Example #1
0
class Link:
	"""Represents a unidirectional link."""

	def __init__(self, source, dest, prop_delay, bandwidth):
		"""Creates a Link between the specified Hosts.
		This also registers the Link with the source."""
		self.source = source
		self.dest = dest
		source.routing[dest.ip] = self
		self.prop_delay = prop_delay
		self.bandwidth = bandwidth
		self.__mutex = Mutex()
	
	def __log(self, fmt, *args):
		logging.getLogger(__name__).info('link %s->%s '+fmt, self.source.ip, self.dest.ip, *args)

	def enqueue(self, packet):
		"""Called to place this packet in the queue."""
		def send():
			self.__log('queue-start %d', packet.id)
			self.__mutex.lock()
			self.__log('queue-end %d', packet.id)
			
			self.__log('transmit-start %d', packet.id)
			sim.sleep(packet.size / self.bandwidth)
			self.__log('transmit-end %d', packet.id)
			self.__mutex.unlock()
			
			self.__log('propogate-start %d', packet.id)
			sim.sleep(self.prop_delay)
			self.__log('propogate-end %d', packet.id)
			self.dest.received(packet)
		sim.new_thread(send)
Example #2
0
class Link:
    """Represents a unidirectional link."""

    id_counter = itertools.count()

    @staticmethod
    def duplex_link(node1, node2, prop_delay, bandwidth):
        link1 = Link(node1, node2, prop_delay, bandwidth)
        link2 = Link(node2, node1, prop_delay, bandwidth)
        node1.add_link(link1, link2)
        node2.add_link(link2, link1)
        return link1, link2

    def __init__(self, source, dest, prop_delay, bandwidth):
        """Creates a Link between the specified Hosts.
		This also registers the Link with the source."""
        self.source = source
        self.dest = dest
        self.prop_delay = prop_delay
        self.bandwidth = bandwidth
        self.id = next(Link.id_counter)
        self.loss = 0.0

        self.__max_queue_size = 48
        self.__queue = []
        self.__mutex = Mutex()

    def __log(self, fmt, *args):
        logging.getLogger(__name__).info("link %s->%s " + fmt, self.source.ip, self.dest.ip, *args)

    def enqueue(self, packet, priority=3):
        """Called to place this packet in the queue."""
        if random.random() < self.loss:
            self.__log("packet-loss %d", packet.id)
        elif len(self.__queue) >= self.__max_queue_size:
            self.__log("queue-overflow %d", packet.id)
        else:
            heapq.heappush(self.__queue, (priority, packet))
            self.__log("queue-start %d", packet.id)
            sim.new_thread(self.send)

    def send(self):
        self.__mutex.lock()
        priority, packet = heapq.heappop(self.__queue)
        self.__log("queue-end %d", packet.id)

        self.__log("transmit-start %d", packet.id)
        sim.sleep(len(packet) / self.bandwidth)
        self.__log("transmit-end %d", packet.id)
        self.__mutex.unlock()

        self.__log("propogate-start %d", packet.id)
        sim.sleep(self.prop_delay)
        self.__log("propogate-end %d", packet.id)
        self.dest.received(packet, self)
Example #3
0
	def __init__(self, source, dest, prop_delay, bandwidth):
		"""Creates a Link between the specified Hosts.
		This also registers the Link with the source."""
		self.source = source
		self.dest = dest
		source.routing[dest.ip] = self
		self.prop_delay = prop_delay
		self.bandwidth = bandwidth
		self.__mutex = Mutex()
Example #4
0
    def __init__(self, source, dest, prop_delay, bandwidth):
        """Creates a Link between the specified Hosts.
		This also registers the Link with the source."""
        self.source = source
        self.dest = dest
        self.prop_delay = prop_delay
        self.bandwidth = bandwidth
        self.id = next(Link.id_counter)
        self.loss = 0.0

        self.__max_queue_size = 48
        self.__queue = []
        self.__mutex = Mutex()