Killing parent process from a child process with Python on Linux

Question

In my (very simplified) scenario, in python 2.7, I have 2 processes:

1. Parent process, which doing some tasks.
2. Child process, which needs to kill the parent process after X time.

Creation of child process:

killer = multiprocessing.Process(...)
killer.start()

The child process executes the following code after X time (simplified version of the code):

process = psutil.Process(parent_pid)
...
if time_elapsed:
    while True:
        process.kill()
        if not process.is_alive:
            exit()

The problem is that it's leaving the parent as a zombie process, and the child is never exiting because the parent is still alive.

The same code works as expected in Windows.

All the solutions that I saw were talking about the parent process waiting for the child to finish by calling killer.join(), but in my case, the parent is the one who does the task, and it shouldn't wait for its child.

What is the best way to deal with a scenario like that?

Answer 1

You could use os.getppid() to retrieve the parent's PID, and kill it with os.kill().

E.g. os.kill(os.getppid(), signal.SIGKILL)

See https://docs.python.org/2/library/os.html and https://docs.python.org/2/library/signal.html#module-signal for reference.

A mwo:

Parent:

import subprocess32 as subprocess

subprocess.run(['python', 'ch.py'])

Child:

import os
import signal

os.kill(os.getppid(), signal.SIGTERM)