class Server(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)
        self.queue = []

    def run(self):
        self.context = zmq.Context()

        self.frontend = self.context.socket(zmq.ROUTER)
        self.frontend.bind('tcp://*:5570')

        self.poller = zmq.Poller()
        self.poller.register(self.frontend, zmq.POLLIN)

        self.processor = Processor()

        while True:
            while len(self.queue) < 8:
                sockets = dict(self.poller.poll())

                # queue up messages
                if self.frontend in sockets:
                    ident, zf, msg = self.frontend.recv_multipart()
                    tprint('Server received %s from %s' % (msg, ident))
                    self.queue.append([ident, zf, msg])
                else:
                    break

            # process queue
            tprint('Processing batch of size %d' % len(self.queue))
            result = self.processor.process(self.queue)
            for message in result:
                self.frontend.send_multipart(message)
            self.queue = []