uid);
	void onUidIdle(uid_t uid, bool disabled);
	void onUidStateChanged(uid_t uid __unused, int32_t procState __unused,
	int64_t procStateSeq __unused, int32_t capability __unused) {}

	void addOverrideUid(uid_t uid, bool active);
	void removeOverrideUid(uid_t uid);
	private:
	bool isUidActiveLocked(uid_t uid);
	void updateOverrideUid(uid_t uid, bool active, bool insert);

	Mutex mUidLock;
	wp<SensorService> mService;
	std::unordered_set<uid_t> mActiveUids;
	std::unordered_map<uid_t, bool> mOverrideUids;
	};

	bool isUidActive(uid_t uid);

	// Sensor privacy allows a user to disable access to all sensors on the device. When
	// enabled sensor privacy will prevent all apps, including active apps, from accessing
	// sensors, they will not receive trigger nor on-change events, flush event behavior
	// does not change, and recurring events are the same as the first one delivered when
	// sensor privacy was enabled. All sensor direct connections will be stopped as well
	// and new direct connections will not be allowed while sensor privacy is enabled.
	// Once sensor privacy is disabled access to sensors will be restored for active
	// apps, previously stopped direct connections will be restarted, and new direct
	// connections will be allowed again.
	class SensorPrivacyPolicy : public hardware::BnSensorPrivacyListener {
	public:
	explicit SensorPrivacyPolicy(wp<SensorService> service) : mService(service) {}
	void registerSelf();
	void unregisterSelf();

	bool isSensorPrivacyEnabled();

	binder::Status onSensorPrivacyChanged(bool enabled);

	private:
	wp<SensorService> mService;
	std::atomic_bool mSensorPrivacyEnabled;
	};

	enum Mode {
	// The regular operating mode where any application can register/unregister/call flush on
	// sensors.
	NORMAL = 0,
	// This mode is only used for testing purposes. Not all HALs support this mode. In this mode,
	// the HAL ignores the sensor data provided by physical sensors and accepts the data that is
	// injected from the SensorService as if it were the real sensor data. This mode is primarily
	// used for testing various algorithms like vendor provided SensorFusion, Step Counter and
	// Step Detector etc. Typically in this mode, there will be a client (a
	// SensorEventConnection) which will be injecting sensor data into the HAL. Normal apps can
	// unregister and register for any sensor that supports injection. Registering to sensors
	// that do not support injection will give an error. TODO(aakella) : Allow exactly one
	// client to inject sensor data at a time.
	DATA_INJECTION = 1,
	// This mode is used only for testing sensors. Each sensor can be tested in isolation with
	// the required sampling_rate and maxReportLatency parameters without having to think about
	// the data rates requested by other applications. End user devices are always expected to be
	// in NORMAL mode. When this mode is first activated, all active sensors from all connections
	// are disabled. Calling flush() will return an error. In this mode, only the requests from
	// selected apps whose package names are whitelisted are allowed (typically CTS apps). Only
	// these apps can register/unregister/call flush() on sensors. If SensorService switches to
	// NORMAL mode again, all sensors that were previously registered to are activated with the
	// corresponding paramaters if the application hasn't unregistered for sensors in the mean
	// time. NOTE: Non whitelisted app whose sensors were previously deactivated may still
	// receive events if a whitelisted app requests data from the same sensor.
	RESTRICTED = 2

	// State Transitions supported.
	// RESTRICTED <--- NORMAL ---> DATA_INJECTION
	// ---> <---

	// Shell commands to switch modes in SensorService.
	// 1) Put SensorService in RESTRICTED mode with packageName .cts. If it is already in
	// restricted mode it is treated as a NO_OP (and packageName is NOT changed).
	//
	// $ adb shell dumpsys sensorservice restrict .cts.
	//
	// 2) Put SensorService in DATA_INJECTION mode with packageName .xts. If it is already in
	// data_injection mode it is treated as a NO_OP (and packageName is NOT changed).
	//
	// $ adb shell dumpsys sensorservice data_injection .xts.
	//
	// 3) Reset sensorservice back to NORMAL mode.
	// $ adb shell dumpsys sensorservice enable
	};

	static const char* WAKE_LOCK_NAME;
	static char const* getServiceName() ANDROID_API { return "sensorservice"; }
	SensorService() ANDROID_API;
	virtual ~SensorService();

	virtual void onFirstRef();

	// Thread interface
	virtual bool threadLoop();

	// ISensorServer interface
	virtual Vector<Sensor> getSensorList(const String16& opPackageName);
	virtual Vector<Sensor> getDynamicSensorList(const String16& opPackageName);
	virtual sp<ISensorEventConnection> createSensorEventConnection(
	const String8& packageName,
	int requestedMode, const String16& opPackageName);
	virtual int isDataInjectionEnabled();
	virtual sp<ISensorEventConnection> createSensorDirectConnection(const String16& opPackageName,
	uint32_t size, int32_t type, int32_t format, const native_handle *resource);
	virtual int setOperationParameter(
	int32_t handle, int32_t type, const Vector<float> &floats, const Vector<int32_t> &ints);
	virtual status_t dump(int fd, const Vector<String16>& args);
	status_t dumpProtoLocked(int fd, ConnectionSafeAutolock* connLock) const;
	String8 getSensorName(int handle) const;
	bool isVirtualSensor(int handle) const;
	sp<SensorInterface> getSensorInterfaceFromHandle(int handle) const;
	bool isWakeUpSensor(int type) const;
	void recordLastValueLocked(sensors_event_t const* buffer, size_t count);
	static void sortEventBuffer(sensors_event_t* buffer, size_t count);
	const Sensor& registerSensor(SensorInterface* sensor,
	bool isDebug = false, bool isVirtual = false);
	const Sensor& registerVirtualSensor(SensorInterface* sensor, bool isDebug = false);
	const Sensor& registerDynamicSensorLocked(SensorInterface* sensor, bool isDebug = false);
	bool unregisterDynamicSensorLocked(int handle);
	status_t cleanupWithoutDisable(const sp<SensorEventConnection>& connection, int handle);
	status_t cleanupWithoutDisableLocked(const sp<SensorEventConnection>& connection, int handle);
	void cleanupAutoDisabledSensorLocked(const sp<SensorEventConnection>& connection,
	sensors_event_t const* buffer, const int count);
	static bool canAccessSensor(const Sensor& sensor, const char* operation,
	const String16& opPackageName);
	static bool hasPermissionForSensor(const Sensor& sensor);
	static int getTargetSdkVersion(const String16& opPackageName);
	// SensorService acquires a partial wakelock for delivering events from wake up sensors. This
	// method checks whether all the events from these wake up sensors have been delivered to the
	// corresponding applications, if yes the wakelock is released.
	void checkWakeLockState();
	void checkWakeLockStateLocked(ConnectionSafeAutolock* connLock);
	bool isWakeLockAcquired();
	bool isWakeUpSensorEvent(const sensors_event_t& event) const;

	sp<Looper> getLooper() const;

	// Reset mWakeLockRefCounts for all SensorEventConnections to zero. This may happen if
	// SensorService did not receive any acknowledgements from apps which have registered for
	// wake_up sensors.
	void resetAllWakeLockRefCounts();

	// Acquire or release wake_lock. If wake_lock is acquired, set the timeout in the looper to 5
	// seconds and wake the looper.
	void setWakeLockAcquiredLocked(bool acquire);

	// Send events from the event cache for this particular connection.
	void sendEventsFromCache(const sp<SensorEventConnection>& connection);

	// If SensorService is operating in RESTRICTED mode, only select whitelisted packages are
	// allowed to register for or call flush on sensors. Typically only cts test packages are
	// allowed.
	bool isWhiteListedPackage(const String8& packageName);

	// Returns true if a connection with the specified opPackageName has no access to sensors
	// in the RESTRICTED mode (i.e. the service is in RESTRICTED mode, and the package is not
	// whitelisted). mLock must be held to invoke this method.
	bool isOperationRestrictedLocked(const String16& opPackageName);

	// Reset the state of SensorService to NORMAL mode.
	status_t resetToNormalMode();
	status_t resetToNormalModeLocked();

	// Transforms the UUIDs for all the sensors into proper IDs.
	void makeUuidsIntoIdsForSensorList(Vector<Sensor> &sensorList) const;
	// Gets the appropriate ID from the given UUID.
	int32_t getIdFromUuid(const Sensor::uuid_t &uuid) const;
	// Either read from storage or create a new one.
	static bool initializeHmacKey();

	// Enable SCHED_FIFO priority for thread
	void enableSchedFifoMode();

	// Sets whether the given UID can get sensor data
	void onUidStateChanged(uid_t uid, UidState state);

	// Returns true if a connection with the given uid and opPackageName
	// currently has access to sensors.
	bool hasSensorAccess(uid_t uid, const String16& opPackageName);
	// Same as hasSensorAccess but with mLock held.
	bool hasSensorAccessLocked(uid_t uid, const String16& opPackageName);

	// Overrides the UID state as if it is idle
	status_t handleSetUidState(Vector<String16>& args, int err);
	// Clears the override for the UID state
	status_t handleResetUidState(Vector<String16>& args, int err);
	// Gets the UID state
	status_t handleGetUidState(Vector<String16>& args, int out, int err);
	// Prints the shell command help
	status_t printHelp(int out);

	// temporarily stops all active direct connections and disables all sensors
	void disableAllSensors();
	void disableAllSensorsLocked(ConnectionSafeAutolock* connLock);
	// restarts the previously stopped direct connections and enables all sensors
	void enableAllSensors();
	void enableAllSensorsLocked(ConnectionSafeAutolock* connLock);

	static uint8_t sHmacGlobalKey[128];
	static bool sHmacGlobalKeyIsValid;

	SensorServiceUtil::SensorList mSensors;
	status_t mInitCheck;

	// Socket buffersize used to initialize BitTube. This size depends on whether batching is
	// supported or not.
	uint32_t mSocketBufferSize;
	sp<Looper> mLooper;
	sp<SensorEventAckReceiver> mAckReceiver;

	// protected by mLock
	mutable Mutex mLock;
	DefaultKeyedVector<int, SensorRecord*> mActiveSensors;
	std::unordered_set<int> mActiveVirtualSensors;
	SensorConnectionHolder mConnectionHolder;
	bool mWakeLockAcquired;
	sensors_event_t mSensorEventBuffer, mSensorEventScratch;
	// WARNING: these SensorEventConnection instances must not be promoted to sp, except via
	// modification to add support for them in ConnectionSafeAutolock
	wp<const SensorEventConnection> * mMapFlushEventsToConnections;
	std::unordered_map<int, SensorServiceUtil::RecentEventLogger*> mRecentEvent;
	Mode mCurrentOperatingMode;

	// This packagaName is set when SensorService is in RESTRICTED or DATA_INJECTION mode. Only
	// applications with this packageName are allowed to activate/deactivate or call flush on
	// sensors. To run CTS this is can be set to ".cts." and only CTS tests will get access to
	// sensors.
	String8 mWhiteListedPackage;

	int mNextSensorRegIndex;
	Vector<SensorRegistrationInfo> mLastNSensorRegistrations;

	sp<UidPolicy> mUidPolicy;
	sp<SensorPrivacyPolicy> mSensorPrivacyPolicy;

	static AppOpsManager sAppOpsManager;
	static std::map<String16, int> sPackageTargetVersion;
	static Mutex sPackageTargetVersionLock;
	static String16 sSensorInterfaceDescriptorPrefix;
	};

	} // namespace android
	#endif // ANDROID_SENSOR_SERVICE_H