起因
同事想要写一个代码，主进程中监听SIGINT、SIGTERM信号退出，并关闭启动的子进程，代码类似这样
import signal
import sys
import time
from multiprocessing import Process
from multiprocessing import Manager
class Test:
def __init__(self):
self.is_running = True
if sys.platform != 'win32':
signal.signal(signal.SIGHUP, self._signal_handler)
signal.signal(signal.SIGINT, self._signal_handler)
signal.signal(signal.SIGTERM, self._signal_handler)
def _signal_handler(self, signum, frame):
"""
Terminate scenario ticking when receiving a signal interrupt
"""
self.is_running = False
print('关闭场景调度')
def listen_manage(self, running, kill_task_lst):
"""监控取消任务"""
while running.value:
kill_task_lst.append(1)
time.sleep(1)
print("child is running")
def run(self):
"""启动场景调度"""
kill_task_lst = Manager().list()
running = Manager().Value(bool, True)
print('启动监控进程')
p = Process(target=self.listen_manage, args=(running, kill_task_lst, ))
p.start()
while self.is_running:
time.sleep(0.5)
print("main is running")
但是发现在ctrl + c 时候，子进程也同时接收到了信号，退出了
启动监控进程
main is running
main is running
child is running
main is running
关闭场景调度
Process Process-3:
Traceback (most recent call last):
File "D:\software\anaconda\envs\test_egg1\lib\multiprocessing\process.py", line 315, in _bootstrap
self.run()
File "D:\software\anaconda\envs\test_egg1\lib\multiprocessing\process.py", line 108, in run
self._target(*self._args, **self._kwargs)
File "D:\python_projects\pythonProject\test_egg\test.py", line 35, in listen_manage
time.sleep(1)
KeyboardInterrupt
main is running
这时猜想到可能是子进程也监听了SIGINT，退出了程序，所以想在子任务中设置忽略信号，改造后的 listen_manage：
def listen_manage(self, running, kill_task_lst):
"""监控取消任务"""
if sys.platform != 'win32':
signal.signal(signal.SIGHUP, signal.SIG_IGN)
signal.signal(signal.SIGINT, signal.SIG_IGN)
signal.signal(signal.SIGTERM, signal.SIG_IGN)
while running.value::
kill_task_lst.append(1)
time.sleep(1)
print("child is running")
运行后会报 BrokenPipeError: [WinError 232] 管道正在被关闭。
启动监控进程
main is running
main is running
child is running
main is running
关闭场景调度
main is running
child is running
Process Process-4:
Traceback (most recent call last):
File "D:\software\anaconda\envs\test_egg1\lib\multiprocessing\process.py", line 315, in _bootstrap
self.run()
File "D:\software\anaconda\envs\test_egg1\lib\multiprocessing\process.py", line 108, in run
self._target(*self._args, **self._kwargs)
File "D:\python_projects\pythonProject\test_egg\test.py", line 37, in listen_manage
kill_task_lst.append(1)
File "<string>", line 2, in append
File "D:\software\anaconda\envs\test_egg1\lib\multiprocessing\managers.py", line 834, in _callmethod
conn.send((self._id, methodname, args, kwds))
File "D:\software\anaconda\envs\test_egg1\lib\multiprocessing\connection.py", line 206, in send
self._send_bytes(_ForkingPickler.dumps(obj))
File "D:\software\anaconda\envs\test_egg1\lib\multiprocessing\connection.py", line 280, in _send_bytes
ov, err = _winapi.WriteFile(self._handle, buf, overlapped=True)
BrokenPipeError: [WinError 232] 管道正在被关闭。
这里想到的原因是父进程直接退出了，导致共享变量kill_task_lst被关闭导致的，所以想在关闭管道前等待子进程退出
可执行的完整代码:
import signal
import sys
import time
from multiprocessing import Process
from multiprocessing import Manager
class Test:
def __init__(self):
self.is_running = True
if sys.platform != 'win32':
signal.signal(signal.SIGHUP, self._signal_handler)
signal.signal(signal.SIGINT, self._signal_handler)
signal.signal(signal.SIGTERM, self._signal_handler)
def _signal_handler(self, signum, frame):
"""
Terminate scenario ticking when receiving a signal interrupt
"""
self.is_running = False
print('关闭场景调度')
def listen_manage(self, running, kill_task_lst):
"""监控取消任务"""
if sys.platform != 'win32':
signal.signal(signal.SIGHUP, signal.SIG_IGN)
signal.signal(signal.SIGINT, signal.SIG_IGN)
signal.signal(signal.SIGTERM, signal.SIG_IGN)
while running.value:
kill_task_lst.append(1)
time.sleep(1)
print("child is running")
def run(self):
"""启动场景调度"""
kill_task_lst = Manager().list()
running = Manager().Value(bool, True)
print('启动监控进程')
p = Process(target=self.listen_manage, args=(running, kill_task_lst, ))
p.start()
while self.is_running:
time.sleep(0.5)
print("main is running")
running.set(False)
while p.is_alive():
time.sleep(0.01)
print("finish.....")
if __name__ == '__main__':
t = Test()
t.run()
执行结果:
启动监控进程
main is running
main is running
child is running
main is running
关闭场景调度
main is running
child is running
finish.....
