在 Windows 上优雅地终止子 Python 进程，以便运行 finally 子句 [英] Gracefully Terminate Child Python Process On Windows so Finally clauses run

问题描述

在 Windows 机器上，我有许多场景，其中父进程将启动子进程.出于各种原因 - 父进程可能想要中止子进程，但是(这很重要)允许它清理 - 即运行 finally 子句:

On Windows boxes, I have a number of scenarios where a parent process will start a child process. For various reasons - the parent process may want to abort the child process but (and this is important) allow it to clean up - ie run a finally clause:

try:
  res = bookResource()
  doStuff(res)
finally:
  cleanupResource(res)

(这些东西可能嵌入在更接近的上下文中 - 通常围绕硬件锁定/数据库状态)

(These things may be embedded in contexts like the closer - and generally are around hardware locking/database state)

问题是我无法找到在 Windows 中向孩子发出信号的方法(就像在 Linux 环境中一样)，因此它会在终止之前运行清理.我认为这需要让子进程以某种方式引发异常(就像 Ctrl-C 那样).

The problem is that I'm unable to find a way to signal the child in Windows (as I would in a Linux environment) so it would run the clean up before terminating. I think this requires making the child process raise an exception somehow (as the Ctrl-C would).

我尝试过的事情:

• os.kill
• 操作系统信号
• subprocess.Popen 与 creationFlags 并使用 ctypes.windll.kernel32.GenerateConsoleCtrlEvent(1, p.pid) abrt 信号.这需要一个信号陷阱和不优雅的循环来阻止它立即中止.
• ctypes.windll.kernel32.GenerateConsoleCtrlEvent(0, p.pid)- ctrl-c 事件 - 什么也没做.

• os.kill
• os.signal
• subprocess.Popen with creationFlags and using ctypes.windll.kernel32.GenerateConsoleCtrlEvent(1, p.pid) abrt signal. This requires a signal trap and inelegant loop to stop it immediately aborting.
• ctypes.windll.kernel32.GenerateConsoleCtrlEvent(0, p.pid)- ctrl-c event - did nothing.

有没有人有办法做到这一点，以便子进程可以清理?

Has anyone got a surefire way of doing this, so that the child process can clean up?

推荐答案

我能够让 GenerateConsoleCtrlEvent 像这样工作:

I was able to get the GenerateConsoleCtrlEvent working like this:

import time
import win32api
import win32con
from multiprocessing import Process


def foo():
    try:
        while True:
            print("Child process still working...")
            time.sleep(1)
    except KeyboardInterrupt:
        print "Child process: caught ctrl-c"

if __name__ == "__main__":
    p = Process(target=foo)
    p.start()
    time.sleep(2)

    print "sending ctrl c..."
    try:
        win32api.GenerateConsoleCtrlEvent(win32con.CTRL_C_EVENT, 0)
        while p.is_alive():
            print("Child process is still alive.")
            time.sleep(1)
    except KeyboardInterrupt:
        print "Main process: caught ctrl-c"

输出

Child process still working...
Child process still working...
sending ctrl c...
Child process is still alive.
Child process: caught ctrl-c
Main process: caught ctrl-c

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