import sys
from multiprocessing import *

if sys.version_info < (3, 0):
    latin = str
else:
    def latin(s):
        return s.encode('ascii')

SENTINEL = latin('')

def _echo(self, conn):
    for msg in iter(conn.recv_bytes, SENTINEL):
        conn.send_bytes(msg)
    conn.close()

conn, child_conn = Pipe()

p = Process(target=_echo, args=(child_conn,))
#p.set_daemon(True)
p.start()

really_big_msg = latin('X') * 10 #(1024 * 1024 * 32)
conn.send_bytes(really_big_msg)
assert conn.recv_bytes() == really_big_msg

conn.send_bytes(SENTINEL)                          # tell child to quit
child_conn.close()