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 <algorithm>
20#include <stdint.h>
21#include <sys/types.h>
22#include <sys/socket.h>
23#include <linux/errno.h>
24
25#include <utils/Errors.h>
26#include <utils/RefBase.h>
27#include <utils/Looper.h>
28
29#include <gui/Sensor.h>
30#include <gui/BitTube.h>
31#include <gui/SensorEventQueue.h>
32#include <gui/ISensorEventConnection.h>
33
34#include <android/sensor.h>
35
36using std::min;
37
38// ----------------------------------------------------------------------------
39namespace android {
40// ----------------------------------------------------------------------------
41
42SensorEventQueue::SensorEventQueue(const sp<ISensorEventConnection>& connection)
43    : mSensorEventConnection(connection), mRecBuffer(NULL), mAvailable(0), mConsumed(0),
44      mNumAcksToSend(0) {
45    mRecBuffer = new ASensorEvent[MAX_RECEIVE_BUFFER_EVENT_COUNT];
46}
47
48SensorEventQueue::~SensorEventQueue() {
49    delete [] mRecBuffer;
50}
51
52void SensorEventQueue::onFirstRef()
53{
54    mSensorChannel = mSensorEventConnection->getSensorChannel();
55}
56
57int SensorEventQueue::getFd() const
58{
59    return mSensorChannel->getFd();
60}
61
62
63ssize_t SensorEventQueue::write(const sp<BitTube>& tube,
64        ASensorEvent const* events, size_t numEvents) {
65    return BitTube::sendObjects(tube, events, numEvents);
66}
67
68ssize_t SensorEventQueue::read(ASensorEvent* events, size_t numEvents) {
69    if (mAvailable == 0) {
70        ssize_t err = BitTube::recvObjects(mSensorChannel,
71                mRecBuffer, MAX_RECEIVE_BUFFER_EVENT_COUNT);
72        if (err < 0) {
73            return err;
74        }
75        mAvailable = static_cast<size_t>(err);
76        mConsumed = 0;
77    }
78    size_t count = min(numEvents, mAvailable);
79    memcpy(events, mRecBuffer + mConsumed, count * sizeof(ASensorEvent));
80    mAvailable -= count;
81    mConsumed += count;
82    return static_cast<ssize_t>(count);
83}
84
85sp<Looper> SensorEventQueue::getLooper() const
86{
87    Mutex::Autolock _l(mLock);
88    if (mLooper == 0) {
89        mLooper = new Looper(true);
90        mLooper->addFd(getFd(), getFd(), ALOOPER_EVENT_INPUT, NULL, NULL);
91    }
92    return mLooper;
93}
94
95status_t SensorEventQueue::waitForEvent() const
96{
97    const int fd = getFd();
98    sp<Looper> looper(getLooper());
99
100    int events;
101    int32_t result;
102    do {
103        result = looper->pollOnce(-1, NULL, &events, NULL);
104        if (result == ALOOPER_POLL_ERROR) {
105            ALOGE("SensorEventQueue::waitForEvent error (errno=%d)", errno);
106            result = -EPIPE; // unknown error, so we make up one
107            break;
108        }
109        if (events & ALOOPER_EVENT_HANGUP) {
110            // the other-side has died
111            ALOGE("SensorEventQueue::waitForEvent error HANGUP");
112            result = -EPIPE; // unknown error, so we make up one
113            break;
114        }
115    } while (result != fd);
116
117    return  (result == fd) ? status_t(NO_ERROR) : result;
118}
119
120status_t SensorEventQueue::wake() const
121{
122    sp<Looper> looper(getLooper());
123    looper->wake();
124    return NO_ERROR;
125}
126
127status_t SensorEventQueue::enableSensor(Sensor const* sensor) const {
128    return enableSensor(sensor, SENSOR_DELAY_NORMAL);
129}
130
131status_t SensorEventQueue::enableSensor(Sensor const* sensor, int32_t samplingPeriodUs) const {
132    return mSensorEventConnection->enableDisable(sensor->getHandle(), true,
133                                                 us2ns(samplingPeriodUs), 0, 0);
134}
135
136status_t SensorEventQueue::disableSensor(Sensor const* sensor) const {
137    return mSensorEventConnection->enableDisable(sensor->getHandle(), false, 0, 0, 0);
138}
139
140status_t SensorEventQueue::enableSensor(int32_t handle, int32_t samplingPeriodUs,
141                                        int maxBatchReportLatencyUs, int reservedFlags) const {
142    return mSensorEventConnection->enableDisable(handle, true, us2ns(samplingPeriodUs),
143                                                 us2ns(maxBatchReportLatencyUs), reservedFlags);
144}
145
146status_t SensorEventQueue::flush() const {
147    return mSensorEventConnection->flush();
148}
149
150status_t SensorEventQueue::disableSensor(int32_t handle) const {
151    return mSensorEventConnection->enableDisable(handle, false, 0, 0, false);
152}
153
154status_t SensorEventQueue::setEventRate(Sensor const* sensor, nsecs_t ns) const {
155    return mSensorEventConnection->setEventRate(sensor->getHandle(), ns);
156}
157
158status_t SensorEventQueue::injectSensorEvent(const ASensorEvent& event) {
159    do {
160        // Blocking call.
161        ssize_t size = ::send(mSensorChannel->getFd(), &event, sizeof(event), MSG_NOSIGNAL);
162        if (size >= 0) {
163            return NO_ERROR;
164        } else if (size < 0 && errno == EAGAIN) {
165            // If send is returning a "Try again" error, sleep for 100ms and try again. In all
166            // other cases log a failure and exit.
167            usleep(100000);
168        } else {
169            ALOGE("injectSensorEvent failure %s %zd", strerror(errno), size);
170            return INVALID_OPERATION;
171        }
172    } while (true);
173}
174
175void SensorEventQueue::sendAck(const ASensorEvent* events, int count) {
176    for (int i = 0; i < count; ++i) {
177        if (events[i].flags & WAKE_UP_SENSOR_EVENT_NEEDS_ACK) {
178            ++mNumAcksToSend;
179        }
180    }
181    // Send mNumAcksToSend to acknowledge for the wake up sensor events received.
182    if (mNumAcksToSend > 0) {
183        ssize_t size = ::send(mSensorChannel->getFd(), &mNumAcksToSend, sizeof(mNumAcksToSend),
184                MSG_DONTWAIT | MSG_NOSIGNAL);
185        if (size < 0) {
186            ALOGE("sendAck failure %zd %d", size, mNumAcksToSend);
187        } else {
188            mNumAcksToSend = 0;
189        }
190    }
191    return;
192}
193
194// ----------------------------------------------------------------------------
195}; // namespace android
196
197