QThread Freezes GUI

[GLaDOS1105]

It is not completely freezing. However, when I do some heavy tasks in QThread, the GUI responds slowly. For instance,

import sys
from PySide2.QtCore import QThread
from PySide2.QtWidgets import (QApplication, QWidget, PushButton,QComboBox, QVBoxLayout)

class Task(QThread):
    def run(self):
        # some heavy tasks
        print('task started')
        k = 0
        for i in range(10000):
            for j in range(50000):
                k += 1
        print('task finished')

class Gui(QWidget):
    def __init__(self):
        super().__init__()
        layout = QVBoxLayout()
        button = QPushButton('click me')
        button.clicked.connect(self.do_task)
        combobox = QComboBox()
        combobox.addItems(['1', '2', '3', '4', '5'])
        layout.addWidget(button)
        layout.addWidget(combobox)
        self.setLayout(layout)

    def do_task(self):
        self.thread = Task()
        self.thread.start()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = Gui()
    window.show()
    sys.exit(app.exec_())

Here is the example GIF animation.

However, if I use PyQt5 to run the script (replacing PySide2 module), the GUI response will not delay at all.

How could I make the GUI have more CPU resource or higher priority when there are other threads running at the same time?

Testing environment: Python 3.6, PySide2 5.11.1, PyQt5 5.11.2, Kubuntu 18.04 64-bit.

[SGaist]

Hi,

Looks like there's some problem with the PySide 2 implementation. You should check the bug report system to see if it's something known. If not, please consider opening a new report providing your example and as much details as possible about your current setup.