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)
32struct ALooper;
33struct ASensorEvent;
34
35// Concrete types for the NDK
36struct ASensorEventQueue {
37    ALooper* looper;
38};
39
40// ----------------------------------------------------------------------------
41namespace android {
42// ----------------------------------------------------------------------------
43
44class ISensorEventConnection;
45class Sensor;
46class Looper;
47
48// ----------------------------------------------------------------------------
49
50class SensorEventQueue : public ASensorEventQueue, public RefBase
51{
52public:
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);
96private:
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