SensorEventQueue.cpp revision 8a96955c8e14db40b16164236830fc9506a00872 
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#include <sys/socket.h>
22
23#include <utils/Errors.h>
24#include <utils/RefBase.h>
25#include <utils/Looper.h>
26
27#include <gui/Sensor.h>
28#include <gui/BitTube.h>
29#include <gui/SensorEventQueue.h>
30#include <gui/ISensorEventConnection.h>
31
32#include <android/sensor.h>
33
34// ----------------------------------------------------------------------------
35namespace android {
36// ----------------------------------------------------------------------------
37
38SensorEventQueue::SensorEventQueue(const sp<ISensorEventConnection>& connection)
39    : mSensorEventConnection(connection), mRecBuffer(NULL), mAvailable(0), mConsumed(0),
40      mNumAcksToSend(0) {
41    mRecBuffer = new ASensorEvent[MAX_RECEIVE_BUFFER_EVENT_COUNT];
42}
43
44SensorEventQueue::~SensorEventQueue() {
45    delete [] mRecBuffer;
46}
47
48void SensorEventQueue::onFirstRef()
49{
50    mSensorChannel = mSensorEventConnection->getSensorChannel();
51}
52
53int SensorEventQueue::getFd() const
54{
55    return mSensorChannel->getFd();
56}
57
58
59ssize_t SensorEventQueue::write(const sp<BitTube>& tube,
60        ASensorEvent const* events, size_t numEvents) {
61    return BitTube::sendObjects(tube, events, numEvents);
62}
63
64ssize_t SensorEventQueue::read(ASensorEvent* events, size_t numEvents) {
65    if (mAvailable == 0) {
66        ssize_t err = BitTube::recvObjects(mSensorChannel,
67                mRecBuffer, MAX_RECEIVE_BUFFER_EVENT_COUNT);
68        if (err < 0) {
69            return err;
70        }
71        mAvailable = err;
72        mConsumed = 0;
73    }
74    size_t count = numEvents < mAvailable ? numEvents : mAvailable;
75    memcpy(events, mRecBuffer + mConsumed, count*sizeof(ASensorEvent));
76    mAvailable -= count;
77    mConsumed += count;
78    return count;
79}
80
81sp<Looper> SensorEventQueue::getLooper() const
82{
83    Mutex::Autolock _l(mLock);
84    if (mLooper == 0) {
85        mLooper = new Looper(true);
86        mLooper->addFd(getFd(), getFd(), ALOOPER_EVENT_INPUT, NULL, NULL);
87    }
88    return mLooper;
89}
90
91status_t SensorEventQueue::waitForEvent() const
92{
93    const int fd = getFd();
94    sp<Looper> looper(getLooper());
95
96    int events;
97    int32_t result;
98    do {
99        result = looper->pollOnce(-1, NULL, &events, NULL);
100        if (result == ALOOPER_POLL_ERROR) {
101            ALOGE("SensorEventQueue::waitForEvent error (errno=%d)", errno);
102            result = -EPIPE; // unknown error, so we make up one
103            break;
104        }
105        if (events & ALOOPER_EVENT_HANGUP) {
106            // the other-side has died
107            ALOGE("SensorEventQueue::waitForEvent error HANGUP");
108            result = -EPIPE; // unknown error, so we make up one
109            break;
110        }
111    } while (result != fd);
112
113    return  (result == fd) ? status_t(NO_ERROR) : result;
114}
115
116status_t SensorEventQueue::wake() const
117{
118    sp<Looper> looper(getLooper());
119    looper->wake();
120    return NO_ERROR;
121}
122
123status_t SensorEventQueue::enableSensor(Sensor const* sensor) const {
124    return mSensorEventConnection->enableDisable(sensor->getHandle(), true, 0, 0, false);
125}
126
127status_t SensorEventQueue::disableSensor(Sensor const* sensor) const {
128    return mSensorEventConnection->enableDisable(sensor->getHandle(), false, 0, 0, false);
129}
130
131status_t SensorEventQueue::enableSensor(int32_t handle, int32_t samplingPeriodUs,
132                                        int maxBatchReportLatencyUs, int reservedFlags) const {
133    return mSensorEventConnection->enableDisable(handle, true, us2ns(samplingPeriodUs),
134                                                 us2ns(maxBatchReportLatencyUs), reservedFlags);
135}
136
137status_t SensorEventQueue::flush() const {
138    return mSensorEventConnection->flush();
139}
140
141status_t SensorEventQueue::disableSensor(int32_t handle) const {
142    return mSensorEventConnection->enableDisable(handle, false, 0, 0, false);
143}
144
145status_t SensorEventQueue::setEventRate(Sensor const* sensor, nsecs_t ns) const {
146    return mSensorEventConnection->setEventRate(sensor->getHandle(), ns);
147}
148
149void SensorEventQueue::sendAck(const ASensorEvent* events, int count) {
150    for (int i = 0; i < count; ++i) {
151        if (events[i].flags & WAKE_UP_SENSOR_EVENT_NEEDS_ACK) {
152            ++mNumAcksToSend;
153        }
154    }
155    // Send mNumAcksToSend to acknowledge for the wake up sensor events received.
156    if (mNumAcksToSend > 0) {
157        ssize_t size = ::send(mSensorChannel->getFd(), &mNumAcksToSend, sizeof(mNumAcksToSend),
158                MSG_DONTWAIT | MSG_NOSIGNAL);
159        if (size < 0) {
160            ALOGE("sendAck failure %d %d", size, mNumAcksToSend);
161        } else {
162            mNumAcksToSend = 0;
163        }
164    }
165    return;
166}
167
168// ----------------------------------------------------------------------------
169}; // namespace android
170
171