QSignal in thread work for hight cpu

[Nguyen Don]

Hi all,
I have issue when draw chart in thread after a period of time then cpu up to 100% performent
can anyone help me?
Thanks,
qml file

import QtQuick 2.7
import QtQuick.Window 2.2
import QtQuick.Controls 2.0
import QtCharts 2.0

ApplicationWindow {
    visible: true
    width: 600
    height: 300
    property int timeStep: 0

    ChartView {
        id: chartView
        anchors.fill: parent

        ValueAxis {
            id: axisX
            min: 0
            max: 400

        }

        Component.onCompleted:  {
            mapper.series = series2
        }

        LineSeries {
            id: series2
            axisX: axisX
            name: "From C++"
            color: "red"
            width: 5
        }
    }
}

main.cpp

#include <QApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include <thread>
#include <QtCharts/QVXYModelMapper>
#include "mydatamodel.h"
#include <QtMath>

void point_generator_proc(MyDataModel* model)
{
    for(double t=0 ; ; t+=1)
    {
        double y = (1 + sin(t/10.0)) / 2.0;
        model->handleNewPoint(QPointF(t, y));
        std::this_thread::sleep_for(std::chrono::milliseconds(50));
    }
}


int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QQmlApplicationEngine engine;
    auto context = engine.rootContext();

    auto myDataModel = new MyDataModel();

    auto mapper = new QtCharts::QVXYModelMapper();
    mapper->setModel(myDataModel);
    mapper->setXColumn(0);
    mapper->setYColumn(1);

    std::thread point_generator_thread(point_generator_proc, myDataModel);


    context->setContextProperty("mapper", mapper);
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));


    app.exec();
    point_generator_thread.join();
     return 0;
}

mydatamodel.cpp

#include "mydatamodel.h"
#include <QtMath>
#include <QDebug>
MyDataModel::MyDataModel()
{
    QObject::connect(this, &MyDataModel::newPointAdded, this, &MyDataModel::addNewPoint,
                     Qt::QueuedConnection);
}


void MyDataModel::handleNewPoint(const QPointF &point)
{
    emit newPointAdded(point);
}

void MyDataModel::addNewPoint(const QPointF& point)
{
    beginInsertRows(QModelIndex(), rowCount(), rowCount());
    m_data.push_back(point);
    endInsertRows();
}


int MyDataModel::rowCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent)
    return m_data.size();
}

int MyDataModel::columnCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent)
    return 2;
}

QVariant MyDataModel::headerData(int section, Qt::Orientation orientation, int role) const
{
    Q_UNUSED(orientation)
    Q_UNUSED(role)

    if(section == 0)
        return "x";
    else
        return "y";
}

QVariant MyDataModel::data(const QModelIndex &index, int role) const
{
    Q_UNUSED(role)

    if (index.column() == 0)
        return m_data[index.row()].x();
    else
        return m_data[index.row()].y();
}

mydatamodel.h

#include <QAbstractTableModel>
#include <QPointF>
#include <vector>
#include <QThread>

class MyDataModel : public QAbstractTableModel
{
    Q_OBJECT
public:
    void handleNewPoint(const QPointF& point);
signals:
    void newPointAdded(const QPointF& point);
public:
    MyDataModel();
    int rowCount(const QModelIndex &parent = QModelIndex()) const;
    int columnCount(const QModelIndex &parent = QModelIndex()) const;
    QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const;
    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;

private:
    void addNewPoint(const QPointF& point);
    std::vector<QPointF> m_data;
};