libs/gui/SensorManager.cpp

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "Sensors"

#include <stdint.h>
#include <sys/types.h>

#include <utils/Errors.h>
#include <utils/RefBase.h>
#include <utils/Singleton.h>

#include <binder/IBinder.h>
#include <binder/IServiceManager.h>

#include <gui/ISensorServer.h>
#include <gui/ISensorEventConnection.h>
#include <gui/Sensor.h>
#include <gui/SensorManager.h>
#include <gui/SensorEventQueue.h>

// ----------------------------------------------------------------------------
namespace android {
// ----------------------------------------------------------------------------

android::Mutex android::SensorManager::sLock;
std::map<String16, SensorManager*> android::SensorManager::sPackageInstances;

SensorManager& SensorManager::getInstanceForPackage(const String16& packageName) {
    Mutex::Autolock _l(sLock);
    SensorManager* sensorManager;
    std::map<String16, SensorManager*>::iterator iterator =
        sPackageInstances.find(packageName);

    if (iterator != sPackageInstances.end()) {
        sensorManager = iterator->second;
    } else {
        String16 opPackageName = packageName;

        // It is possible that the calling code has no access to the package name.
        // In this case we will get the packages for the calling UID and pick the
        // first one for attributing the app op. This will work correctly for
        // runtime permissions as for legacy apps we will toggle the app op for
        // all packages in the UID. The caveat is that the operation may be attributed
        // to the wrong package and stats based on app ops may be slightly off.
        if (opPackageName.size() <= 0) {
            sp<IBinder> binder = defaultServiceManager()->getService(String16("permission"));
            if (binder != 0) {
                const uid_t uid = IPCThreadState::self()->getCallingUid();
                Vector<String16> packages;
                interface_cast<IPermissionController>(binder)->getPackagesForUid(uid, packages);
                if (!packages.isEmpty()) {
                    opPackageName = packages[0];
                } else {
                    ALOGE("No packages for calling UID");
                }
            } else {
                ALOGE("Cannot get permission service");
            }
        }

        sensorManager = new SensorManager(opPackageName);

        // If we had no package name, we looked it up from the UID and the sensor
        // manager instance we created should also be mapped to the empty package
        // name, to avoid looking up the packages for a UID and get the same result.
        if (packageName.size() <= 0) {
            sPackageInstances.insert(std::make_pair(String16(), sensorManager));
        }

        // Stash the per package sensor manager.
        sPackageInstances.insert(std::make_pair(opPackageName, sensorManager));
    }

    return *sensorManager;
}

SensorManager::SensorManager(const String16& opPackageName)
    : mSensorList(NULL), mAvailableSensorList(NULL), mNumAvailableSensor(0),
      mOpPackageName(opPackageName), mBodyPermission(false)
{
    // okay we're not locked here, but it's not needed during construction
    assertStateLocked();
}

SensorManager::~SensorManager()
{
    free(mSensorList);
    if (mAvailableSensorList) {
        free(mAvailableSensorList);
    }
}

void SensorManager::sensorManagerDied()
{
    Mutex::Autolock _l(mLock);
    mSensorServer.clear();
    free(mSensorList);
    mSensorList = NULL;
    if (mAvailableSensorList) {
        free(mAvailableSensorList);
        mAvailableSensorList = NULL;
    }
    mSensors.clear();
}

status_t SensorManager::assertStateLocked() {
    bool initSensorManager = false;
    if (mSensorServer == NULL) {
        initSensorManager = true;
    } else {
        // Ping binder to check if sensorservice is alive.
        status_t err = IInterface::asBinder(mSensorServer)->pingBinder();
        if (err != NO_ERROR) {
            initSensorManager = true;
        }
    }
    if (initSensorManager) {
        // try for 300 seconds (60*5(getService() tries for 5 seconds)) before giving up ...
        const String16 name("sensorservice");
        for (int i = 0; i < 60; i++) {
            status_t err = getService(name, &mSensorServer);
            if (err == NAME_NOT_FOUND) {
                sleep(1);
                continue;
            }
            if (err != NO_ERROR) {
                return err;
            }
            break;
        }

        class DeathObserver : public IBinder::DeathRecipient {
            SensorManager& mSensorManger;
            virtual void binderDied(const wp<IBinder>& who) {
                ALOGW("sensorservice died [%p]", who.unsafe_get());
                mSensorManger.sensorManagerDied();
            }
        public:
            DeathObserver(SensorManager& mgr) : mSensorManger(mgr) { }
        };

        LOG_ALWAYS_FATAL_IF(mSensorServer.get() == NULL, "getService(SensorService) NULL");

        mDeathObserver = new DeathObserver(*const_cast<SensorManager *>(this));
        IInterface::asBinder(mSensorServer)->linkToDeath(mDeathObserver);

        mSensors = mSensorServer->getSensorList(mOpPackageName);
        size_t count = mSensors.size();
        mSensorList =
                static_cast<Sensor const**>(malloc(count * sizeof(Sensor*)));
        LOG_ALWAYS_FATAL_IF(mSensorList == NULL, "mSensorList NULL");

        for (size_t i=0 ; i<count ; i++) {
            mSensorList[i] = mSensors.array() + i;
        }

        updateAvailableSensorList();
    }

    return NO_ERROR;
}

ssize_t SensorManager::getSensorList(Sensor const* const** list) {
    Mutex::Autolock _l(mLock);
    status_t err = assertStateLocked();
    if (err < 0) {
        return static_cast<ssize_t>(err);
    }
    *list = mSensorList;
    return static_cast<ssize_t>(mSensors.size());
}

void SensorManager::updateAvailableSensorList() {
    const int uid = static_cast<int>(IPCThreadState::self()->getCallingUid());
    const int pid = static_cast<int>(IPCThreadState::self()->getCallingPid());
    const String16 BODY_SENSOR_PERMISSION("android.permission.BODY_SENSORS");
    const String8 BODY_SENSOR_PERMISSION8("android.permission.BODY_SENSORS");

    bool bodySensorPermission = false;

    sp<IBinder> binder = defaultServiceManager()->getService(String16("permission"));
    if (binder != NULL) {
        bodySensorPermission = interface_cast<IPermissionController>(binder)->
                checkPermission(BODY_SENSOR_PERMISSION, pid, uid);
    }

    // only update if app got BODY_SENSORS permission after last call or the sensor list has not
    // been populated.
    //
    // it is not possible for the reverse transition, as the app will be killed when permission is
    // revoked.
    if ( (bodySensorPermission && !mBodyPermission) || mAvailableSensorList == NULL) {

        // allocate only when necessary
        if (mAvailableSensorList == NULL) {
            // allocate a list big enough to fit all sensors (including those requires permission
            // that the app do not have;
            mAvailableSensorList =
                    static_cast<Sensor const**>(malloc(mSensors.size() * sizeof(Sensor*)));

            // first populate all sensors that do not need body sensor permission
            ssize_t& n = mNumAvailableSensor;
            for (size_t i = 0; i < mSensors.size() ; i++) {
                if (mSensors[i].getRequiredPermission() != BODY_SENSOR_PERMISSION8) {
                    mAvailableSensorList[n++] = mSensors.array() + i;
                }
            }
        }

        if (bodySensorPermission) {
            // if the app just got the sensor permission back, fill the sensor at the end of list
            ssize_t& n = mNumAvailableSensor;
            for (size_t i = 0; i < mSensors.size() ; i++) {
                if (mSensors[i].getRequiredPermission() == BODY_SENSOR_PERMISSION8) {
                    mAvailableSensorList[n++] = mSensors.array() + i;
                }
            }
        }

        mBodyPermission = bodySensorPermission;
    }
}

ssize_t SensorManager::getAvailableSensorList(Sensor const* const** list) {
    Mutex::Autolock _l(mLock);
    status_t err = assertStateLocked();
    if (err < 0) {
        return static_cast<ssize_t>(err);
    }

    updateAvailableSensorList();

    *list = mAvailableSensorList;
    return mNumAvailableSensor;
}

Sensor const* SensorManager::getDefaultSensor(int type) {
    Mutex::Autolock _l(mLock);
    if (assertStateLocked() == NO_ERROR) {

        updateAvailableSensorList();

        bool wakeUpSensor = false;
        // For the following sensor types, return a wake-up sensor. These types are by default
        // defined as wake-up sensors. For the rest of the sensor types defined in sensors.h return
        // a non_wake-up version.
        if (type == SENSOR_TYPE_PROXIMITY || type == SENSOR_TYPE_SIGNIFICANT_MOTION ||
            type == SENSOR_TYPE_TILT_DETECTOR || type == SENSOR_TYPE_WAKE_GESTURE ||
            type == SENSOR_TYPE_GLANCE_GESTURE || type == SENSOR_TYPE_PICK_UP_GESTURE) {
            wakeUpSensor = true;
        }
        // For now we just return the first sensor of that type we find.
        // in the future it will make sense to let the SensorService make
        // that decision.
        for (size_t i=0 ; i<mSensors.size() ; i++) {
            if (mAvailableSensorList[i]->getType() == type &&
                mAvailableSensorList[i]->isWakeUpSensor() == wakeUpSensor) {
                return mAvailableSensorList[i];
            }
        }
    }
    return NULL;
}

sp<SensorEventQueue> SensorManager::createEventQueue(String8 packageName, int mode) {
    sp<SensorEventQueue> queue;

    Mutex::Autolock _l(mLock);
    while (assertStateLocked() == NO_ERROR) {
        sp<ISensorEventConnection> connection =
                mSensorServer->createSensorEventConnection(packageName, mode, mOpPackageName);
        if (connection == NULL) {
            // SensorService just died or the app doesn't have required permissions.
            ALOGE("createEventQueue: connection is NULL.");
            return NULL;
        }
        queue = new SensorEventQueue(connection);
        break;
    }
    return queue;
}

bool SensorManager::isDataInjectionEnabled() {
    Mutex::Autolock _l(mLock);
    if (assertStateLocked() == NO_ERROR) {
        return mSensorServer->isDataInjectionEnabled();
    }
    return false;
}

// ----------------------------------------------------------------------------
}; // namespace android