PA1 python

gistfile1.txt

"""
python 2.7.1 (cpython)
"""

from threading import BoundedSemaphore, Thread


class Png(Thread):
    def __init__(self,string,lock1,lock2,times):
        super(Png, self).__init__()
        self.lock1 = lock1
        self.lock2 = lock2
        self.msg = string
        self.times = times
        pass

    def run(self):
        for i in xrange(self.times):
            self.lock1.acquire()
            print self.msg
            self.lock2.release()



if __name__=='__main__':
    sema1 = BoundedSemaphore(value=1)
    sema2 = BoundedSemaphore(value=1)
    print "Ready... Set... Go!"
    num_times = 10
    thread1 = Png("Ping",lock1=sema1,lock2=sema2,times=num_times)
    thread2 = Png("Pong",lock1=sema2,lock2=sema1,times=num_times)
    #Block semaphore 2 - so thread2(Pong) that tries to acquire it would be block till
    # thread1(Ping) would release it after starting
    sema2.acquire()
    thread1.start()
    thread2.start()
    thread1.join()
    thread2.join()
    print "Done"