Python 进程不会调用 atexit
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Python Process won't call atexit
提问by Brian M. Hunt
I'm trying to use atexitin a Process, but unfortunately it doesn't seem to work. Here's some example code:
我正在尝试atexit在 a 中使用Process，但不幸的是它似乎不起作用。下面是一些示例代码：
import time
import atexit
import logging
import multiprocessing
logging.basicConfig(level=logging.DEBUG)
class W(multiprocessing.Process):
def run(self):
logging.debug("%s Started" % self.name)
@atexit.register
def log_terminate():
# ever called?
logging.debug("%s Terminated!" % self.name)
while True:
time.sleep(10)
@atexit.register
def log_exit():
logging.debug("Main process terminated")
logging.debug("Main process started")
a = W()
b = W()
a.start()
b.start()
time.sleep(1)
a.terminate()
b.terminate()
The output of this code is:
这段代码的输出是：
DEBUG:root:Main process started DEBUG:root:W-1 Started DEBUG:root:W-2 Started DEBUG:root:Main process terminated
I would expect that the W.run.log_terminate()would be called when a.terminate()and b.terminate()are called, and the output to be something likeso (emphasis added)!:
我希望W.run.log_terminate()在调用a.terminate()和调用时b.terminate()调用 ，并且输出是这样的（强调添加）！：
DEBUG:root:Main process started DEBUG:root:W-1 Started DEBUG:root:W-2 Started DEBUG:root:W-1 Terminated! DEBUG:root:W-2 Terminated! DEBUG:root:Main process terminated
Why isn't this working, and is there a better way to log a message (from the Processcontext) when a Processis terminated?
为什么这不起作用，Process当 aProcess终止时，是否有更好的方法来记录消息（来自上下文）？
Thank you for your input - it's much appreciated.
感谢您的投入 - 非常感谢。
Solution
解决方案
EDIT: Based on solution suggested by Alex Martelli, the following works as expected:
编辑：基于 Alex Martelli 建议的解决方案，以下按预期工作：
import sys
import time
import atexit
import signal
import logging
import multiprocessing
logging.basicConfig(level=logging.DEBUG)
class W(multiprocessing.Process):
def run(self):
logging.debug("%s Started" % self.name)
def log_terminate(num, frame):
logging.debug("%s Terminated" % self.name)
sys.exit()
signal.signal(signal.SIGTERM, log_terminate)
while True:
time.sleep(10)
@atexit.register
def log_exit():
logging.debug("Main process terminated")
logging.debug("Main process started")
a = W()
b = W()
a.start()
b.start()
time.sleep(1)
a.terminate()
b.terminate()
It's worthwhile to note the following comment in the atexitdocumentation:
值得在atexit文档中注意以下注释：
Note: the functions registered via this module are not called when the program is killed by a signal, when a Python fatal internal error is detected, or when os._exit() is called.
注意：当程序被信号杀死、检测到 Python 致命内部错误或调用 os._exit() 时，不会调用通过该模块注册的函数。
采纳答案by Alex Martelli
As the docssay,
正如文档所说，
On Unix this is done using the SIGTERM signal; on Windows TerminateProcess() is used. Note that exit handlers and finally clauses, etc., will not be executed.
在 Unix 上，这是使用 SIGTERM 信号完成的；在 Windows 上使用 TerminateProcess()。请注意，不会执行退出处理程序和 finally 子句等。
If you're on Unix, you should be able intercept SIGTERMwith signal, and perform whatever "termination activities" you need; however, I don't know of a cross-platform solution.
如果您在 Unix 上，您应该能够SIGTERM使用信号进行拦截，并执行您需要的任何“终止活动”；但是，我不知道跨平台解决方案。
