#!/usr/bin/env python
# -*- coding: UTF-8 -*-
import multiprocessing
# We must import this explicitly, it is not imported by the top-level
# multiprocessing module.
import multiprocessing.pool
import time
from random import randint
[docs]class NoDaemonProcess(multiprocessing.Process):
# make 'daemon' attribute always return False
def _get_daemon(self):
return False
def _set_daemon(self, value):
pass
daemon = property(_get_daemon, _set_daemon)
# We sub-class multiprocessing.pool.Pool instead of multiprocessing.Pool
# because the latter is only a wrapper function, not a proper class.
[docs]class MyPool(multiprocessing.pool.Pool):
Process = NoDaemonProcess
[docs]def sleepawhile(t):
print(("Sleeping %i seconds..." % t))
time.sleep(t)
return t
[docs]def work(num_procs):
print(("Creating %i (daemon) workers and jobs in child." % num_procs))
pool = multiprocessing.Pool(num_procs)
result = pool.map(sleepawhile,
[randint(1, 5) for x in range(num_procs)])
# The following is not really needed, since the (daemon) workers of the
# child's pool are killed when the child is terminated, but it's good
# practice to cleanup after ourselves anyway.
pool.close()
pool.join()
return result
[docs]def test():
print("Creating 5 (non-daemon) workers and jobs in main process.")
pool = MyPool(5)
result = pool.map(work, [randint(1, 5) for x in range(5)])
pool.close()
pool.join()
print(result)
if __name__ == '__main__':
test()