在pyqt5 /Python3中，当主GUI窗口关闭时，如何使子线程关闭？

from PyQt5.QtCore import QThread

class MyThread(QThread):
    def run(self):
        # 子线程的逻辑代码
        pass

from PyQt5.QtWidgets import QMainWindow

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.thread = MyThread()

    def start_thread(self):
        self.thread.start()

from PyQt5.QtWidgets import QApplication, QMainWindow

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.thread = MyThread()

    def start_thread(self):
        self.thread.start()

    def closeEvent(self, event):
        self.thread.quit()
        self.thread.wait()
        event.accept()