# CS 450; Python Process list example
# version 2014-02-09 3:58 PM
#
# Create a list of processes, start them all, then join them all
#
from multiprocessing import Process
import time	# for sleep
import random

# say_hello prints its id and sleeps for a given nbr of seconds
#
def say_hello(id, seconds):
	print('Child {} is running'.format(id))
	time.sleep(seconds)
	print('Child {} is done'.format(id))

def say_hello2(id):
	print('Child {} is running'.format(id))
	time.sleep(random.randint(0, 3))
	print('Child {} is done'.format(id))


# main(nbr_procs) creates a number of procs (default of 5)
# then it starts all the processes, and then it waits until they all finish.
# Each process sleeps for a random number of seconds >= 1 and <= 9),
#
def main(nbr_procs = 5):
	# ps is a list of process objects
	ps = [Process(target=say_hello, args=([i, random.randint(1,9)]))
		for i in range(nbr_procs)]

	for p in ps:
		p.start()
		print('Started process {}'.format(p.pid)) # note: pid field

	for p in ps:
		p.join()
		print('Joined process {}'.format(p.pid))

# main()