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     SensorEventQueue(const sp<ISensorEventConnection>& connection);
57     virtual ~SensorEventQueue();
58     virtual void onFirstRef();
59 
60     int getFd() const;
61 
62     static ssize_t write(const sp<BitTube>& tube,
63             ASensorEvent const* events, size_t numEvents);
64 
65     ssize_t read(ASensorEvent* events, size_t numEvents);
66 
67     status_t waitForEvent() const;
68     status_t wake() const;
69 
70     status_t enableSensor(Sensor const* sensor) const;
71     status_t disableSensor(Sensor const* sensor) const;
72     status_t setEventRate(Sensor const* sensor, nsecs_t ns) const;
73 
74     // these are here only to support SensorManager.java
75     status_t enableSensor(int32_t handle, int32_t samplingPeriodUs, int maxBatchReportLatencyUs,
76                           int reservedFlags) const;
77     status_t disableSensor(int32_t handle) const;
78     status_t flush() const;
79     // Send an ack for every wake_up sensor event that is set to WAKE_UP_SENSOR_EVENT_NEEDS_ACK.
80     void sendAck(const ASensorEvent* events, int count);
81 
82     status_t injectSensorEvent(const ASensorEvent& event);
83 private:
84     sp<Looper> getLooper() const;
85     sp<ISensorEventConnection> mSensorEventConnection;
86     sp<BitTube> mSensorChannel;
87     mutable Mutex mLock;
88     mutable sp<Looper> mLooper;
89     ASensorEvent* mRecBuffer;
90     size_t mAvailable;
91     size_t mConsumed;
92     uint32_t mNumAcksToSend;
93 };
94 
95 // ----------------------------------------------------------------------------
96 }; // namespace android
97 
98 #endif // ANDROID_SENSOR_EVENT_QUEUE_H
99