SensorEventQueue.cpp revision 90ed3e8d7883d9c80fb8bf11b1c593bd8b2b39d0 
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/Looper.h>
25
26#include <gui/Sensor.h>
27#include <gui/BitTube.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), mRecBuffer(NULL), mAvailable(0), mConsumed(0) {
39    mRecBuffer = new ASensorEvent[MAX_RECEIVE_BUFFER_EVENT_COUNT];
40}
41
42SensorEventQueue::~SensorEventQueue() {
43    delete [] mRecBuffer;
44}
45
46void SensorEventQueue::onFirstRef()
47{
48    mSensorChannel = mSensorEventConnection->getSensorChannel();
49}
50
51int SensorEventQueue::getFd() const
52{
53    return mSensorChannel->getFd();
54}
55
56
57ssize_t SensorEventQueue::write(const sp<BitTube>& tube,
58        ASensorEvent const* events, size_t numEvents) {
59    return BitTube::sendObjects(tube, events, numEvents);
60}
61
62ssize_t SensorEventQueue::read(ASensorEvent* events, size_t numEvents) {
63    if (mAvailable == 0) {
64        ssize_t err = BitTube::recvObjects(mSensorChannel,
65                mRecBuffer, MAX_RECEIVE_BUFFER_EVENT_COUNT);
66        if (err < 0) {
67            return err;
68        }
69        mAvailable = err;
70        mConsumed = 0;
71    }
72    size_t count = numEvents < mAvailable ? numEvents : mAvailable;
73    memcpy(events, mRecBuffer + mConsumed, count*sizeof(ASensorEvent));
74    mAvailable -= count;
75    mConsumed += count;
76    return count;
77}
78
79sp<Looper> SensorEventQueue::getLooper() const
80{
81    Mutex::Autolock _l(mLock);
82    if (mLooper == 0) {
83        mLooper = new Looper(true);
84        mLooper->addFd(getFd(), getFd(), ALOOPER_EVENT_INPUT, NULL, NULL);
85    }
86    return mLooper;
87}
88
89status_t SensorEventQueue::waitForEvent() const
90{
91    const int fd = getFd();
92    sp<Looper> looper(getLooper());
93
94    int events;
95    int32_t result;
96    do {
97        result = looper->pollOnce(-1, NULL, &events, NULL);
98        if (result == ALOOPER_POLL_ERROR) {
99            ALOGE("SensorEventQueue::waitForEvent error (errno=%d)", errno);
100            result = -EPIPE; // unknown error, so we make up one
101            break;
102        }
103        if (events & ALOOPER_EVENT_HANGUP) {
104            // the other-side has died
105            ALOGE("SensorEventQueue::waitForEvent error HANGUP");
106            result = -EPIPE; // unknown error, so we make up one
107            break;
108        }
109    } while (result != fd);
110
111    return  (result == fd) ? status_t(NO_ERROR) : result;
112}
113
114status_t SensorEventQueue::wake() const
115{
116    sp<Looper> looper(getLooper());
117    looper->wake();
118    return NO_ERROR;
119}
120
121status_t SensorEventQueue::enableSensor(Sensor const* sensor) const {
122    return mSensorEventConnection->enableDisable(sensor->getHandle(), true, 0, 0, false);
123}
124
125status_t SensorEventQueue::disableSensor(Sensor const* sensor) const {
126    return mSensorEventConnection->enableDisable(sensor->getHandle(), false, 0, 0, false);
127}
128
129status_t SensorEventQueue::enableSensor(int32_t handle, int32_t samplingPeriodUs,
130                                        int maxBatchReportLatencyUs, int reservedFlags) const {
131    return mSensorEventConnection->enableDisable(handle, true, us2ns(samplingPeriodUs),
132                                                 us2ns(maxBatchReportLatencyUs), reservedFlags);
133}
134
135status_t SensorEventQueue::flushSensor(int32_t handle) const {
136    return mSensorEventConnection->flushSensor(handle);
137}
138
139status_t SensorEventQueue::disableSensor(int32_t handle) const {
140    return mSensorEventConnection->enableDisable(handle, false, 0, 0, false);
141}
142
143status_t SensorEventQueue::setEventRate(Sensor const* sensor, nsecs_t ns) const {
144    return mSensorEventConnection->setEventRate(sensor->getHandle(), ns);
145}
146
147// ----------------------------------------------------------------------------
148}; // namespace android
149
150