# CS 450: Process example 5: Address space of child processes in Python
# version 2014-01-21 7:13 PM
#
from multiprocessing import Process

glovar = 1

def go_proc():
	for i in range(5):
		# Create each process, have it run say_hello(i)
		# then print child's process id & our global var
		#
		p = Process(target=say_hello, args=([i]))
		    # (Note list of argument values)
		p.start()
		print('Started process {}'.format(p.pid))
		print('glovar = {}'.format(glovar))

# Each child prints global var before and after
# setting it to 2 * its process id
#
def say_hello(id):
	global glovar
	glovar_init = glovar
	glovar = id * 2 # twice our process id
	print('Child {}, glovar was {}, setting it to {}'.format(id, glovar_init, glovar))

go_proc()	# run the main program

# Sample output
#
# Started process 2886
# glovar = 1
# Started process 2887
# glovar = 1
# Child 0, glovar was 1, setting it to 0
# Started process 2888
# glovar = 1
# Child 1, glovar was 1, setting it to 2
# Started process 2889
# glovar = 1
# Child 2, glovar was 1, setting it to 4
# Started process 2890
# glovar = 1
# Child 3, glovar was 1, setting it to 6
# Child 4, glovar was 1, setting it to 8