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* 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
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
#include <stdint.h>
#include <sys/types.h>
#include <utils/Vector.h>
#include <utils/SortedVector.h>
#include <utils/KeyedVector.h>
#include <utils/threads.h>
#include <utils/AndroidThreads.h>
#include <utils/RefBase.h>
#include <utils/Looper.h>
#include <binder/BinderService.h>
#include <gui/Sensor.h>
#include <gui/BitTube.h>
#include <gui/ISensorServer.h>
#include <gui/ISensorEventConnection.h>
#include "SensorInterface.h"
// ---------------------------------------------------------------------------
// Max size is 100 KB which is enough to accept a batch of about 1000 events.
// For older HALs which don't support batching, use a smaller socket buffer size.
struct sensors_poll_device_t;
struct sensors_module_t;
namespace android {
// ---------------------------------------------------------------------------
class SensorService :
public BinderService<SensorService>,
public BnSensorServer,
protected Thread
friend class BinderService<SensorService>;
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();
virtual sp<ISensorEventConnection> createSensorEventConnection();
virtual status_t dump(int fd, const Vector<String16>& args);
class SensorEventConnection : public BnSensorEventConnection, public LooperCallback {
friend class SensorService;
virtual ~SensorEventConnection();
virtual void onFirstRef();
virtual sp<BitTube> getSensorChannel() const;
virtual status_t enableDisable(int handle, bool enabled, nsecs_t samplingPeriodNs,
nsecs_t maxBatchReportLatencyNs, int reservedFlags);
virtual status_t setEventRate(int handle, nsecs_t samplingPeriodNs);
virtual status_t flush();
// Count the number of flush complete events which are about to be dropped in the buffer.
// Increment mPendingFlushEventsToSend in mSensorInfo. These flush complete events will be
// sent separately before the next batch of events.
void countFlushCompleteEventsLocked(sensors_event_t const* scratch, int numEventsDropped);
// Check if there are any wake up events in the buffer. If yes, return the index of the
// first wake_up sensor event in the buffer else return -1. This wake_up sensor event will
// have the flag WAKE_UP_SENSOR_EVENT_NEEDS_ACK set. Exactly one event per packet will have
// the wake_up flag set. SOCK_SEQPACKET ensures that either the entire packet is read or
// dropped.
int findWakeUpSensorEventLocked(sensors_event_t const* scratch, int count);
// Send pending flush_complete events. There may have been flush_complete_events that are
// dropped which need to be sent separately before other events. On older HALs (1_0) this
// method emulates the behavior of flush().
void sendPendingFlushEventsLocked();
// Writes events from mEventCache to the socket.
void writeToSocketFromCache();
// Compute the approximate cache size from the FIFO sizes of various sensors registered for
// this connection. Wake up and non-wake up sensors have separate FIFOs but FIFO may be
// shared amongst wake-up sensors and non-wake up sensors.
int computeMaxCacheSizeLocked() const;
// When more sensors register, the maximum cache size desired may change. Compute max cache
// size, reallocate memory and copy over events from the older cache.
void reAllocateCacheLocked(sensors_event_t const* scratch, int count);
// LooperCallback method. If there is data to read on this fd, it is an ack from the
// app that it has read events from a wake up sensor, decrement mWakeLockRefCount.
// If this fd is available for writing send the data from the cache.
virtual int handleEvent(int fd, int events, void* data);
// Increment mPendingFlushEventsToSend for the given sensor handle.
void incrementPendingFlushCount(int32_t handle);
// Add or remove the file descriptor associated with the BitTube to the looper. If mDead is
// set to true or there are no more sensors for this connection, the file descriptor is
// removed if it has been previously added to the Looper. Depending on the state of the
// connection FD may be added to the Looper. The flags to set are determined by the internal
// state of the connection. FDs are added to the looper when wake-up sensors are registered
// (to poll for acknowledgements) and when write fails on the socket when there are too many
// events (to poll when the FD is available for writing). FDs are removed when there is an
// error and the other end hangs up or when this client unregisters for this connection.
void updateLooperRegistration(const sp<Looper>& looper);
void updateLooperRegistrationLocked(const sp<Looper>& looper);
sp<SensorService> const mService;
sp<BitTube> mChannel;
uid_t mUid;
mutable Mutex mConnectionLock;
// Number of events from wake up sensors which are still pending and haven't been delivered
// to the corresponding application. It is incremented by one unit for each write to the
// socket.
uint32_t mWakeLockRefCount;
// If this flag is set to true, it means that the file descriptor associated with the
// BitTube has been added to the Looper in SensorService. This flag is typically set when
// this connection has wake-up sensors associated with it or when write has failed on this
// connection and we're storing some events in the cache.
bool mHasLooperCallbacks;
// If there are any errors associated with the Looper this flag is set to true and
// mWakeLockRefCount is reset to zero. needsWakeLock method will always return false, if
// this flag is set.
bool mDead;
struct FlushInfo {
// The number of flush complete events dropped for this sensor is stored here.
// They are sent separately before the next batch of events.
int mPendingFlushEventsToSend;
// Every activate is preceded by a flush. Only after the first flush complete is
// received, the events for the sensor are sent on that *connection*.
bool mFirstFlushPending;
FlushInfo() : mPendingFlushEventsToSend(0), mFirstFlushPending(false) {}
// protected by SensorService::mLock. Key for this vector is the sensor handle.
KeyedVector<int, FlushInfo> mSensorInfo;
sensors_event_t *mEventCache;
int mCacheSize, mMaxCacheSize;
int mEventsReceived, mEventsSent, mEventsSentFromCache;
int mTotalAcksNeeded, mTotalAcksReceived;
SensorEventConnection(const sp<SensorService>& service, uid_t uid);
status_t sendEvents(sensors_event_t const* buffer, size_t count,
sensors_event_t* scratch,
SensorEventConnection const * const * mapFlushEventsToConnections = NULL);
bool hasSensor(int32_t handle) const;
bool hasAnySensor() const;
bool hasOneShotSensors() const;
bool addSensor(int32_t handle);
bool removeSensor(int32_t handle);
void setFirstFlushPending(int32_t handle, bool value);
void dump(String8& result);
bool needsWakeLock();
void resetWakeLockRefCount();
uid_t getUid() const { return mUid; }
class SensorRecord {
SortedVector< wp<SensorEventConnection> > mConnections;
// A queue of all flush() calls made on this sensor. Flush complete events will be
// sent in this order.
Vector< wp<SensorEventConnection> > mPendingFlushConnections;
SensorRecord(const sp<SensorEventConnection>& connection);
bool addConnection(const sp<SensorEventConnection>& connection);
bool removeConnection(const wp<SensorEventConnection>& connection);
size_t getNumConnections() const { return mConnections.size(); }
void addPendingFlushConnection(const sp<SensorEventConnection>& connection);
void removeFirstPendingFlushConnection();
SensorEventConnection * getFirstPendingFlushConnection();
class SensorEventAckReceiver : public Thread {
sp<SensorService> const mService;
virtual bool threadLoop();
SensorEventAckReceiver(const sp<SensorService>& service): mService(service) {}
String8 getSensorName(int handle) const;
bool isVirtualSensor(int handle) const;
Sensor getSensorFromHandle(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);
Sensor registerSensor(SensorInterface* sensor);
Sensor registerVirtualSensor(SensorInterface* sensor);
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);
static bool verifyCanAccessSensor(const Sensor& sensor, const char* operation);
// 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();
bool isWakeLockAcquired();
bool isWakeUpSensorEvent(const sensors_event_t& event) const;
SensorRecord * getSensorRecord(int handle);
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);
// Promote all weak referecences in mActiveConnections vector to strong references and add them
// to the output vector.
void populateActiveConnections(SortedVector< sp<SensorEventConnection> >* activeConnections);
// constants
Vector<Sensor> mSensorList;
Vector<Sensor> mUserSensorListDebug;
Vector<Sensor> mUserSensorList;
DefaultKeyedVector<int, SensorInterface*> mSensorMap;
Vector<SensorInterface *> mVirtualSensorList;
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;
DefaultKeyedVector<int, SensorInterface*> mActiveVirtualSensors;
SortedVector< wp<SensorEventConnection> > mActiveConnections;
bool mWakeLockAcquired;
sensors_event_t *mSensorEventBuffer, *mSensorEventScratch;
SensorEventConnection const **mMapFlushEventsToConnections;
// The size of this vector is constant, only the items are mutable
KeyedVector<int32_t, sensors_event_t> mLastEventSeen;
void cleanupConnection(SensorEventConnection* connection);
status_t enable(const sp<SensorEventConnection>& connection, int handle,
nsecs_t samplingPeriodNs, nsecs_t maxBatchReportLatencyNs, int reservedFlags);
status_t disable(const sp<SensorEventConnection>& connection, int handle);
status_t setEventRate(const sp<SensorEventConnection>& connection, int handle, nsecs_t ns);
status_t flushSensor(const sp<SensorEventConnection>& connection);
// ---------------------------------------------------------------------------
}; // namespace android