multiexit 1.3.0

atexit replacement that supports multiprocessing

A better, saner and more useful atexit replacement for Python 3 that supports multiprocessing.

Inspired by the following StackOverflow question and experience on building multiprocess daemons:

https://stackoverflow.com/q/2546276

multiexit will install a handler for the SIGTERM signal and execute the registered exit functions in LIFO order (Last In First Out). multiexit will only execute exit functions that are owned by the process shutting down.

Install

multiexit is available for Python 3 from PyPI.

pip3 install multiexit

Usage

from time import sleep
from signal import SIGTERM
from os import kill, getpid
from multiprocessing import Process

from multiexit import install, register, unregister


if __name__ == '__main__':

    # Always call install() on the main process before creating any
    # subprocess
    #
    # This will install a required handler for SIGTERM. Subprocesses must
    # inherit this handler. Plus it assigns a pid as the master process
    # for exit or os._exit call.
    install()

    def _subproc1():

        @register
        def subproc1_clean():
            print('Subprocess clean!')

        sleep(1000)

    subproc1 = Process(
        name='SubProcess1',
        target=_subproc1,
    )
    # proc.daemon = True
    # daemon means that signals (like SIGTERM) will be propagated automatically
    # to children. Set to false (the default), to handle the SIGTERM
    # (process.terminate()) to the children yourself.
    subproc1.start()

    # Register a cleaner using a decorator
    @register
    def clean_main():
        print('Terminating child {}'.format(
            subproc1.pid,
        ))
        subproc1.terminate()
        subproc1.join()
        print('Child {} ended with {}'.format(
            subproc1.pid,
            subproc1.exitcode,
        ))

    # Wait, and then kill main process
    sleep(3)

    # Suicide
    kill(getpid(), SIGTERM)

For a more extensive example check out example.py.

License

Copyright (C) 2018 KuraLabs S.R.L

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.