"""
This is a simple example of the Producer/Consumer problem in Python.

It makes use of multitask module:
    <http://o2s.csail.mit.edu/o2s-wiki/multitask>
"""
import multitask

class Producer(object):
    def __init__(self, buffer, name, limit=10):
        self.buffer = buffer
        self.name = name
        self.limit = limit
    
    def run(self):
        for i in range(self.limit):
            data = "'%s-%s'" % (self.name, i)
            # task will be resumed after data is in the buffer 
            yield self.buffer.put(data)
            print "%s has put %s in the buffer." % (self.name, data)
            # the task will be resumed after 1 second
            yield multitask.sleep(1)

class Consumer(object):
    def __init__(self, buffer, name):
        self.buffer = buffer
        self.name = name
    
    def run(self):
        while not self.buffer.empty():
            # task will be resumed after an element is available in the queue
            data = (yield self.buffer.get())
            print "%s has got %s from the buffer." % (self.name, data)
            yield multitask.sleep(1.5)
            print "%s is doing something with %s" % (self.name, data)


def main():
    buffer = multitask.Queue()
    prod = Producer(buffer, "Producer")
    cons = Consumer(buffer, "Consumer")
    
    multitask.add(prod.run())
    multitask.add(cons.run())
    
    multitask.run()


if __name__ == '__main__':
    main()