SensorEventQueue.cpp revision a7352c9f4a6e642c29782b19db5bc0bd98feddc8 
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#define LOG_TAG "Sensors"
18
19#include <stdint.h>
20#include <sys/types.h>
21
22#include <utils/Errors.h>
23#include <utils/RefBase.h>
24#include <utils/PollLoop.h>
25
26#include <gui/Sensor.h>
27#include <gui/SensorChannel.h>
28#include <gui/SensorEventQueue.h>
29#include <gui/ISensorEventConnection.h>
30
31#include <android/sensor.h>
32
33// ----------------------------------------------------------------------------
34namespace android {
35// ----------------------------------------------------------------------------
36
37SensorEventQueue::SensorEventQueue(const sp<ISensorEventConnection>& connection)
38    : mSensorEventConnection(connection)
39{
40}
41
42SensorEventQueue::~SensorEventQueue()
43{
44}
45
46void SensorEventQueue::onFirstRef()
47{
48    mSensorChannel = mSensorEventConnection->getSensorChannel();
49}
50
51int SensorEventQueue::getFd() const
52{
53    return mSensorChannel->getFd();
54}
55
56ssize_t SensorEventQueue::write(ASensorEvent const* events, size_t numEvents)
57{
58    ssize_t size = mSensorChannel->write(events, numEvents * sizeof(events[0]));
59    if (size >= 0) {
60        if (size % sizeof(events[0])) {
61            // partial write!!! should never happen.
62            return -EINVAL;
63        }
64        // returns number of events written
65        size /= sizeof(events[0]);
66    }
67    return size;
68}
69
70ssize_t SensorEventQueue::read(ASensorEvent* events, size_t numEvents)
71{
72    ssize_t size = mSensorChannel->read(events, numEvents*sizeof(events[0]));
73    if (size >= 0) {
74        if (size % sizeof(events[0])) {
75            // partial read!!! should never happen.
76            return -EINVAL;
77        }
78        // returns number of events read
79        size /= sizeof(events[0]);
80    }
81    return size;
82}
83
84sp<PollLoop> SensorEventQueue::getPollLoop() const
85{
86    Mutex::Autolock _l(mLock);
87    if (mPollLoop == 0) {
88        mPollLoop = new PollLoop(true);
89        mPollLoop->setCallback(getFd(), POLLIN, NULL, NULL);
90    }
91    return mPollLoop;
92}
93
94status_t SensorEventQueue::waitForEvent() const
95{
96    const int fd = getFd();
97    sp<PollLoop> pollLoop(getPollLoop());
98    int32_t result = pollLoop->pollOnce(-1, NULL, NULL);
99    return (result == fd) ? NO_ERROR : -1;
100}
101
102status_t SensorEventQueue::wake() const
103{
104    sp<PollLoop> pollLoop(getPollLoop());
105    pollLoop->wake();
106    return NO_ERROR;
107}
108
109status_t SensorEventQueue::enableSensor(Sensor const* sensor) const {
110    return mSensorEventConnection->enableDisable(sensor->getHandle(), true);
111}
112
113status_t SensorEventQueue::disableSensor(Sensor const* sensor) const {
114    return mSensorEventConnection->enableDisable(sensor->getHandle(), false);
115}
116
117status_t SensorEventQueue::enableSensor(int32_t handle) const {
118    return mSensorEventConnection->enableDisable(handle, true);
119}
120
121status_t SensorEventQueue::disableSensor(int32_t handle) const {
122    return mSensorEventConnection->enableDisable(handle, false);
123}
124
125status_t SensorEventQueue::setEventRate(Sensor const* sensor, nsecs_t ns) const {
126    return mSensorEventConnection->setEventRate(sensor->getHandle(), ns);
127}
128
129// ----------------------------------------------------------------------------
130}; // namespace android
131
132