Qt5 / C++ - Time delay, Windows 10 - Windows 7

[jimbo]

QT 5.6.0

Hello,

I'm using a time delay in my program, and noticed a drastic difference
in execution time between Windows 10 and Windows 7 (Dual boot system).
The time delay does not have to accurate (Animation).

Typical output:-
15156535 Windows 10
1379155 Windows 7

Its probably the processEvents, I would like the system to be responsive.
Is there a better way to achive similar results between the two systems?

Regards

void myProg:tDelay(int milliSecs)
{
    QElapsedTimer timer;
    timer.restart();
    qint64 nanoSec;
    timer.start();
 
    QTime dieTime = QTime::currentTime().addMSecs(milliSecs);
    while (QTime::currentTime() < dieTime)
        QCoreApplication::processEvents(QEventLoop::AllEvents, 1);
 
    nanoSec = timer.nsecsElapsed();
    qDebug() << nanoSec;
}

void myProg:tDelay(int milliSecs)
{
    QElapsedTimer timer;
    timer.restart();
    qint64 nanoSec;
    timer.start();

    QTime dieTime = QTime::currentTime().addMSecs(milliSecs);
    while (QTime::currentTime() < dieTime)
        QCoreApplication::processEvents(QEventLoop::AllEvents, 1);

    nanoSec = timer.nsecsElapsed();
    qDebug() << nanoSec;
}

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[anda_skoa]

QTime::currentTime can be a very costly call.

But maybe you can explain what you are actually trying to do?
That doesn't look like anything that would appear in a real program.

Cheers,
_

[jimbo]

Hello anda_skoa,

Thanks for your reply.
I'm doing nothing more than moving a QLabel around a form, with the delay between moves.

Regards

[anda_skoa]

Hmm.

Wouldn't that be easier with a QPropertyAnimation?

Cheers,
_

[Lesiok]

If You really need this method do it like this :

void myProg:tDelay(int milliSecs)
{
    QElapsedTimer timer;
    timer.restart();
    qint64 nanoSec;
    timer.start();
    QEventLoop loop;
    QTimer::singleShot( milliSecs,&loop,SLOT(quit()) );
    loop.exec();
 
    nanoSec = timer.nsecsElapsed();
    qDebug() << nanoSec;
}

void myProg:tDelay(int milliSecs)
{
    QElapsedTimer timer;
    timer.restart();
    qint64 nanoSec;
    timer.start();
    QEventLoop loop;
    QTimer::singleShot( milliSecs,&loop,SLOT(quit()) );
    loop.exec();

    nanoSec = timer.nsecsElapsed();
    qDebug() << nanoSec;
}

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[jimbo]

Helo,

Thanks to anda_skoa and Lesiok.

Wouldn't that be easier with a QPropertyAnimation?

Yes, some nice effects.

If You really need this method do it like this :

Gives a simiar result between the two systems.

Regards