Qtconcurrent finish signal ...

gfxx

I would like to get the finisched signal from my qtconcurrent <void> to use it in a signal slot mechanism ... i need to use qtfuturewatcher and qtfuture? .... my void read some file on lan and charge the file name on Qlist .... when the operation is finish I need to have finish signal because I have a lot of these type of operation (10) so i can update my progress bar every action was finisch ..... or reuse the same void for reading file to other folder ....

regards
giorgio

jsulm

@gfxx You should really use correct wording: "qtconcurrent <void>" - do you mean QtConcurrent::run? "or reuse the same void" - use same void, what does it mean?
So, do you use QtConcurrent::run? If so, then yes you need to use QFuture and QFutureWatcher.

gfxx

@jsulm Thanks ... real sorry for bad written worlds .... I promise that in the coming months I will start an English course .... because I'm tired of seeing my words are not well written.

Anyway thanks a lot.
giorgio

jsulm

@gfxx Its not about your English, it is more about the correct terms. For example: it is QtConcurrent::run, not QtConcurrent<void>. The problem with wrong terms is that it can be hard to understand what is actually meant.

gfxx

@jsulm .... I think I use these structure of code:

#include <QCoreApplication>
#include <qtconcurrentrun.h>
#include <QThread>

#ifndef QT_NO_CONCURRENT

void myRunFunction(QString name)
{
    for(int i = 0; i <= 5; i++)
    {
        qDebug() << name << " " << i <<
                    "from" << QThread::currentThread();
    }
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QFuture<void> t1 = QtConcurrent::run(myRunFunction, QString("A"));
    QFuture<void> t2 = QtConcurrent::run(myRunFunction, QString("B"));
    QFuture<void> t3 = QtConcurrent::run(myRunFunction, QString("C"));

    t1.waitForFinished();
    t2.waitForFinished();
    t3.waitForFinished();

    return a.exec();
}

#else

#include <QLabel>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QString text("Qt Concurrent is not yet supported on this platform");

    QLabel *label = new QLabel(text);
    label->setWordWrap(true);

    label->show();
    qDebug() << text;

    app.exec();
}
#endif

in these case QFuture<void> t1 = QtConcurrent::run(myRunFunction, QString("A")); I think to use these row of code. So I better re-write my question:

For bring "isfinished SIGNAL" in these case I must use QFutureWatcher?

You are in right ... my terminology is wrong .... I had to say QFuture <void> and not Qconcurrent <void> .... or say to use a Void with Qcouncurrent and get an isfinished signal ...

So my terminology is bad as my english :)) .... So I do not think it's such a bad thing to spend my money on an English course.

Have a Happy day ... and Thanks a lot.

Giorgio

J.Hilk

@gfxx If I'm not totally wrong, than you can simply emit a Signal at the end of your run funtion!

void myRunFunction(QString name)
{
    for(int i = 0; i <= 5; i++)
    {
        qDebug() << name << " " << i <<
                    "from" << QThread::currentThread();
    }
    emit runIsDone();
}

Just connect that Signal to a Slot and go from there. To be sure give the Connect a Qt::QueuedConnection as 5th parameter.

gfxx

@J.Hilk said in Qtconcurrent finish signal ...:

f I'm not totally wrong, than you can simply emit a Signal at the end of your run funtion!

you are in right ... these is my ideas too .... an in the afternoon I try .... but I would know if there are some other SIGNAL type already ready, without make a new one .....

regards
giorgio

Asperamanca

Structure is more or less like this:

   QFuture<MyClass> future = QtConcurrent::run(function,..);
   QFutureWatcher<MyClass>* pWatcher = new QFutureWatcher(parent);
   pWatcher->setFuture(future);
   // Now I can use signals emitted by pWatcher

gfxx

@Asperamanca thanks.