def process(self):
if (self.link.buf_processing or self.link.buffer_empty()):
return
else:
self.link.buf_processing = True
assert (self.link.buffer_empty() == False)
packet, src = self.link.buffer_get()
send_time = packet.size / self.link.rate + self.link.prop_delay
receiver = self.link.get_receiver(src)
enqueue(ReceivePacket(self.start_time + send_time, packet, \
self.link, receiver))
next_pkt, next_src = self.link.buffer_peek()
if next_src is not None:
next_dest = self.link.get_receiver(next_src)
else:
next_dest = None
# if next_dest is None or self.link.curr_recipient != next_dest:
if next_dest is not None and self.link.curr_recipient != next_dest and HALF_DUPLEX:
self.link.curr_recipient = next_dest
done_time = packet.size / self.link.rate + self.link.prop_delay
else:
done_time = packet.size / self.link.rate
enqueue(
BufferDoneProcessing(self.start_time + done_time, self.link))
def receive(self, pkt, time):
# Pass ACKs to flows to handle congestion control and dropped packets
if (isinstance(pkt, packet.Ack)):
pkt.flow.receiveAck(pkt, time)
else:
# Only send ACKs for packets we have not yet recieved
# (next_pkt = pkt.number) or packets out of order
# (next_pkt < pkt.number).
# If first packet from flow, then set expected_pkt to 0.
if self.expected_pkt.setdefault(pkt.flow.id, 0) <= pkt.number:
# If the packet is the one we're expecting,
# increment its value in next_packet.
if self.expected_pkt[pkt.flow.id] == pkt.number:
self.expected_pkt[pkt.flow.id] += 1
while self.expected_pkt[pkt.flow.id] in \
self.received_pkts.setdefault(pkt.flow.id, []):
self.received_pkts[pkt.flow.id].remove(
self.expected_pkt[pkt.flow.id])
self.expected_pkt[pkt.flow.id] += 1
else:
self.received_pkts.setdefault(pkt.flow.id,
[]).append(pkt.number)
ack = packet.makeAck(pkt.flow, self.expected_pkt[pkt.flow.id])
enqueue(event.SendPacket(time, ack, self.link, self))
pkt.flow.received_packets += 1
def handleTimeout(self, pkt, curr_time):
# If unacknowledged, resend the packet + its timeout event
if pkt.number in self.unacknowledged:
self.window_size = 1
enqueue(event.SendPacket(curr_time, pkt, self.source.link, \
self.source))
enqueue(event.PacketTimeout(curr_time + self.timeout, pkt))
self.unacknowledged[pkt.number] = curr_time
def broadcast_distvec(self, time):
for rtr_id in self.rneighbours:
link = self.rneighbours[rtr_id]
dest = link.get_receiver(self)
rtPkt = packet.RoutingPkt(self, dest, self.bf_distvec, \
self.bf_round)
enqueue(event.SendPacket(time, rtPkt, link, self))
self.sent_rtpkts[rtPkt] = Router.PKT_SENT
enqueue(
event.RtPktTimeout(time + Router.RTPKT_TIMEOUT, self, rtPkt))
def makePacket(self, payload, number, start_time):
# Makes a new packet and then enqueues SendPacket and PacketTimeout
# events.
pkt = packet.DataPkt(self.source, self.destination, payload, number,
self)
# We send the packet (put the event in the pqueue at the flow's start
# time.
enqueue(
event.SendPacket(start_time, pkt, self.source.link, self.source))
enqueue(event.PacketTimeout(start_time + self.timeout, pkt))
def handle_timeout(self, curr_time, rtpkt):
'''
Handle timeout for a routing packet
'''
status = self.sent_rtpkts.get(rtpkt, None)
# If it's been sent but not acknowledged, resend.
if status == Router.PKT_SENT:
send_link = self.rneighbours[rtpkt.recipient.id]
enqueue(event.SendPacket(curr_time, rtpkt, send_link, self))
# If it's been acknowledged, remove it from the sent list.
elif status == Router.PKT_ACKED:
del self.sent_rtpkts[rtpkt]
def startFlow(self):
# While our window isn't filled yet, we create packets.
while (self.curr_pkt < min(self.num_packets, self.window_size)):
self.makePacket("PACKET %d" % self.curr_pkt, self.curr_pkt,
self.start_time)
if self.TCP_ALG == 'fast':
enqueue(
event.UpdateWindow(self.start_time + self.update_period,
self))
# We keep track of which packets we haven't received ACKS
# for yet.
self.unacknowledged[self.curr_pkt] = self.start_time
self.curr_pkt += 1
self.sent_packets += 1
def receive(self, pkt, time):
# Record ACKed routing packet
if (isinstance(pkt, packet.RtAck)):
self.sent_rtpkts[pkt.rtpkt] = Router.PKT_ACKED
# Handle received routing packet (update BF)
elif (isinstance(pkt, packet.RoutingPkt)):
if self.bf_updated.get(pkt.sender.id, False) == False:
ack_link = self.rneighbours[pkt.sender.id]
rt_ack = packet.RtAck(pkt)
enqueue(event.SendPacket(time, rt_ack, ack_link, self))
if pkt.bf_round == self.bf_round:
self.update_bf(pkt.sender.id, pkt.distvec, ack_link, time)
# Forward packet on according to routing table
else:
next_link = link.Link.l_map[self.routing_table[pkt.recipient.id]]
enqueue(event.SendPacket(time, pkt, next_link, self))
def process(self):
# Debugging output
cprint("==================================")
cprint("Rerouting round %d" % self.round_no)
# Update link costs, trigger rerouting, and enqueue the event
# for the next rerouting
link.set_linkcosts()
router.reset_bf(self.start_time, self.round_no)
enqueue(
Reroute(self.start_time + Reroute.WAIT_INTERVAL,
self.round_no + 1))
# Debugging output
cprint("Link costs:")
coststr = ""
for l_id in link.Link.ids:
coststr += "%s: %d " % (l_id, link.Link.l_map[l_id].bf_lcost)
cprint(coststr)
cprint("\nRouting tables:")
for r_id in router.Router.ids:
cprint(r_id + str(router.Router.r_map[r_id].routing_table))
cprint("==================================")
def process(self):
enqueue(CheckBuffer(
self.start_time,
self.link,
))
self.receiver.receive(self.packet, self.start_time)
def process(self):
self.link.buf_processing = False
self.link.size_in_transit = 0
enqueue(CheckBuffer(self.start_time, self.link))
def process(self):
self.link.buffer_add((self.packet, self.sender))
enqueue(CheckBuffer(self.start_time, self.link))
def process(self):
self.flow.window_size = self.flow.fast_window()
enqueue(UpdateWindow(self.start_time + self.flow.update_period, \
self.flow))
cprint('%s updated window to %d' %
(self.flow.id, self.flow.window_size))