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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_SENSOR_EVENT_QUEUE_H
     18 #define ANDROID_SENSOR_EVENT_QUEUE_H
     19 
     20 #include <stdint.h>
     21 #include <sys/types.h>
     22 
     23 #include <utils/Errors.h>
     24 #include <utils/RefBase.h>
     25 #include <utils/Timers.h>
     26 #include <utils/String16.h>
     27 
     28 #include <gui/BitTube.h>
     29 
     30 // ----------------------------------------------------------------------------
     31 #define WAKE_UP_SENSOR_EVENT_NEEDS_ACK (1U << 31)
     32 struct ALooper;
     33 struct ASensorEvent;
     34 
     35 // Concrete types for the NDK
     36 struct ASensorEventQueue {
     37     ALooper* looper;
     38 };
     39 
     40 // ----------------------------------------------------------------------------
     41 namespace android {
     42 // ----------------------------------------------------------------------------
     43 
     44 class ISensorEventConnection;
     45 class Sensor;
     46 class Looper;
     47 
     48 // ----------------------------------------------------------------------------
     49 
     50 class SensorEventQueue : public ASensorEventQueue, public RefBase
     51 {
     52 public:
     53 
     54     enum { MAX_RECEIVE_BUFFER_EVENT_COUNT = 256 };
     55 
     56     /**
     57      * Typical sensor delay (sample period) in microseconds.
     58      */
     59     // Fastest sampling, system will bound it to minDelay
     60     static constexpr int32_t SENSOR_DELAY_FASTEST = 0;
     61     // Typical sample period for game, 50Hz;
     62     static constexpr int32_t SENSOR_DELAY_GAME = 20000;
     63     // Typical sample period for UI, 15Hz
     64     static constexpr int32_t SENSOR_DELAY_UI = 66667;
     65     // Default sensor sample period
     66     static constexpr int32_t SENSOR_DELAY_NORMAL = 200000;
     67 
     68     SensorEventQueue(const sp<ISensorEventConnection>& connection);
     69     virtual ~SensorEventQueue();
     70     virtual void onFirstRef();
     71 
     72     int getFd() const;
     73 
     74     static ssize_t write(const sp<BitTube>& tube,
     75             ASensorEvent const* events, size_t numEvents);
     76 
     77     ssize_t read(ASensorEvent* events, size_t numEvents);
     78 
     79     status_t waitForEvent() const;
     80     status_t wake() const;
     81 
     82     status_t enableSensor(Sensor const* sensor) const;
     83     status_t enableSensor(Sensor const* sensor, int32_t samplingPeriodUs) const;
     84     status_t disableSensor(Sensor const* sensor) const;
     85     status_t setEventRate(Sensor const* sensor, nsecs_t ns) const;
     86 
     87     // these are here only to support SensorManager.java
     88     status_t enableSensor(int32_t handle, int32_t samplingPeriodUs, int maxBatchReportLatencyUs,
     89                           int reservedFlags) const;
     90     status_t disableSensor(int32_t handle) const;
     91     status_t flush() const;
     92     // Send an ack for every wake_up sensor event that is set to WAKE_UP_SENSOR_EVENT_NEEDS_ACK.
     93     void sendAck(const ASensorEvent* events, int count);
     94 
     95     status_t injectSensorEvent(const ASensorEvent& event);
     96 private:
     97     sp<Looper> getLooper() const;
     98     sp<ISensorEventConnection> mSensorEventConnection;
     99     sp<BitTube> mSensorChannel;
    100     mutable Mutex mLock;
    101     mutable sp<Looper> mLooper;
    102     ASensorEvent* mRecBuffer;
    103     size_t mAvailable;
    104     size_t mConsumed;
    105     uint32_t mNumAcksToSend;
    106 };
    107 
    108 // ----------------------------------------------------------------------------
    109 }; // namespace android
    110 
    111 #endif // ANDROID_SENSOR_EVENT_QUEUE_H
    112