"""
  Copyright 2005 Allen B. Downey

    This file contains an example program from The Little Book of
    Semaphores, available from Green Tea Press, greenteapress.com

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, see http://www.gnu.org/licenses/gpl.html
    or write to the Free Software Foundation, Inc., 51 Franklin St, 
    Fifth Floor, Boston, MA  02110-1301  USA
"""


from threading_cleanup import *
import random

class Shared:
    def __init__(self, start=5):
        self.cokes = start

def consume(shared):
    shared.cokes -= 1
    print shared.cokes

def produce(shared):
    shared.cokes += 1
    print shared.cokes

def loop(shared, f, mu=1):
    while True:
        t = random.expovariate(1.0/mu)
        time.sleep(t)
        f(shared)

shared = Shared()
fs = [consume]*2 + [produce]*2 
threads = [Thread(loop, shared, f) for f in fs]
for thread in threads: thread.join()