Python multiprocessing return value and timeout example

mp.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Python multiprocessing return value and timeout example
"""

from __future__ import print_function
import argparse
import sys
import multiprocessing
from ctypes import c_char_p
from time import sleep
import random

PROC_COUNT = 5
SLEEP_MAX = 10
TERMINATE_THRESHOLD = 5


def proc_func(shared_val):
    sleep_time = random.randint(1, SLEEP_MAX)
    print('started ({})'.format(sleep_time))
    sleep(sleep_time)
    print('finished')
    shared_val['job_command'] = 'sleep {}'.format(sleep_time)


def do_mp():
    val_list = []
    proc_list = []
    with multiprocessing.Manager() as manager:
        for proc_num in range(PROC_COUNT):
            print('creating {}'.format(proc_num))
            val = manager.dict()
            val_list.append(val)
            proc = multiprocessing.Process(target = proc_func, name = 'proc{}'.format(proc_num), args = (val,))
            proc_list.append(proc)
            proc.start()

        join_count = 0
        finished_list = []
        while len(finished_list) != len(proc_list):
            for proc in proc_list:
                if proc.name not in finished_list:
                    proc.join(0.001)
                    if proc.is_alive() and join_count >= TERMINATE_THRESHOLD:
                        proc.terminate()
                        print('terminated {}'.format(proc.name))

                        finished_list.append(proc.name)

                    if not proc.is_alive():
                        print('joined {}'.format(proc.name))

                        finished_list.append(proc.name)

            sleep(1)
            join_count += 1

        for idx, proc in enumerate(proc_list):
            print('{}: {}'.format(idx, val_list[idx]))


def run():
    try:
        do_mp()

    except Exception as e:
        print('Error: ({}) {}'.format(e.__class__.__name__, e), file = sys.stderr)
        sys.exit(1)

    except KeyboardInterrupt:
        pass


if __name__ == "__main__":
    run()