# iotest.py

import time
import threading
from socket import *
import itertools

def task_pidigits():
    """Pi calculation (Python)"""
    _map = map
    _count = itertools.count
    _islice = itertools.islice

    def calc_ndigits(n):
        # From http://shootout.alioth.debian.org/
        def gen_x():
            return _map(lambda k: (k, 4*k + 2, 0, 2*k + 1), _count(1))

        def compose(a, b):
            aq, ar, as_, at = a
            bq, br, bs, bt = b
            return (aq * bq,
                    aq * br + ar * bt,
                    as_ * bq + at * bs,
                    as_ * br + at * bt)

        def extract(z, j):
            q, r, s, t = z
            return (q*j + r) // (s*j + t)

        def pi_digits():
            z = (1, 0, 0, 1)
            x = gen_x()
            while 1:
                y = extract(z, 3)
                while y != extract(z, 4):
                    z = compose(z, next(x))
                    y = extract(z, 3)
                z = compose((10, -10*y, 0, 1), z)
                yield y

        return list(_islice(pi_digits(), n))

    return calc_ndigits, (50, )

def spin():
    task,args = task_pidigits()
    while True:
       r= task(*args)

def echo_server():
    s = socket(AF_INET, SOCK_DGRAM)
    s.setsockopt(SOL_SOCKET, SO_REUSEADDR,1)
    s.bind(("",16000))
    while True:
        msg, addr = s.recvfrom(16384)
        s.sendto(msg,addr)

# Launch threads
NUMTHREADS = 2
for n in range(NUMTHREADS):
    t = threading.Thread(target=spin)
    t.setDaemon(True)
    t.daemon = True
    t.start()

# Launch a background echo server
echo_server()