GUI is Freeze When Start QtConcurrent::run Process

[Ketan__Patel__0011]

Hello Qt Experts And my friends

Currently i am facing GUI freezing problem in my project

My Application GUI is Freeze when i start multiple QtConcurrent::run process

for example i want to run 2 or 3 methods parallelly
or in this methods i am doing some looping code thigs or some processing or etc then when i Try To Display result in my GUI Controls like QLabel Or QFrame or etc.. that time my GUI Is freezed But Backend processing is running

My All Background processing Is Work Correctly like QTimer Value But GUI is freezed

And Other things is when i Clicked on my other Controls like QPushButton that time My Application is Keep going Normally with All GUI Controls

Please Help me for find out the solution Or If You have Solution or Any idea About My Problem then Please Drop Your idea or solution here....

Thank You So Much

[SGaist]

Hi,

Please show the code where you are using QtCouncurrent.

If something freezes, you have likely used a method to wait on the result of your computation.

[Ketan__Patel__0011]

@SGaist

Thanks For Reply

void MainWindow::StartFunctions()
{
    if(!future_1.isRunning())
        future_1 = QtConcurrent::run(&pool, this, &MainWindow::Function_1); 
    if(!future_2 .isRunning())
        future_2 = QtConcurrent::run(&pool, this, &MainWindow::Function_2); 
}

void MainWindow::Function_1()
{
        while(IS_Thread_1_Start == true)
        {
                 ///// My Code
        }
}

void MainWindow::Function_2()
{
        while(IS_Thread_2_Start == true)
        {
                 ///// My Code
        }
}

void MainWindow::on_BtnStart_clicked() //// START
{
     StartFunctions();
}

void MainWindow::on_BtnStop_clicked() //// STOP
{
     IS_Thread_1_Start = false;
     IS_Thread_2_Start = false;
}

[SGaist]

Why are you implementing such blocking loops within your MainWindow code ?

[Ketan__Patel__0011]

@SGaist

Thanks For Reply

because I want to call my MainWindow Class functions in my Threads Functions

Like this::

void MainWindow::Function_1_Process()
{
         ui->Label_1->setText(QString::number(Number_1)) /// Here Number_1 Is My Windows Class Member
}

void MainWindow::Function_2_Process()
{
         ui->Label_2->setText(QString::number(Number_2)) /// Here Number_2 Is My Windows Class Member
}


void MainWindow::Function_1()
{
        while(IS_Thread_1_Start == true)
        {
              Function_1_Process();
              Number_1 += 1;
        }
}

void MainWindow::Function_2()
{
        while(IS_Thread_2_Start == true)
        {
                 Function_2_Process();
                 Number_1 += 1;
        }
}

[jsulm]

@Ketan__Patel__0011 said in GUI is Freeze When Start QtConcurrent::run Process:

because I want to call my MainWindow Class functions in my Threads Functions

Never do this directly! Only GUI thread is allowed to change the UI (access UI related objects)!
Emit a signal from the other thread and connect that signal to a slot in MainWindow.

[Ketan__Patel__0011]

@jsulm
Thanks For Reply

I Understand
but now is there any other way to help for this problem ?

[jsulm]

@Ketan__Patel__0011 What is wrong with my suggestion?
You could also use https://doc.qt.io/qt-5/qmetaobject.html#invokeMethod with Qt::QueuedConnection

[Ketan__Patel__0011]

@jsulm

Your Suggestion Is Not Wrong

[jsulm]

This post is deleted!

[jsulm]

@Ketan__Patel__0011 OK. Then take a look at the alternative I proposed.