SensorService.h revision 9a844cf78f09953145200b4074d47589257a408c 
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_SERVICE_H
18#define ANDROID_SENSOR_SERVICE_H
19
20#include <stdint.h>
21#include <sys/types.h>
22
23#include <utils/Vector.h>
24#include <utils/SortedVector.h>
25#include <utils/KeyedVector.h>
26#include <utils/threads.h>
27#include <utils/RefBase.h>
28
29#include <binder/BinderService.h>
30
31#include <gui/Sensor.h>
32#include <gui/BitTube.h>
33#include <gui/ISensorServer.h>
34#include <gui/ISensorEventConnection.h>
35
36#include "SensorInterface.h"
37
38// ---------------------------------------------------------------------------
39
40#define DEBUG_CONNECTIONS   false
41// Max size is 1 MB which is enough to accept a batch of about 10k events.
42#define MAX_SOCKET_BUFFER_SIZE_BATCHED 1024 * 1024
43#define SOCKET_BUFFER_SIZE_NON_BATCHED 4 * 1024
44#define WAKE_UP_SENSOR_EVENT_NEEDS_ACK (1 << 31)
45
46struct sensors_poll_device_t;
47struct sensors_module_t;
48
49namespace android {
50// ---------------------------------------------------------------------------
51
52class SensorService :
53        public BinderService<SensorService>,
54        public BnSensorServer,
55        protected Thread
56{
57    friend class BinderService<SensorService>;
58
59    static const char* WAKE_LOCK_NAME;
60
61    static char const* getServiceName() ANDROID_API { return "sensorservice"; }
62    SensorService() ANDROID_API;
63    virtual ~SensorService();
64
65    virtual void onFirstRef();
66
67    // Thread interface
68    virtual bool threadLoop();
69
70    // ISensorServer interface
71    virtual Vector<Sensor> getSensorList();
72    virtual sp<ISensorEventConnection> createSensorEventConnection();
73    virtual status_t dump(int fd, const Vector<String16>& args);
74
75    class SensorEventConnection : public BnSensorEventConnection {
76        virtual ~SensorEventConnection();
77        virtual void onFirstRef();
78        virtual sp<BitTube> getSensorChannel() const;
79        virtual status_t enableDisable(int handle, bool enabled, nsecs_t samplingPeriodNs,
80                                       nsecs_t maxBatchReportLatencyNs, int reservedFlags);
81        virtual status_t setEventRate(int handle, nsecs_t samplingPeriodNs);
82        virtual status_t flush();
83        void decreaseWakeLockRefCount();
84        // Count the number of flush complete events which are about to be dropped in the buffer.
85        // Increment mPendingFlushEventsToSend in mSensorInfo. These flush complete events will be
86        // sent separately before the next batch of events.
87        void countFlushCompleteEventsLocked(sensors_event_t* scratch, int numEventsDropped);
88
89        // Check if there are any wake up events in the buffer. If yes, increment the ref count.
90        // Increment it by exactly one unit for each packet sent on the socket. SOCK_SEQPACKET for
91        // the socket ensures that either the entire packet is read or dropped.
92        // Return 1 if mWakeLockRefCount has been incremented, zero if not.
93        int countWakeUpSensorEventsLocked(sensors_event_t* scratch, const int count);
94
95        sp<SensorService> const mService;
96        sp<BitTube> mChannel;
97        uid_t mUid;
98        mutable Mutex mConnectionLock;
99        // Number of events from wake up sensors which are still pending and haven't been delivered
100        // to the corresponding application. It is incremented by one unit for each write to the
101        // socket.
102        int mWakeLockRefCount;
103
104        struct FlushInfo {
105            // The number of flush complete events dropped for this sensor is stored here.
106            // They are sent separately before the next batch of events.
107            int mPendingFlushEventsToSend;
108            // Every activate is preceded by a flush. Only after the first flush complete is
109            // received, the events for the sensor are sent on that *connection*.
110            bool mFirstFlushPending;
111            FlushInfo() : mPendingFlushEventsToSend(0), mFirstFlushPending(false) {}
112        };
113        // protected by SensorService::mLock. Key for this vector is the sensor handle.
114        KeyedVector<int, FlushInfo> mSensorInfo;
115
116    public:
117        SensorEventConnection(const sp<SensorService>& service, uid_t uid);
118
119        status_t sendEvents(sensors_event_t const* buffer, size_t count,
120                sensors_event_t* scratch);
121        bool hasSensor(int32_t handle) const;
122        bool hasAnySensor() const;
123        bool addSensor(int32_t handle);
124        bool removeSensor(int32_t handle);
125        void setFirstFlushPending(int32_t handle, bool value);
126        void dump(String8& result);
127        bool needsWakeLock();
128
129        uid_t getUid() const { return mUid; }
130    };
131
132    class SensorRecord {
133        SortedVector< wp<SensorEventConnection> > mConnections;
134    public:
135        SensorRecord(const sp<SensorEventConnection>& connection);
136        bool addConnection(const sp<SensorEventConnection>& connection);
137        bool removeConnection(const wp<SensorEventConnection>& connection);
138        size_t getNumConnections() const { return mConnections.size(); }
139    };
140
141    String8 getSensorName(int handle) const;
142    bool isVirtualSensor(int handle) const;
143    Sensor getSensorFromHandle(int handle) const;
144    bool isWakeUpSensor(int type) const;
145    void recordLastValueLocked(const sensors_event_t* buffer, size_t count);
146    static void sortEventBuffer(sensors_event_t* buffer, size_t count);
147    Sensor registerSensor(SensorInterface* sensor);
148    Sensor registerVirtualSensor(SensorInterface* sensor);
149    status_t cleanupWithoutDisable(
150            const sp<SensorEventConnection>& connection, int handle);
151    status_t cleanupWithoutDisableLocked(
152            const sp<SensorEventConnection>& connection, int handle);
153    void cleanupAutoDisabledSensorLocked(const sp<SensorEventConnection>& connection,
154            sensors_event_t const* buffer, const int count);
155    static bool canAccessSensor(const Sensor& sensor);
156    static bool verifyCanAccessSensor(const Sensor& sensor, const char* operation);
157    // SensorService acquires a partial wakelock for delivering events from wake up sensors. This
158    // method checks whether all the events from these wake up sensors have been delivered to the
159    // corresponding applications, if yes the wakelock is released.
160    void checkWakeLockState();
161    void checkWakeLockStateLocked();
162    bool isWakeUpSensorEvent(const sensors_event_t& event) const;
163    // constants
164    Vector<Sensor> mSensorList;
165    Vector<Sensor> mUserSensorListDebug;
166    Vector<Sensor> mUserSensorList;
167    DefaultKeyedVector<int, SensorInterface*> mSensorMap;
168    Vector<SensorInterface *> mVirtualSensorList;
169    status_t mInitCheck;
170    size_t mSocketBufferSize;
171
172    // protected by mLock
173    mutable Mutex mLock;
174    DefaultKeyedVector<int, SensorRecord*> mActiveSensors;
175    DefaultKeyedVector<int, SensorInterface*> mActiveVirtualSensors;
176    SortedVector< wp<SensorEventConnection> > mActiveConnections;
177    bool mWakeLockAcquired;
178
179    // The size of this vector is constant, only the items are mutable
180    KeyedVector<int32_t, sensors_event_t> mLastEventSeen;
181
182public:
183    void cleanupConnection(SensorEventConnection* connection);
184    status_t enable(const sp<SensorEventConnection>& connection, int handle,
185                    nsecs_t samplingPeriodNs,  nsecs_t maxBatchReportLatencyNs, int reservedFlags);
186    status_t disable(const sp<SensorEventConnection>& connection, int handle);
187    status_t setEventRate(const sp<SensorEventConnection>& connection, int handle, nsecs_t ns);
188    status_t flushSensor(const sp<SensorEventConnection>& connection, int handle);
189};
190
191// ---------------------------------------------------------------------------
192}; // namespace android
193
194#endif // ANDROID_SENSOR_SERVICE_H
195