我有一个创建QRunnable并将其在QThreadPool实例中启动的类。
我的线程运行良好，但是如果用户想要退出应用程序，则该应用程序需要花费很长时间才能停止。当然，由于发出请求需要时间。
这是我如何使用QThreadPool QRunnables的代码段代码：
import sys
from PyQt5.Qt import QThreadPool, QApplication, QWidget, QVBoxLayout
from PyQt5.Qt import QTimer, QObject, QPushButton, QLabel
from PyQt5.Qt import QRunnable
class BackendQRunnable(QRunnable):
"""
Class who create a QThread to trigger requests
"""
def __init__(self, task):
super(BackendQRunnable, self).__init__()
self.task = task
def run(self):
"""
Run the QRunnable. Trigger actions depending on the selected task
"""
# Here I make long requests
if 'user' in self.task:
self.query_user_data()
elif 'host' in self.task:
self.query_hosts_data()
elif 'service' in self.task:
self.query_services_data()
elif 'alignakdaemon' in self.task:
self.query_daemons_data()
elif 'livesynthesis' in self.task:
self.query_livesynthesis_data()
elif 'history' in self.task:
self.query_history_data()
elif 'notifications' in self.task:
self.query_notifications_data()
else:
pass
@staticmethod
def query_user_data():
"""
Launch request for "user" endpoint
"""
print('Query user data')
@staticmethod
def query_hosts_data():
"""
Launch request for "host" endpoint
"""
print('Query hosts')
@staticmethod
def query_services_data():
"""
Launch request for "service" endpoint
"""
print("Query services")
@staticmethod
def query_daemons_data():
"""
Launch request for "alignakdaemon" endpoint
"""
print('Query daemons')
@staticmethod
def query_livesynthesis_data():
"""
Launch request for "livesynthesis" endpoint
"""
print('query livesynthesis')
@staticmethod
def query_history_data():
"""
Launch request for "history" endpoint but only for hosts in "data_manager"
"""
print('Query history')
@staticmethod
def query_notifications_data():
"""
Launch request for "history" endpoint but only for notifications of current user
"""
print('Query notifications')
class ThreadManager(QObject):
"""
Class who create BackendQRunnable to periodically request on a Backend
"""
def __init__(self, parent=None):
super(ThreadManager, self).__init__(parent)
self.backend_thread = BackendQRunnable(self)
self.pool = QThreadPool.globalInstance()
self.tasks = self.get_tasks()
def start(self):
"""
Start ThreadManager
"""
print("Start backend Manager...")
# Make a first request
self.create_tasks()
# Then request periodically
timer = QTimer(self)
timer.setInterval(10000)
timer.start()
timer.timeout.connect(self.create_tasks)
@staticmethod
def get_tasks():
"""
Return the tasks to run in BackendQRunnable
:return: tasks to run
:rtype: list
"""
return [
'notifications', 'livesynthesis', 'alignakdaemon', 'history', 'service', 'host', 'user',
]
def create_tasks(self):
"""
Create tasks to run
"""
for cur_task in self.tasks:
backend_thread = BackendQRunnable(cur_task)
# Add task to QThreadPool
self.pool.start(backend_thread)
def exit_pool(self):
"""
Exit all BackendQRunnables and delete QThreadPool
"""
# When trying to quit, the application takes a long time to stop
self.pool.globalInstance().waitForDone()
self.pool.deleteLater()
sys.exit(0)
if __name__ == '__main__':
app = QApplication(sys.argv)
thread_manager = ThreadManager()
thread_manager.start()
layout = QVBoxLayout()
label = QLabel("Start")
button = QPushButton("DANGER!")
button.pressed.connect(thread_manager.exit_pool)
layout.addWidget(label)
layout.addWidget(button)
w = QWidget()
w.setLayout(layout)
w.show()
sys.exit(app.exec_())
在功能
exit_pool中，我等到线程完成并删除QThreadPool实例...有没有一种方法可以不等待每个线程并直接停止所有线程？
编辑解决方案：
所以我对这个问题的看法不同。我用
QRunnable替换了QThread。我删除了QThreadPool，并在列表中管理线程。我还添加了pyqtSignal以停止QTimer并通过quit()函数关闭正在运行的线程。这样我所有的线程都退出了，没有问题。
import sys
from PyQt5.Qt import QThread, QApplication, QWidget, QVBoxLayout
from PyQt5.Qt import QTimer, QObject, QPushButton, QLabel, pyqtSignal
class BackendQThread(QThread):
"""
Class who create a QThread to trigger requests
"""
quit_thread = pyqtSignal(name='close_thread')
def __init__(self, task):
super(BackendQThread, self).__init__()
self.task = task
def run(self):
"""
Run the actions depending on the selected task
"""
# Here I make long requests
if 'user' in self.task:
self.query_user_data()
elif 'host' in self.task:
self.query_hosts_data()
elif 'service' in self.task:
self.query_services_data()
elif 'alignakdaemon' in self.task:
self.query_daemons_data()
elif 'livesynthesis' in self.task:
self.query_livesynthesis_data()
elif 'history' in self.task:
self.query_history_data()
elif 'notifications' in self.task:
self.query_notifications_data()
else:
pass
@staticmethod
def query_user_data():
"""
Launch request for "user" endpoint
"""
print('Query user data')
@staticmethod
def query_hosts_data():
"""
Launch request for "host" endpoint
"""
print('Query hosts')
@staticmethod
def query_services_data():
"""
Launch request for "service" endpoint
"""
print("Query services")
@staticmethod
def query_daemons_data():
"""
Launch request for "alignakdaemon" endpoint
"""
print('Query daemons')
@staticmethod
def query_livesynthesis_data():
"""
Launch request for "livesynthesis" endpoint
"""
print('query livesynthesis')
@staticmethod
def query_history_data():
"""
Launch request for "history" endpoint but only for hosts in "data_manager"
"""
print('Query history')
@staticmethod
def query_notifications_data():
"""
Launch request for "history" endpoint but only for notifications of current user
"""
print('Query notifications')
class ThreadManager(QObject):
"""
Class who create BackendQThread to periodically request on a Backend
"""
def __init__(self, parent=None):
super(ThreadManager, self).__init__(parent)
self.tasks = self.get_tasks()
self.timer = QTimer()
self.threads = []
def start(self):
"""
Start ThreadManager
"""
print("Start backend Manager...")
# Make a first request
self.create_tasks()
# Then request periodically
self.timer.setInterval(10000)
self.timer.start()
self.timer.timeout.connect(self.create_tasks)
@staticmethod
def get_tasks():
"""
Return the available tasks to run
:return: tasks to run
:rtype: list
"""
return [
'notifications', 'livesynthesis', 'alignakdaemon', 'history', 'service', 'host', 'user',
]
def create_tasks(self):
"""
Create tasks to run
"""
# Here I reset the list of threads
self.threads = []
for cur_task in self.tasks:
backend_thread = BackendQThread(cur_task)
# Add task to QThreadPool
backend_thread.start()
self.threads.append(backend_thread)
def stop(self):
"""
Stop the manager and close all QThreads
"""
print("Stop tasks")
self.timer.stop()
for task in self.threads:
task.quit_thread.emit()
print("Tasks finished")
if __name__ == '__main__':
app = QApplication(sys.argv)
layout = QVBoxLayout()
widget = QWidget()
widget.setLayout(layout)
thread_manager = ThreadManager()
start_btn = QPushButton("Start")
start_btn.clicked.connect(thread_manager.start)
layout.addWidget(start_btn)
stop_btn = QPushButton("Stop")
stop_btn.clicked.connect(thread_manager.stop)
layout.addWidget(stop_btn)
widget.show()
sys.exit(app.exec_())
最佳答案
QRunnable启动后就无法停止。但是，您可以通过一些简单的操作来减少示例中的等待时间。
首先，您可以停止计时器，这样它就不会添加任何其他任务。其次，您可以clear the thread-pool以便删除所有未完成的任务。第三，您可以尝试setting a smaller maximum thread count来查看它是否仍然达到可接受的性能。默认情况下，线程池将使用QThread.idealThreadCount()设置最大线程数-这通常意味着系统上的每个处理器核心一个线程。
最后一种选择是提供一种中断在可运行对象中执行的代码的方法。这只有在代码运行一个循环时才能真正实现，该循环可以定期检查标志以查看其是否应该继续。在您的示例中，由于所有任务都调用静态方法，因此您似乎可以将单个共享类属性用于该标志。但是，如果代码不能以这种方式被中断，则您无能为力-您只需要等待当前正在运行的任务完成即可。