"""
  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 *

class Shared:
    def __init__(self, end=10):
        self.counter = 0
        self.end = end
        self.array = [0]* self.end
        self.mutex = Semaphore(1)

def child_code(shared):
    while True:
        shared.mutex.wait()
        if shared.counter < shared.end:
            shared.array[shared.counter] += 1
            shared.counter += 1
            shared.mutex.signal()
        else:
            shared.mutex.signal()
            break

class Histogram(dict):
    def __init__(self, seq=[]):
        for item in seq:
            self[item] = self.get(item, 0) + 1

shared = Shared(1000000)
children = [Thread(child_code, shared) for i in range(2)]
for child in children: child.join()
print Histogram(shared.array)
