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      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 // ----------------------------------------------------------------------------
     35 namespace android {
     36 // ----------------------------------------------------------------------------
     37 
     38 SensorEventQueue::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 
     44 SensorEventQueue::~SensorEventQueue() {
     45     delete [] mRecBuffer;
     46 }
     47 
     48 void SensorEventQueue::onFirstRef()
     49 {
     50     mSensorChannel = mSensorEventConnection->getSensorChannel();
     51 }
     52 
     53 int SensorEventQueue::getFd() const
     54 {
     55     return mSensorChannel->getFd();
     56 }
     57 
     58 
     59 ssize_t SensorEventQueue::write(const sp<BitTube>& tube,
     60         ASensorEvent const* events, size_t numEvents) {
     61     return BitTube::sendObjects(tube, events, numEvents);
     62 }
     63 
     64 ssize_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 
     81 sp<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 
     91 status_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 
    116 status_t SensorEventQueue::wake() const
    117 {
    118     sp<Looper> looper(getLooper());
    119     looper->wake();
    120     return NO_ERROR;
    121 }
    122 
    123 status_t SensorEventQueue::enableSensor(Sensor const* sensor) const {
    124     return mSensorEventConnection->enableDisable(sensor->getHandle(), true, 0, 0, false);
    125 }
    126 
    127 status_t SensorEventQueue::disableSensor(Sensor const* sensor) const {
    128     return mSensorEventConnection->enableDisable(sensor->getHandle(), false, 0, 0, false);
    129 }
    130 
    131 status_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 
    137 status_t SensorEventQueue::flush() const {
    138     return mSensorEventConnection->flush();
    139 }
    140 
    141 status_t SensorEventQueue::disableSensor(int32_t handle) const {
    142     return mSensorEventConnection->enableDisable(handle, false, 0, 0, false);
    143 }
    144 
    145 status_t SensorEventQueue::setEventRate(Sensor const* sensor, nsecs_t ns) const {
    146     return mSensorEventConnection->setEventRate(sensor->getHandle(), ns);
    147 }
    148 
    149 void 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