diff options
author | BogDan Vatra <bogdan@kde.org> | 2019-04-02 14:00:37 +0300 |
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committer | BogDan Vatra <bogdan@kdab.com> | 2019-04-11 06:52:45 +0000 |
commit | 2c9fc2c1a197b84ba9ef3dc4e586a77a18c3dcc5 (patch) | |
tree | 38ac45eb44b585e47542c7b6df20088388836283 /src/plugins/sensors/android/sensoreventqueue.h | |
parent | f528104474dd74e34ea6a01da096e7c31730c01a (diff) |
Say hello to Qt Android Sensors based on NDK API
Until Qt 5.9, we had to use JNI way because the NDK sensors API was
introduced in API-16. Starting with Qt 5.9 we can safely use the NDK API
as API_16 is the minimum API supported by Qt.
Using the NDK API instead of JNI boost the performance a lot! The CPU
usage dropped 2 to 4 times, from over 60% using the JNI to less than
20%.
[ChangeLog][Android] Rewrite Qt Android Sensors using NDK
API.
Change-Id: If3e3f1e56973e2a189662912b2a6ebfbd71dee14
Reviewed-by: Lorn Potter <lorn.potter@gmail.com>
Diffstat (limited to 'src/plugins/sensors/android/sensoreventqueue.h')
-rw-r--r-- | src/plugins/sensors/android/sensoreventqueue.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/src/plugins/sensors/android/sensoreventqueue.h b/src/plugins/sensors/android/sensoreventqueue.h new file mode 100644 index 00000000..77bf05c6 --- /dev/null +++ b/src/plugins/sensors/android/sensoreventqueue.h @@ -0,0 +1,166 @@ +/**************************************************************************** +** +** Copyright (C) 2019 BogDan Vatra <bogdan@kde.org> +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtSensors module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef SENSOREVENTQUEUE_H +#define SENSOREVENTQUEUE_H + +#include "sensormanager.h" + +#include <functional> + +#include <QCoreApplication> +#include <QEvent> +#include <QSensorBackend> + +class FunctionEvent : public QEvent +{ +public: + using Function = std::function<void()>; + enum { + FunctionEventType = User + 1 + }; + explicit FunctionEvent(const Function &function) + : QEvent(Type(FunctionEventType)) + , m_function(function) + {} + + void callFunction() const + { + m_function(); + } +private: + Function m_function; +}; + +class ThreadSafeSensorBackend : public QSensorBackend +{ +public: + ThreadSafeSensorBackend(QSensor *sensor, QObject *parent = nullptr) + : QSensorBackend(sensor, parent) + , m_sensorManager(SensorManager::instance()) + {} + + // QObject interface + bool event(QEvent *event) override + { + if (event->type() == FunctionEvent::FunctionEventType) { + static_cast<FunctionEvent*>(event)->callFunction(); + event->accept(); + return true; + } + return QSensorBackend::event(event); + } +protected: + QSharedPointer<SensorManager> m_sensorManager; +}; + + + +template <typename T> +class SensorEventQueue : public ThreadSafeSensorBackend +{ +public: + explicit SensorEventQueue(int androidSensorType, QSensor *sensor, QObject *parent = nullptr) + : ThreadSafeSensorBackend(sensor, parent) + { + setReading<T>(&m_reader); + m_sensorEventQueue = ASensorManager_createEventQueue(m_sensorManager->manager(), m_sensorManager->looper(), -1, &looperCallback, this); + setSensorType(androidSensorType); + } + + ~SensorEventQueue() override + { + stop(); + ASensorManager_destroyEventQueue(m_sensorManager->manager(), m_sensorEventQueue); + } + + void setSensorType(int type) + { + bool started = m_started; + if (started) + stop(); + m_sensor = ASensorManager_getDefaultSensor(m_sensorManager->manager(), type); + setDescription(m_sensorManager->description(m_sensor)); + if (started) + start(); + } + + // QSensorBackend interface + void start() override + { + ASensorEventQueue_enableSensor(m_sensorEventQueue, m_sensor); + if (sensor()->dataRate() > 0) + ASensorEventQueue_setEventRate(m_sensorEventQueue, m_sensor, std::max(ASensor_getMinDelay(m_sensor), sensor()->dataRate())); + m_started = true; + } + void stop() override + { + ASensorEventQueue_disableSensor(m_sensorEventQueue, m_sensor); + m_started = false; + } + bool isFeatureSupported(QSensor::Feature feature) const override + { + switch (feature) { + case QSensor::SkipDuplicates: + return true; + default: + return false; + } + } + +protected: + virtual void dataReceived(const ASensorEvent &event) = 0; + static int looperCallback(int /*fd*/, int /*events*/, void* data) + { + ASensorEvent sensorEvent; + auto self = reinterpret_cast<SensorEventQueue*>(data); + while (ASensorEventQueue_getEvents(self->m_sensorEventQueue, &sensorEvent, 1)) + QCoreApplication::postEvent(self, new FunctionEvent{[=]{self->dataReceived(sensorEvent);}}); + + return 1; // 1 means keep receiving events + } + +protected: + T m_reader; + const ASensor *m_sensor = nullptr; + ASensorEventQueue* m_sensorEventQueue = nullptr; + bool m_started = false; +}; + +#endif // SENSOREVENTQUEUE_H |