core/java/android/hardware/SystemSensorManager.java - platform/frameworks/base - Git at Google

     /*
  * Copyright (C) 2012 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.
  */

 package android.hardware;

 import android.content.Context;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.MessageQueue;
 import android.util.Log;
 import android.util.SparseArray;
 import android.util.SparseBooleanArray;
 import android.util.SparseIntArray;
 import dalvik.system.CloseGuard;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;

 /**
  * Sensor manager implementation that communicates with the built-in
  * system sensors.
  *
  * @hide
  */
 public class SystemSensorManager extends SensorManager {
     private static native void nativeClassInit();
     private static native int nativeGetNextSensor(Sensor sensor, int next);

     private static boolean sSensorModuleInitialized = false;
     private static final Object sSensorModuleLock = new Object();
     private static final ArrayList<Sensor> sFullSensorsList = new ArrayList<Sensor>();
     private static final SparseArray<Sensor> sHandleToSensor = new SparseArray<Sensor>();

     // Listener list
     private final HashMap<SensorEventListener, SensorEventQueue> mSensorListeners =
             new HashMap<SensorEventListener, SensorEventQueue>();
     private final HashMap<TriggerEventListener, TriggerEventQueue> mTriggerListeners =
             new HashMap<TriggerEventListener, TriggerEventQueue>();

     // Looper associated with the context in which this instance was created.
     private final Looper mMainLooper;
     private final int mTargetSdkLevel;

     /** {@hide} */
     public SystemSensorManager(Context context, Looper mainLooper) {
         mMainLooper = mainLooper;
         mTargetSdkLevel = context.getApplicationInfo().targetSdkVersion;
         synchronized(sSensorModuleLock) {
             if (!sSensorModuleInitialized) {
                 sSensorModuleInitialized = true;

                 nativeClassInit();

                 // initialize the sensor list
                 final ArrayList<Sensor> fullList = sFullSensorsList;
                 int i = 0;
                 do {
                     Sensor sensor = new Sensor();
                     i = nativeGetNextSensor(sensor, i);
                     if (i>=0) {
                         //Log.d(TAG, "found sensor: " + sensor.getName() +
                         //        ", handle=" + sensor.getHandle());
                         fullList.add(sensor);
                         sHandleToSensor.append(sensor.getHandle(), sensor);
                     }
                 } while (i>0);
             }
         }
     }


     /** @hide */
     @Override
     protected List<Sensor> getFullSensorList() {
         return sFullSensorsList;
     }


     /** @hide */
     @Override
     protected boolean registerListenerImpl(SensorEventListener listener, Sensor sensor,
             int delayUs, Handler handler, int maxBatchReportLatencyUs, int reservedFlags) {
         if (listener == null || sensor == null) {
             Log.e(TAG, "sensor or listener is null");
             return false;
         }
         // Trigger Sensors should use the requestTriggerSensor call.
         if (sensor.getReportingMode() == Sensor.REPORTING_MODE_ONE_SHOT) {
             Log.e(TAG, "Trigger Sensors should use the requestTriggerSensor.");
             return false;
         }
         if (maxBatchReportLatencyUs < 0 || delayUs < 0) {
             Log.e(TAG, "maxBatchReportLatencyUs and delayUs should be non-negative");
             return false;
         }

         // Invariants to preserve:
         // - one Looper per SensorEventListener
         // - one Looper per SensorEventQueue
         // We map SensorEventListener to a SensorEventQueue, which holds the looper
         synchronized (mSensorListeners) {
             SensorEventQueue queue = mSensorListeners.get(listener);
             if (queue == null) {
                 Looper looper = (handler != null) ? handler.getLooper() : mMainLooper;
                 queue = new SensorEventQueue(listener, looper, this);
                 if (!queue.addSensor(sensor, delayUs, maxBatchReportLatencyUs, reservedFlags)) {
                     queue.dispose();
                     return false;
                 }
                 mSensorListeners.put(listener, queue);
                 return true;
             } else {
                 return queue.addSensor(sensor, delayUs, maxBatchReportLatencyUs, reservedFlags);
             }
         }
     }

     /** @hide */
     @Override
     protected void unregisterListenerImpl(SensorEventListener listener, Sensor sensor) {
         // Trigger Sensors should use the cancelTriggerSensor call.
         if (sensor != null && sensor.getReportingMode() == Sensor.REPORTING_MODE_ONE_SHOT) {
             return;
         }

         synchronized (mSensorListeners) {
             SensorEventQueue queue = mSensorListeners.get(listener);
             if (queue != null) {
                 boolean result;
                 if (sensor == null) {
                     result = queue.removeAllSensors();
                 } else {
                     result = queue.removeSensor(sensor, true);
                 }
                 if (result && !queue.hasSensors()) {
                     mSensorListeners.remove(listener);
                     queue.dispose();
                 }
             }
         }
     }

     /** @hide */
     @Override
     protected boolean requestTriggerSensorImpl(TriggerEventListener listener, Sensor sensor) {
         if (sensor == null) throw new IllegalArgumentException("sensor cannot be null");

         if (sensor.getReportingMode() != Sensor.REPORTING_MODE_ONE_SHOT) return false;

         synchronized (mTriggerListeners) {
             TriggerEventQueue queue = mTriggerListeners.get(listener);
             if (queue == null) {
                 queue = new TriggerEventQueue(listener, mMainLooper, this);
                 if (!queue.addSensor(sensor, 0, 0, 0)) {
                     queue.dispose();
                     return false;
                 }
                 mTriggerListeners.put(listener, queue);
                 return true;
             } else {
                 return queue.addSensor(sensor, 0, 0, 0);
             }
         }
     }

     /** @hide */
     @Override
     protected boolean cancelTriggerSensorImpl(TriggerEventListener listener, Sensor sensor,
             boolean disable) {
         if (sensor != null && sensor.getReportingMode() != Sensor.REPORTING_MODE_ONE_SHOT) {
             return false;
         }
         synchronized (mTriggerListeners) {
             TriggerEventQueue queue = mTriggerListeners.get(listener);
             if (queue != null) {
                 boolean result;
                 if (sensor == null) {
                     result = queue.removeAllSensors();
                 } else {
                     result = queue.removeSensor(sensor, disable);
                 }
                 if (result && !queue.hasSensors()) {
                     mTriggerListeners.remove(listener);
                     queue.dispose();
                 }
                 return result;
             }
             return false;
         }
     }

     protected boolean flushImpl(SensorEventListener listener) {
         if (listener == null) throw new IllegalArgumentException("listener cannot be null");

         synchronized (mSensorListeners) {
             SensorEventQueue queue = mSensorListeners.get(listener);
             if (queue == null) {
                 return false;
             } else {
                 return (queue.flush() == 0);
             }
         }
     }

     /*
      * BaseEventQueue is the communication channel with the sensor service,
      * SensorEventQueue, TriggerEventQueue are subclases and there is one-to-one mapping between
      * the queues and the listeners.
      */
     private static abstract class BaseEventQueue {
         private native long nativeInitBaseEventQueue(BaseEventQueue eventQ, MessageQueue msgQ,
                 float[] scratch);
         private static native int nativeEnableSensor(long eventQ, int handle, int rateUs,
                 int maxBatchReportLatencyUs, int reservedFlags);
         private static native int nativeDisableSensor(long eventQ, int handle);
         private static native void nativeDestroySensorEventQueue(long eventQ);
         private static native int nativeFlushSensor(long eventQ);
         private long nSensorEventQueue;
         private final SparseBooleanArray mActiveSensors = new SparseBooleanArray();
         protected final SparseIntArray mSensorAccuracies = new SparseIntArray();
         protected final SparseBooleanArray mFirstEvent = new SparseBooleanArray();
         private final CloseGuard mCloseGuard = CloseGuard.get();
         private final float[] mScratch = new float[16];
         protected final SystemSensorManager mManager;

         BaseEventQueue(Looper looper, SystemSensorManager manager) {
             nSensorEventQueue = nativeInitBaseEventQueue(this, looper.getQueue(), mScratch);
             mCloseGuard.open("dispose");
             mManager = manager;
         }

         public void dispose() {
             dispose(false);
         }

         public boolean addSensor(
                 Sensor sensor, int delayUs, int maxBatchReportLatencyUs, int reservedFlags) {
             // Check if already present.
             int handle = sensor.getHandle();
             if (mActiveSensors.get(handle)) return false;

             // Get ready to receive events before calling enable.
             mActiveSensors.put(handle, true);
             addSensorEvent(sensor);
             if (enableSensor(sensor, delayUs, maxBatchReportLatencyUs, reservedFlags) != 0) {
                 // Try continuous mode if batching fails.
                 if (maxBatchReportLatencyUs == 0 ||
                     maxBatchReportLatencyUs > 0 && enableSensor(sensor, delayUs, 0, 0) != 0) {
                   removeSensor(sensor, false);
                   return false;
                 }
             }
             return true;
         }

         public boolean removeAllSensors() {
             for (int i=0 ; i<mActiveSensors.size(); i++) {
                 if (mActiveSensors.valueAt(i) == true) {
                     int handle = mActiveSensors.keyAt(i);
                     Sensor sensor = sHandleToSensor.get(handle);
                     if (sensor != null) {
                         disableSensor(sensor);
                         mActiveSensors.put(handle, false);
                         removeSensorEvent(sensor);
                     } else {
                         // it should never happen -- just ignore.
                     }
                 }
             }
             return true;
         }

         public boolean removeSensor(Sensor sensor, boolean disable) {
             final int handle = sensor.getHandle();
             if (mActiveSensors.get(handle)) {
                 if (disable) disableSensor(sensor);
                 mActiveSensors.put(sensor.getHandle(), false);
                 removeSensorEvent(sensor);
                 return true;
             }
             return false;
         }

         public int flush() {
             if (nSensorEventQueue == 0) throw new NullPointerException();
             return nativeFlushSensor(nSensorEventQueue);
         }

         public boolean hasSensors() {
             // no more sensors are set
             return mActiveSensors.indexOfValue(true) >= 0;
         }

         @Override
         protected void finalize() throws Throwable {
             try {
                 dispose(true);
             } finally {
                 super.finalize();
             }
         }

         private void dispose(boolean finalized) {
             if (mCloseGuard != null) {
                 if (finalized) {
                     mCloseGuard.warnIfOpen();
                 }
                 mCloseGuard.close();
             }
             if (nSensorEventQueue != 0) {
                 nativeDestroySensorEventQueue(nSensorEventQueue);
                 nSensorEventQueue = 0;
             }
         }

         private int enableSensor(
                 Sensor sensor, int rateUs, int maxBatchReportLatencyUs, int reservedFlags) {
             if (nSensorEventQueue == 0) throw new NullPointerException();
             if (sensor == null) throw new NullPointerException();
             return nativeEnableSensor(nSensorEventQueue, sensor.getHandle(), rateUs,
                     maxBatchReportLatencyUs, reservedFlags);
         }

         private int disableSensor(Sensor sensor) {
             if (nSensorEventQueue == 0) throw new NullPointerException();
             if (sensor == null) throw new NullPointerException();
             return nativeDisableSensor(nSensorEventQueue, sensor.getHandle());
         }
         protected abstract void dispatchSensorEvent(int handle, float[] values, int accuracy,
                 long timestamp);
         protected abstract void dispatchFlushCompleteEvent(int handle);

         protected abstract void addSensorEvent(Sensor sensor);
         protected abstract void removeSensorEvent(Sensor sensor);
     }

     static final class SensorEventQueue extends BaseEventQueue {
         private final SensorEventListener mListener;
         private final SparseArray<SensorEvent> mSensorsEvents = new SparseArray<SensorEvent>();

         public SensorEventQueue(SensorEventListener listener, Looper looper,
                 SystemSensorManager manager) {
             super(looper, manager);
             mListener = listener;
         }

         @Override
         public void addSensorEvent(Sensor sensor) {
             SensorEvent t = new SensorEvent(Sensor.getMaxLengthValuesArray(sensor,
                     mManager.mTargetSdkLevel));
             synchronized (mSensorsEvents) {
                 mSensorsEvents.put(sensor.getHandle(), t);
             }
         }

         @Override
         public void removeSensorEvent(Sensor sensor) {
             synchronized (mSensorsEvents) {
                 mSensorsEvents.delete(sensor.getHandle());
             }
         }

         // Called from native code.
         @SuppressWarnings("unused")
         @Override
         protected void dispatchSensorEvent(int handle, float[] values, int inAccuracy,
                 long timestamp) {
             final Sensor sensor = sHandleToSensor.get(handle);
             SensorEvent t = null;
             synchronized (mSensorsEvents) {
                 t = mSensorsEvents.get(handle);
             }

             if (t == null) {
                 // This may happen if the client has unregistered and there are pending events in
                 // the queue waiting to be delivered. Ignore.
                 return;
             }
             // Copy from the values array.
             System.arraycopy(values, 0, t.values, 0, t.values.length);
             t.timestamp = timestamp;
             t.accuracy = inAccuracy;
             t.sensor = sensor;

             // call onAccuracyChanged() only if the value changes
             final int accuracy = mSensorAccuracies.get(handle);
             if ((t.accuracy >= 0) && (accuracy != t.accuracy)) {
                 mSensorAccuracies.put(handle, t.accuracy);
                 mListener.onAccuracyChanged(t.sensor, t.accuracy);
             }
             mListener.onSensorChanged(t);
         }

         @SuppressWarnings("unused")
         protected void dispatchFlushCompleteEvent(int handle) {
             if (mListener instanceof SensorEventListener2) {
                 final Sensor sensor = sHandleToSensor.get(handle);
                 ((SensorEventListener2)mListener).onFlushCompleted(sensor);
             }
             return;
         }
     }

     static final class TriggerEventQueue extends BaseEventQueue {
         private final TriggerEventListener mListener;
         private final SparseArray<TriggerEvent> mTriggerEvents = new SparseArray<TriggerEvent>();

         public TriggerEventQueue(TriggerEventListener listener, Looper looper,
                 SystemSensorManager manager) {
             super(looper, manager);
             mListener = listener;
         }

         @Override
         public void addSensorEvent(Sensor sensor) {
             TriggerEvent t = new TriggerEvent(Sensor.getMaxLengthValuesArray(sensor,
                     mManager.mTargetSdkLevel));
             synchronized (mTriggerEvents) {
                 mTriggerEvents.put(sensor.getHandle(), t);
             }
         }

         @Override
         public void removeSensorEvent(Sensor sensor) {
             synchronized (mTriggerEvents) {
                 mTriggerEvents.delete(sensor.getHandle());
             }
         }

         // Called from native code.
         @SuppressWarnings("unused")
         @Override
         protected void dispatchSensorEvent(int handle, float[] values, int accuracy,
                 long timestamp) {
             final Sensor sensor = sHandleToSensor.get(handle);
             TriggerEvent t = null;
             synchronized (mTriggerEvents) {
                 t = mTriggerEvents.get(handle);
             }
             if (t == null) {
                 Log.e(TAG, "Error: Trigger Event is null for Sensor: " + sensor);
                 return;
             }

             // Copy from the values array.
             System.arraycopy(values, 0, t.values, 0, t.values.length);
             t.timestamp = timestamp;
             t.sensor = sensor;

             // A trigger sensor is auto disabled. So just clean up and don't call native
             // disable.
             mManager.cancelTriggerSensorImpl(mListener, sensor, false);

             mListener.onTrigger(t);
         }

         @SuppressWarnings("unused")
         protected void dispatchFlushCompleteEvent(int handle) {
         }
     }
 }
	/*
	* Copyright (C) 2012 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.
	*/

	package android.hardware;

	import android.content.Context;
	import android.os.Handler;
	import android.os.Looper;
	import android.os.MessageQueue;
	import android.util.Log;
	import android.util.SparseArray;
	import android.util.SparseBooleanArray;
	import android.util.SparseIntArray;
	import dalvik.system.CloseGuard;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.List;

	/**
	* Sensor manager implementation that communicates with the built-in
	* system sensors.
	*
	* @hide
	*/
	public class SystemSensorManager extends SensorManager {
	private static native void nativeClassInit();
	private static native int nativeGetNextSensor(Sensor sensor, int next);

	private static boolean sSensorModuleInitialized = false;
	private static final Object sSensorModuleLock = new Object();
	private static final ArrayList<Sensor> sFullSensorsList = new ArrayList<Sensor>();
	private static final SparseArray<Sensor> sHandleToSensor = new SparseArray<Sensor>();

	// Listener list
	private final HashMap<SensorEventListener, SensorEventQueue> mSensorListeners =
	new HashMap<SensorEventListener, SensorEventQueue>();
	private final HashMap<TriggerEventListener, TriggerEventQueue> mTriggerListeners =
	new HashMap<TriggerEventListener, TriggerEventQueue>();

	// Looper associated with the context in which this instance was created.
	private final Looper mMainLooper;
	private final int mTargetSdkLevel;

	/** {@hide} */
	public SystemSensorManager(Context context, Looper mainLooper) {
	mMainLooper = mainLooper;
	mTargetSdkLevel = context.getApplicationInfo().targetSdkVersion;
	synchronized(sSensorModuleLock) {
	if (!sSensorModuleInitialized) {
	sSensorModuleInitialized = true;

	nativeClassInit();

	// initialize the sensor list
	final ArrayList<Sensor> fullList = sFullSensorsList;
	int i = 0;
	do {
	Sensor sensor = new Sensor();
	i = nativeGetNextSensor(sensor, i);
	if (i>=0) {
	//Log.d(TAG, "found sensor: " + sensor.getName() +
	// ", handle=" + sensor.getHandle());
	fullList.add(sensor);
	sHandleToSensor.append(sensor.getHandle(), sensor);
	}
	} while (i>0);
	}
	}
	}


	/** @hide */
	@Override
	protected List<Sensor> getFullSensorList() {
	return sFullSensorsList;
	}


	/** @hide */
	@Override
	protected boolean registerListenerImpl(SensorEventListener listener, Sensor sensor,
	int delayUs, Handler handler, int maxBatchReportLatencyUs, int reservedFlags) {
	if (listener == null \|\| sensor == null) {
	Log.e(TAG, "sensor or listener is null");
	return false;
	}
	// Trigger Sensors should use the requestTriggerSensor call.
	if (sensor.getReportingMode() == Sensor.REPORTING_MODE_ONE_SHOT) {
	Log.e(TAG, "Trigger Sensors should use the requestTriggerSensor.");
	return false;
	}
	if (maxBatchReportLatencyUs < 0 \|\| delayUs < 0) {
	Log.e(TAG, "maxBatchReportLatencyUs and delayUs should be non-negative");
	return false;
	}

	// Invariants to preserve:
	// - one Looper per SensorEventListener
	// - one Looper per SensorEventQueue
	// We map SensorEventListener to a SensorEventQueue, which holds the looper
	synchronized (mSensorListeners) {
	SensorEventQueue queue = mSensorListeners.get(listener);
	if (queue == null) {
	Looper looper = (handler != null) ? handler.getLooper() : mMainLooper;
	queue = new SensorEventQueue(listener, looper, this);
	if (!queue.addSensor(sensor, delayUs, maxBatchReportLatencyUs, reservedFlags)) {
	queue.dispose();
	return false;
	}
	mSensorListeners.put(listener, queue);
	return true;
	} else {
	return queue.addSensor(sensor, delayUs, maxBatchReportLatencyUs, reservedFlags);
	}
	}
	}

	/** @hide */
	@Override
	protected void unregisterListenerImpl(SensorEventListener listener, Sensor sensor) {
	// Trigger Sensors should use the cancelTriggerSensor call.
	if (sensor != null && sensor.getReportingMode() == Sensor.REPORTING_MODE_ONE_SHOT) {
	return;
	}

	synchronized (mSensorListeners) {
	SensorEventQueue queue = mSensorListeners.get(listener);
	if (queue != null) {
	boolean result;
	if (sensor == null) {
	result = queue.removeAllSensors();
	} else {
	result = queue.removeSensor(sensor, true);
	}
	if (result && !queue.hasSensors()) {
	mSensorListeners.remove(listener);
	queue.dispose();
	}
	}
	}
	}

	/** @hide */
	@Override
	protected boolean requestTriggerSensorImpl(TriggerEventListener listener, Sensor sensor) {
	if (sensor == null) throw new IllegalArgumentException("sensor cannot be null");

	if (sensor.getReportingMode() != Sensor.REPORTING_MODE_ONE_SHOT) return false;

	synchronized (mTriggerListeners) {
	TriggerEventQueue queue = mTriggerListeners.get(listener);
	if (queue == null) {
	queue = new TriggerEventQueue(listener, mMainLooper, this);
	if (!queue.addSensor(sensor, 0, 0, 0)) {
	queue.dispose();
	return false;
	}
	mTriggerListeners.put(listener, queue);
	return true;
	} else {
	return queue.addSensor(sensor, 0, 0, 0);
	}
	}
	}

	/** @hide */
	@Override
	protected boolean cancelTriggerSensorImpl(TriggerEventListener listener, Sensor sensor,
	boolean disable) {
	if (sensor != null && sensor.getReportingMode() != Sensor.REPORTING_MODE_ONE_SHOT) {
	return false;
	}
	synchronized (mTriggerListeners) {
	TriggerEventQueue queue = mTriggerListeners.get(listener);
	if (queue != null) {
	boolean result;
	if (sensor == null) {
	result = queue.removeAllSensors();
	} else {
	result = queue.removeSensor(sensor, disable);
	}
	if (result && !queue.hasSensors()) {
	mTriggerListeners.remove(listener);
	queue.dispose();
	}
	return result;
	}
	return false;
	}
	}

	protected boolean flushImpl(SensorEventListener listener) {
	if (listener == null) throw new IllegalArgumentException("listener cannot be null");

	synchronized (mSensorListeners) {
	SensorEventQueue queue = mSensorListeners.get(listener);
	if (queue == null) {
	return false;
	} else {
	return (queue.flush() == 0);
	}
	}
	}

	/*
	* BaseEventQueue is the communication channel with the sensor service,
	* SensorEventQueue, TriggerEventQueue are subclases and there is one-to-one mapping between
	* the queues and the listeners.
	*/
	private static abstract class BaseEventQueue {
	private native long nativeInitBaseEventQueue(BaseEventQueue eventQ, MessageQueue msgQ,
	float[] scratch);
	private static native int nativeEnableSensor(long eventQ, int handle, int rateUs,
	int maxBatchReportLatencyUs, int reservedFlags);
	private static native int nativeDisableSensor(long eventQ, int handle);
	private static native void nativeDestroySensorEventQueue(long eventQ);
	private static native int nativeFlushSensor(long eventQ);
	private long nSensorEventQueue;
	private final SparseBooleanArray mActiveSensors = new SparseBooleanArray();
	protected final SparseIntArray mSensorAccuracies = new SparseIntArray();
	protected final SparseBooleanArray mFirstEvent = new SparseBooleanArray();
	private final CloseGuard mCloseGuard = CloseGuard.get();
	private final float[] mScratch = new float[16];
	protected final SystemSensorManager mManager;

	BaseEventQueue(Looper looper, SystemSensorManager manager) {
	nSensorEventQueue = nativeInitBaseEventQueue(this, looper.getQueue(), mScratch);
	mCloseGuard.open("dispose");
	mManager = manager;
	}

	public void dispose() {
	dispose(false);
	}

	public boolean addSensor(
	Sensor sensor, int delayUs, int maxBatchReportLatencyUs, int reservedFlags) {
	// Check if already present.
	int handle = sensor.getHandle();
	if (mActiveSensors.get(handle)) return false;

	// Get ready to receive events before calling enable.
	mActiveSensors.put(handle, true);
	addSensorEvent(sensor);
	if (enableSensor(sensor, delayUs, maxBatchReportLatencyUs, reservedFlags) != 0) {
	// Try continuous mode if batching fails.
	if (maxBatchReportLatencyUs == 0 \|\|
	maxBatchReportLatencyUs > 0 && enableSensor(sensor, delayUs, 0, 0) != 0) {
	removeSensor(sensor, false);
	return false;
	}
	}
	return true;
	}

	public boolean removeAllSensors() {
	for (int i=0 ; i<mActiveSensors.size(); i++) {
	if (mActiveSensors.valueAt(i) == true) {
	int handle = mActiveSensors.keyAt(i);
	Sensor sensor = sHandleToSensor.get(handle);
	if (sensor != null) {
	disableSensor(sensor);
	mActiveSensors.put(handle, false);
	removeSensorEvent(sensor);
	} else {
	// it should never happen -- just ignore.
	}
	}
	}
	return true;
	}

	public boolean removeSensor(Sensor sensor, boolean disable) {
	final int handle = sensor.getHandle();
	if (mActiveSensors.get(handle)) {
	if (disable) disableSensor(sensor);
	mActiveSensors.put(sensor.getHandle(), false);
	removeSensorEvent(sensor);
	return true;
	}
	return false;
	}

	public int flush() {
	if (nSensorEventQueue == 0) throw new NullPointerException();
	return nativeFlushSensor(nSensorEventQueue);
	}

	public boolean hasSensors() {
	// no more sensors are set
	return mActiveSensors.indexOfValue(true) >= 0;
	}

	@Override
	protected void finalize() throws Throwable {
	try {
	dispose(true);
	} finally {
	super.finalize();
	}
	}

	private void dispose(boolean finalized) {
	if (mCloseGuard != null) {
	if (finalized) {
	mCloseGuard.warnIfOpen();
	}
	mCloseGuard.close();
	}
	if (nSensorEventQueue != 0) {
	nativeDestroySensorEventQueue(nSensorEventQueue);
	nSensorEventQueue = 0;
	}
	}

	private int enableSensor(
	Sensor sensor, int rateUs, int maxBatchReportLatencyUs, int reservedFlags) {
	if (nSensorEventQueue == 0) throw new NullPointerException();
	if (sensor == null) throw new NullPointerException();
	return nativeEnableSensor(nSensorEventQueue, sensor.getHandle(), rateUs,
	maxBatchReportLatencyUs, reservedFlags);
	}

	private int disableSensor(Sensor sensor) {
	if (nSensorEventQueue == 0) throw new NullPointerException();
	if (sensor == null) throw new NullPointerException();
	return nativeDisableSensor(nSensorEventQueue, sensor.getHandle());
	}
	protected abstract void dispatchSensorEvent(int handle, float[] values, int accuracy,
	long timestamp);
	protected abstract void dispatchFlushCompleteEvent(int handle);

	protected abstract void addSensorEvent(Sensor sensor);
	protected abstract void removeSensorEvent(Sensor sensor);
	}

	static final class SensorEventQueue extends BaseEventQueue {
	private final SensorEventListener mListener;
	private final SparseArray<SensorEvent> mSensorsEvents = new SparseArray<SensorEvent>();

	public SensorEventQueue(SensorEventListener listener, Looper looper,
	SystemSensorManager manager) {
	super(looper, manager);
	mListener = listener;
	}

	@Override
	public void addSensorEvent(Sensor sensor) {
	SensorEvent t = new SensorEvent(Sensor.getMaxLengthValuesArray(sensor,
	mManager.mTargetSdkLevel));
	synchronized (mSensorsEvents) {
	mSensorsEvents.put(sensor.getHandle(), t);
	}
	}

	@Override
	public void removeSensorEvent(Sensor sensor) {
	synchronized (mSensorsEvents) {
	mSensorsEvents.delete(sensor.getHandle());
	}
	}

	// Called from native code.
	@SuppressWarnings("unused")
	@Override
	protected void dispatchSensorEvent(int handle, float[] values, int inAccuracy,
	long timestamp) {
	final Sensor sensor = sHandleToSensor.get(handle);
	SensorEvent t = null;
	synchronized (mSensorsEvents) {
	t = mSensorsEvents.get(handle);
	}

	if (t == null) {
	// This may happen if the client has unregistered and there are pending events in
	// the queue waiting to be delivered. Ignore.
	return;
	}
	// Copy from the values array.
	System.arraycopy(values, 0, t.values, 0, t.values.length);
	t.timestamp = timestamp;
	t.accuracy = inAccuracy;
	t.sensor = sensor;

	// call onAccuracyChanged() only if the value changes
	final int accuracy = mSensorAccuracies.get(handle);
	if ((t.accuracy >= 0) && (accuracy != t.accuracy)) {
	mSensorAccuracies.put(handle, t.accuracy);
	mListener.onAccuracyChanged(t.sensor, t.accuracy);
	}
	mListener.onSensorChanged(t);
	}

	@SuppressWarnings("unused")
	protected void dispatchFlushCompleteEvent(int handle) {
	if (mListener instanceof SensorEventListener2) {
	final Sensor sensor = sHandleToSensor.get(handle);
	((SensorEventListener2)mListener).onFlushCompleted(sensor);
	}
	return;
	}
	}

	static final class TriggerEventQueue extends BaseEventQueue {
	private final TriggerEventListener mListener;
	private final SparseArray<TriggerEvent> mTriggerEvents = new SparseArray<TriggerEvent>();

	public TriggerEventQueue(TriggerEventListener listener, Looper looper,
	SystemSensorManager manager) {
	super(looper, manager);
	mListener = listener;
	}

	@Override
	public void addSensorEvent(Sensor sensor) {
	TriggerEvent t = new TriggerEvent(Sensor.getMaxLengthValuesArray(sensor,
	mManager.mTargetSdkLevel));
	synchronized (mTriggerEvents) {
	mTriggerEvents.put(sensor.getHandle(), t);
	}
	}

	@Override
	public void removeSensorEvent(Sensor sensor) {
	synchronized (mTriggerEvents) {
	mTriggerEvents.delete(sensor.getHandle());
	}
	}

	// Called from native code.
	@SuppressWarnings("unused")
	@Override
	protected void dispatchSensorEvent(int handle, float[] values, int accuracy,
	long timestamp) {
	final Sensor sensor = sHandleToSensor.get(handle);
	TriggerEvent t = null;
	synchronized (mTriggerEvents) {
	t = mTriggerEvents.get(handle);
	}
	if (t == null) {
	Log.e(TAG, "Error: Trigger Event is null for Sensor: " + sensor);
	return;
	}

	// Copy from the values array.
	System.arraycopy(values, 0, t.values, 0, t.values.length);
	t.timestamp = timestamp;
	t.sensor = sensor;

	// A trigger sensor is auto disabled. So just clean up and don't call native
	// disable.
	mManager.cancelTriggerSensorImpl(mListener, sensor, false);

	mListener.onTrigger(t);
	}

	@SuppressWarnings("unused")
	protected void dispatchFlushCompleteEvent(int handle) {
	}
	}
	}