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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 
     22 #include <utils/Errors.h>
     23 #include <utils/RefBase.h>
     24 #include <utils/Singleton.h>
     25 
     26 #include <binder/IBinder.h>
     27 #include <binder/IServiceManager.h>
     28 
     29 #include <gui/ISensorServer.h>
     30 #include <gui/ISensorEventConnection.h>
     31 #include <gui/Sensor.h>
     32 #include <gui/SensorManager.h>
     33 #include <gui/SensorEventQueue.h>
     34 
     35 // ----------------------------------------------------------------------------
     36 namespace android {
     37 // ----------------------------------------------------------------------------
     38 
     39 ANDROID_SINGLETON_STATIC_INSTANCE(SensorManager)
     40 
     41 SensorManager::SensorManager()
     42     : mSensorList(0)
     43 {
     44     // okay we're not locked here, but it's not needed during construction
     45     assertStateLocked();
     46 }
     47 
     48 SensorManager::~SensorManager()
     49 {
     50     free(mSensorList);
     51 }
     52 
     53 void SensorManager::sensorManagerDied()
     54 {
     55     Mutex::Autolock _l(mLock);
     56     mSensorServer.clear();
     57     free(mSensorList);
     58     mSensorList = NULL;
     59     mSensors.clear();
     60 }
     61 
     62 status_t SensorManager::assertStateLocked() const {
     63     if (mSensorServer == NULL) {
     64         // try for one second
     65         const String16 name("sensorservice");
     66         for (int i=0 ; i<4 ; i++) {
     67             status_t err = getService(name, &mSensorServer);
     68             if (err == NAME_NOT_FOUND) {
     69                 usleep(250000);
     70                 continue;
     71             }
     72             if (err != NO_ERROR) {
     73                 return err;
     74             }
     75             break;
     76         }
     77 
     78         class DeathObserver : public IBinder::DeathRecipient {
     79             SensorManager& mSensorManger;
     80             virtual void binderDied(const wp<IBinder>& who) {
     81                 ALOGW("sensorservice died [%p]", who.unsafe_get());
     82                 mSensorManger.sensorManagerDied();
     83             }
     84         public:
     85             DeathObserver(SensorManager& mgr) : mSensorManger(mgr) { }
     86         };
     87 
     88         mDeathObserver = new DeathObserver(*const_cast<SensorManager *>(this));
     89         mSensorServer->asBinder()->linkToDeath(mDeathObserver);
     90 
     91         mSensors = mSensorServer->getSensorList();
     92         size_t count = mSensors.size();
     93         mSensorList = (Sensor const**)malloc(count * sizeof(Sensor*));
     94         for (size_t i=0 ; i<count ; i++) {
     95             mSensorList[i] = mSensors.array() + i;
     96         }
     97     }
     98 
     99     return NO_ERROR;
    100 }
    101 
    102 
    103 
    104 ssize_t SensorManager::getSensorList(Sensor const* const** list) const
    105 {
    106     Mutex::Autolock _l(mLock);
    107     status_t err = assertStateLocked();
    108     if (err < 0) {
    109         return ssize_t(err);
    110     }
    111     *list = mSensorList;
    112     return mSensors.size();
    113 }
    114 
    115 Sensor const* SensorManager::getDefaultSensor(int type)
    116 {
    117     Mutex::Autolock _l(mLock);
    118     if (assertStateLocked() == NO_ERROR) {
    119         // For now we just return the first sensor of that type we find.
    120         // in the future it will make sense to let the SensorService make
    121         // that decision.
    122         for (size_t i=0 ; i<mSensors.size() ; i++) {
    123             if (mSensorList[i]->getType() == type)
    124                 return mSensorList[i];
    125         }
    126     }
    127     return NULL;
    128 }
    129 
    130 sp<SensorEventQueue> SensorManager::createEventQueue()
    131 {
    132     sp<SensorEventQueue> queue;
    133 
    134     Mutex::Autolock _l(mLock);
    135     while (assertStateLocked() == NO_ERROR) {
    136         sp<ISensorEventConnection> connection =
    137                 mSensorServer->createSensorEventConnection();
    138         if (connection == NULL) {
    139             // SensorService just died.
    140             ALOGE("createEventQueue: connection is NULL. SensorService died.");
    141             continue;
    142         }
    143         queue = new SensorEventQueue(connection);
    144         break;
    145     }
    146     return queue;
    147 }
    148 
    149 // ----------------------------------------------------------------------------
    150 }; // namespace android
    151