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