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 #pragma once
18 
19 #include <stdint.h>
20 #include <sys/types.h>
21 
22 #include <utils/Errors.h>
23 #include <utils/RefBase.h>
24 #include <utils/Timers.h>
25 #include <utils/Mutex.h>
26 
27 #include <sensor/BitTube.h>
28 
29 // ----------------------------------------------------------------------------
30 #define WAKE_UP_SENSOR_EVENT_NEEDS_ACK (1U << 31)
31 struct ALooper;
32 struct ASensorEvent;
33 
34 // Concrete types for the NDK
35 struct ASensorEventQueue {
36     ALooper* looper;
37 };
38 
39 // ----------------------------------------------------------------------------
40 namespace android {
41 // ----------------------------------------------------------------------------
42 
43 class ISensorEventConnection;
44 class Sensor;
45 class Looper;
46 
47 // ----------------------------------------------------------------------------
48 
49 class SensorEventQueue : public ASensorEventQueue, public RefBase
50 {
51 public:
52 
53     enum { MAX_RECEIVE_BUFFER_EVENT_COUNT = 256 };
54 
55     /**
56      * Typical sensor delay (sample period) in microseconds.
57      */
58     // Fastest sampling, system will bound it to minDelay
59     static constexpr int32_t SENSOR_DELAY_FASTEST = 0;
60     // Typical sample period for game, 50Hz;
61     static constexpr int32_t SENSOR_DELAY_GAME = 20000;
62     // Typical sample period for UI, 15Hz
63     static constexpr int32_t SENSOR_DELAY_UI = 66667;
64     // Default sensor sample period
65     static constexpr int32_t SENSOR_DELAY_NORMAL = 200000;
66 
67     SensorEventQueue(const sp<ISensorEventConnection>& connection);
68     virtual ~SensorEventQueue();
69     virtual void onFirstRef();
70 
71     int getFd() const;
72 
73     static ssize_t write(const sp<BitTube>& tube,
74             ASensorEvent const* events, size_t numEvents);
75 
76     ssize_t read(ASensorEvent* events, size_t numEvents);
77 
78     status_t waitForEvent() const;
79     status_t wake() const;
80 
81     status_t enableSensor(Sensor const* sensor) const;
82     status_t enableSensor(Sensor const* sensor, int32_t samplingPeriodUs) const;
83     status_t disableSensor(Sensor const* sensor) const;
84     status_t setEventRate(Sensor const* sensor, nsecs_t ns) const;
85 
86     // these are here only to support SensorManager.java and HIDL Frameworks SensorManager.
87     status_t enableSensor(int32_t handle, int32_t samplingPeriodUs, int64_t maxBatchReportLatencyUs,
88                           int reservedFlags) const;
89     status_t disableSensor(int32_t handle) const;
90     status_t flush() const;
91     // Send an ack for every wake_up sensor event that is set to WAKE_UP_SENSOR_EVENT_NEEDS_ACK.
92     void sendAck(const ASensorEvent* events, int count);
93 
94     status_t injectSensorEvent(const ASensorEvent& event);
95 private:
96     sp<Looper> getLooper() const;
97     sp<ISensorEventConnection> mSensorEventConnection;
98     sp<BitTube> mSensorChannel;
99     mutable Mutex mLock;
100     mutable sp<Looper> mLooper;
101     ASensorEvent* mRecBuffer;
102     size_t mAvailable;
103     size_t mConsumed;
104     uint32_t mNumAcksToSend;
105 };
106 
107 // ----------------------------------------------------------------------------
108 }; // namespace android
109