Esempio n. 1
0
def receive(sock, filename):
    # Open the file for writing
    try:
        file = open(filename, 'wb')
    except IOError:
        print('Unable to open: ', filename)
        return
    i = 0
    expected_num = 0
    arr_of_pack = []
    while True:
        # Get's next packet
        pkt, addr = udt.recv(sock)
        if not pkt:
            break
        seq_num, data = packet.extract(pkt)
        print('Got packet :', seq_num)

        # Send back ACK dependent on if it is correct
        if seq_num == expected_num:
            print('Got expected Packet')
            print('Sending ACK :', expected_num)
            pkt = packet.make(expected_num)
            udt.send(pkt, sock, addr)
            file.write(data)
            expected_num += 1

            if len(arr_of_pack) > expected_num:
                i = expected_num
                if arr_of_pack[expected_num] != 0:
                    while i < len(arr_of_pack) and arr_of_pack[i] != 0:
                        print('Writing cashed line to file.')
                        file.write(arr_of_pack[i])
                        i = i + 1

                    expected_num = i

        else:
            pkt2, _ = udt.recv(sock)
            print('Staching duplicate or out of order Packet :', seq_num)
            if seq_num >= len(arr_of_pack):
                missing = seq_num + 1 - len(arr_of_pack)
                i = 0
                while i <= missing:
                    arr_of_pack.append(0)
                    i = i + 1

            arr_of_pack[seq_num] = data
            print('Sending ACK of duplicate or out of order Packet :', seq_num)
            pkt2 = packet.make(seq_num)
            udt.send(pkt2, sock, addr)
    print('File finished closeing')
    file.close()
Esempio n. 2
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def receive_gbn(sock):
    global base
    global timer
    global mutex

    # We have to make sure the connection is active, so the receiving logic
    # of the sender is within this try-catch block
    try:
        while True:

            # We wait to receive a packet
            ack, addr = udt.recv(sock)

            # To avoid race conditions with the sending mechanism, we use the mutex
            with mutex:

                # If the address of the sender is from the recipient or ours,
                # extract the data
                if addr == RECEIVER_ADDR or addr == SENDER_ADDR:
                    seqnum, payload = packet.extract(ack)

                    # If the packet is from us and the payload is FIN,
                    # we signal the end of the receiving process to the main thread
                    # and exit the listening loop
                    if addr == SENDER_ADDR and payload == b'FIN':
                        print("File sent successfully.\nClosing connection...")
                        timer.stop()
                        break

                    # If we receive an ACK for a packet in the window, move the
                    # base up to the packet following the ACK's sequence number
                    if seqnum >= base and payload == b'ACK':
                        base = seqnum + 1
                        timer.stop()
    except ConnectionError as e:
        print(e)

    # Here, we can assume we already sent the file and are waiting for the
    # client to close the connection. With a try-catch, we simply wait for the
    # exception to happen, stop the time to signal the sender, and print
    # that the connection was closed successfully
    try:
        while True:
            waste = udt.recv(sock)
    except ConnectionError as e:
        with mutex:
            timer.stop()
            print("Connection closed successfully.")
Esempio n. 3
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def receive_snw(sock):
    endStr = ''
    while endStr != 'END':
        pkt, senderaddr = udt.recv(sock)
        seq, data = packet.extract(pkt)
        endStr = data.decode()
        print("From: ", senderaddr, ", Seq# ", seq, endStr)
def receive(sock, filename):
    # Open the file for writing
    try:
        file = open(filename, 'wb')
    except IOError:
        print('Unable to open', filename)
        return

    expected_num = 0  #expected seq no of the packet received
    while True:
        # Get the next packet from the sender
        pkt, addr = udt.recv(sock)  #these udt functions are defined in udt.py
        if not pkt:
            break
        seq_num, data = packet.extract(pkt)
        print('Got packet', seq_num)

        # Send back an ACK
        if seq_num == expected_num:
            print('Got expected packet')
            print('Sending ACK', expected_num)
            pkt = packet.make(
                expected_num,
                '')  # ''implies an empty string because it's an ACK
            udt.send(pkt, sock, addr)
            expected_num += 1
            file.write(
                data)  #this copies the data into a.txt, initially it is empty
        else:
            print('Sending ACK', expected_num - 1)
            pkt = packet.make(expected_num - 1, '')
            udt.send(pkt, sock, addr)

    file.close()
Esempio n. 5
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def receive_gbn(sock):
    end = ""
    packetSeq = 0
    sock.settimeout(10)
    try:
        receivedData = open("receivedData.txt", "a")
        while end != "END":
            try:
                pcket, senderAddress = udt.recv(sock)
            except socket.timeout():
                print("Time out")
                break
            seq, packetData = packet.extract(pcket)
            print("Packet received: ", seq)
            print("Packet Data: ", packetData)

            if packetSeq != seq:
                print("Ack: ", packetSeq - 1)
                pcket = packet.make(packetSeq - 1)
                udt.send(pcket, sock, senderAddress)

            else:
                end = packetData.decode()
                pcket = packet.make(packetSeq)
                udt.send(pcket, sock, senderAddress)
                receivedData.write(end)
                packetSeq += 1

    except IOError:
        print(IOError)
        return
Esempio n. 6
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def receive_snw(sock, pkt):

    endStr = ''

    global seq

    while endStr != 'END':
        pkt, senderaddr = udt.recv(sock)
        rSeq, data = packet.extract(pkt)

        #if received sequence from Receiver socket match sequence from this
        #Sender then alternate seq from 0 or 1 and break out while loop.
        if (rSeq == seq):
            if (seq == 0):
                seq = 1
            else:
                seq = 0
            break
        #Otherwise wrong sequence was received, resend correct sequence and data.
        else:
            print("Mismatched acks, resending")
            udt.send(pkt, sock, RECEIVER_ADDR)

        #Condition to check if timeout has been reach to end loop.
        if stop_event.is_set():
            break
Esempio n. 7
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def receive(sock):
    global mutex
    global base
    global send_timer
    while True:
        pkt, _ = udt.recv(sock)
        ack_pack = packet.my_unpack(pkt)
        """
        - Actualizar la base
        - Detener el timer
        - Recuerde utilizar mutex para las actualizaciones
        """

        # print('Got ACK', ack_pack.ack)
        if (ack_pack.ack >= base):
            mutex.acquire()
            base = ack_pack.ack + 1
            # print('Base updated', base)
            send_timer.stop()
            mutex.release()

        if not send_timer.running():
            break

        mutex.acquire()
        if end_conn_timer:
            mutex.release()
            raise Exception('WAITING TIME EXCEDED')
Esempio n. 8
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def receive_snw(sock, pkt):
    global base
    global timer
    global mutex

    while base < len(pkt):
        # get out packet and server packet
        currentSequence, _ = packet.extract(pkt[base])
        try:
            acknowledgement, _ = udt.recv(sock)
        except:
            print('*** ERROR: LOST CONNECTION TO SERVER')
            sys.exit(1)
        acknowledgement = int(acknowledgement.decode())
        currentSequence = int(currentSequence)

        # see if we got the correct ack
        if acknowledgement == currentSequence:
            mutex.acquire()
            base += 1
            timer.stop()
            mutex.release()
        else:
            print('\n*** ERROR: Received Incorrect Acknowledgement ***\n')
            print('Expected Acknowledgement: %i' % currentSequence)
            print('Received Acknowledgement: %i' % acknowledgement)
    sys.exit(0)
Esempio n. 9
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def receive(sock, filename):
    # Open the file for writing
    try:
        file = open(filename, 'wb')
    except IOError:
        print('Unable to open', filename)
        return

    expected_num = 0
    while True:
        # Get the next packet from the sender
        pkt, addr = udt.recv(sock)
        if not pkt:
            break
        seq_num, data = packet.extract(pkt)
        print('Got packet', seq_num)

        # Send back an ACK
        if seq_num == expected_num:
            print('Got expected packet')
            print('Sending ACK', expected_num)
            pkt = packet.make(expected_num)
            udt.send(pkt, sock, addr)
            expected_num += 1
            file.write(data)
        else:
            print('Sending ACK', expected_num - 1)
            pkt = packet.make(expected_num - 1)
            udt.send(pkt, sock, addr)

    file.close()
Esempio n. 10
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def receive_gbn(sock, sent):
    global received_packets
    global num_resent_packets
    global current_ack
    sock.settimeout(0.5)
    acknowledged = len(sent)
    count = 0
    while count != acknowledged:
        try:
            for x in range(len(sent)):
                ACK, senderaddr = udt.recv(sock)
                ack, data = packet.extract(ACK)
                if ack not in received_packets and current_ack == ack:
                    print("Confirm seq#: ", ack, "\n")
                    received_packets.append(ack)
                    sent.remove(ACK)
                    current_ack += 1
                    count += 1

        except socket.timeout:
            print("Resending")
            for x in sent:
                udt.send(x, sock, RECEIVER_ADDR)
                num_resent_packets += 1
    return
Esempio n. 11
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def receive_gbn(sock, filename):
    # try to pen file for writing else throw error
    try:
        file = open(filename, 'wb')
    except IOError:
        print("Cannot open %s" % filename)
        return

    expected_seq = 0
    while True:
        pkt, addr = udt.recv(sock)  # receive packet and check if it's valid
        if not pkt:  # if we receive a sentinel packet break receive
            break
        seq, data = packet.extract(pkt)  # extract packet sequence number
        print("Received packet: %s" % seq)

        if seq == expected_seq:  # if received sequence # is the expected sequence # send ACKs
            print("Received expected packet\nSending ACK: %s" % seq)
            pkt = packet.make(seq)
            udt.send(pkt, sock, addr)
            expected_seq += 1  # increment next expected sequence # and write data to file
            print("Writing data to file")
            file.write(data)
        else:  # if not expected sequence # then send ACK for most recent ingested packet
            print("Sending ACK for latest packet: %s" % (expected_seq - 1))
            pkt = packet.make(expected_seq - 1)
            udt.send(pkt, sock, addr)

    file.close()
Esempio n. 12
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def receive_snw(sock, pkt): #Mod rcvr by Jennifer
    global threads, sync
    threads += 1 #Put name in hat

    while not sync: #Spin Lock to Synchronize Execution
        continue

    while pkt_buffer: #While Packets still need to be sent
        mutex.acquire() #Lock
        print("2 - Acquired") #DEBUG

        timer.start() #Restart TTL
        p = pkt.pop() #Get next pkt

        #Checks for final ACK
        retry = RETRY_ATTEMPTS
        while retry:
            try:
                # Try ACK Check
                ack, recvaddr = udt.recv(sock)

                # If received, cleanup and pass baton
                timer.stop() 
                mutex.release()
                time.sleep(SLEEP_INTERVAL)
                retry = RETRY_ATTEMPTS
                break

            except BlockingIOError:
                # Otherwise, check timer and restart
                if timer.timeout():
                    retry -= 1
                    udt.send(p, sock, RECEIVER_ADDR)
                    timer.start()
    threads -= 1 #Remove name from hat
Esempio n. 13
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def receive(sock):
    global mutex

    expected_num = 0
    while True:
        mutex.acquire()
        pkt, addr = udt.recv(sock)
        if not pkt:
            break
        seq_num, data = packet.extract(pkt)  # packet 수신
        print('Got packet', seq_num)

        if seq_num == expected_num:  # 오류 없이 수신되는 경우
            print('Expected packet. Sending ACK', expected_num)
            pkt = packet.make(expected_num)
            udt.send(pkt, sock, addr)
            rtt_q.append([pkt, sock, addr])
            rtt_timer.append(time.time())
            expected_num += 1
        else:  # 오류로 인해 순서가 잘못 수신되는 경우
            print('Unexpected packet. Sending ACK', expected_num - 1)
            pkt = packet.make(expected_num - 1)
            udt.send(pkt, sock, addr)
            rtt_q.append([pkt, sock, addr])
            rtt_timer.append(time.time())

        time.sleep(UNIT_TIME)
        mutex.release()
Esempio n. 14
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def receive(sock, filename, drop_prob):
    try:
        file = open(filename, 'wb')
    except IOError:
        print('Unable to open', filename)
        return

    expected_num = 0
    while True:
        pkt, addr = udt.recv(sock)
        if not pkt:
            break
        seq_num, data = packet.extract(pkt)
        print('Got packet', seq_num)

        if seq_num == expected_num:
            print('Sending ACK', expected_num)
            pkt = packet.make(expected_num)
            udt.send(pkt, sock, addr, drop_prob)
            expected_num += 1
            file.write(data)
        else:
            print('Sending ACK', expected_num - 1)
            pkt = packet.make(expected_num - 1)
            udt.send(pkt, sock, addr, drop_prob)

    file.close()
Esempio n. 15
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def receive_snw(sock):
    endStr = ''
    expectedPacket = 0

    # While FIN packet has not been received
    while endStr != 'END':
        pkt, senderaddr = udt.recv(sock)
        SEQ, data = packet.extract(pkt)
        endStr = data.decode()
        print("From: ", senderaddr, ", SEQ# ", SEQ)

        # The received packet was not expected. Send ACK with the correct SEQ number
        if expectedPacket != SEQ:
            print(
                'This packet was not expected. Sending ACK %d' %
                expectedPacket, "\n")
            pkt = packet.make(expectedPacket)
            udt.send(pkt, sock, senderaddr)

        # This packet was expected. Send ACK with the next SEQ number expected
        else:
            print(
                'Successfully received SEQ #%d. Sending ACK #%d' %
                (SEQ, expectedPacket), "\n")
            pkt = packet.make(expectedPacket)
            udt.send(pkt, sock, senderaddr)
            expectedPacket += 1

            # Makes sure that the FIN packet is not added to the text
            if endStr != 'END':
                file.write(data.decode())

    print('FIN has been ACK... Ending connection')
Esempio n. 16
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def receive_gbn(sock):
    # Fill here
    sock.settimeout(10)
    try:  # open file
        file = open('./files/receiver_bio.txt', 'a')
    except:  # cannot create file
        print('Could Access location')
        sys.exit(1)

    previous = -1
    while True:
        try:
            clientPacket, clientAddress = udt.recv(sock)
        except:
            print('Server Shutting Down')
            sys.exit(1)

        clientSequence, clientData = packet.extract(clientPacket)
        print('Received client sequence', clientSequence)
        if previous + 1 == clientSequence:
            file.write(clientData.decode())  # write data to file
            previous = clientSequence  # update last seen client sequence
        acknowledgement = packet.make(clientSequence,
                                      str(clientSequence).encode())
        udt.send(acknowledgement, sock, clientAddress)

    return
Esempio n. 17
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def receive_snw(sock, pkt):

    global base
    global timer
    global mutex
    ackedpackets = 0
    #use try in case of connection error
    try:
        #get the sequence number and payload from the packet passed in as a parameter
        #this contains the final sequence number and payload data in that packet
        fseqnum, fpayload = packet.extract(pkt)

        #ackedpacket is counting the total ACKS from Receiver.py
        #this loop runs until an ACK is received that is one number higher
        #than previously received because there is one final packet sent
        #when the payload packets are done
        while ackedpackets < fseqnum + 1:
            # unpack the ack packet received and increment ackpackets counter
            ack, addr = udt.recv(sock)
            ackedpackets += 1

            with mutex:
                #unpack the seqnum and payload and update base so send_snw
                #knows to send the next packet in the sequence
                seqnum, payload = packet.extract(ack)
                base = seqnum + 1
                #stop the timer because ACK was successfully reeived
                timer.stop()

    except ConnectionError as e:
        #mutex.release()
        print(e)
Esempio n. 18
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def receive_gbn(sock):
    initSeq = 0
    seqList = [] #Holds Sequence numbers prev received
    f = open("receiver_bio.txt", "w")
    dataStr = ''

    while True:
    #while dataStr!='END':
       #print("In true loop") #DEBUG
       pkt, senderaddr = udt.recv(sock)
       seq, data = packet.extract(pkt)
       dataStr = data.decode()

       #Does not write if duplicate pkt or FIN pkt 
       #print("data is "+data.decode()) #DEBUG
       print("receiver seq:%d, sender gave:%d" %(initSeq, seq))
       #print("data:%s" %(dataStr))
       if (seq == initSeq and not dataStr == "END"):
          #print("packet fine, writing to file")
          f.write(dataStr)
          ack = packet.make(initSeq, "ACK".encode())
          initSeq = initSeq+1
          udt.send(ack, sock, senderaddr)
       elif not seq == initSeq:
            #print("Not in ordered pkt received")
            ack = packet.make(initSeq, "ACK".encode())
       elif dataStr == 'END':
        print("Received end, we're done")
        break
    f.close() 
Esempio n. 19
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def receive_gbn(sock):
    seqList = []  #Holds Sequence numbers prev received
    f = open("gbn_receiver.txt", "w")
    dataStr = ''

    #While NO FIN pkt
    while dataStr != 'END':
        pkt, senderaddr = udt.recv(sock)
        seq, data = packet.extract(pkt)
        dataStr = data.decode()

        #Does not write if duplicate pkt or FIN pkt
        #print("data is "+data.decode()) #DEBUG
        if (seq not in seqList and not dataStr == "END"):
            f.write(dataStr)

        #Data recv, ensure duplicate packets are ignored
        seqList.append(seq)
        #print("From: ", senderaddr, ", Seq# ", seq, dataStr) #DEBUG

        #Send back ACK to confirm rcpt.
        #If ACK lost, retransmission happens on sender side :)
        ack = packet.make(seq, "ACK".encode())
        udt.send(ack, sock, senderaddr)

        #TODO
        #I think instead of checking against an entire list we can
        #just have it check to see if ACK is
        #Sends ACK back to sender to confirm receipt
        #Obviously a list is unfeasible for modern comms
        #Ex.) Imagine trying to hold a list of ACKs for 512b from a 5GB file??
        #     That would be like 10 million numbers lol

    f.close()
Esempio n. 20
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def receive_gbn(sock):

    # Shared Resource Access
    global sync, base, sending, receiving

    # Spin lock to synchronize execution
    while not sync:
        continue

    retry = RETRY_ATTEMPTS + 1

    base = 0

    # Retry Loop
    while retry and (pkt_buffer or sending):

        with mutex:

            if timer.timeout() or not timer.running():
                retry -= 1
                timer.start()

            print("\n[I] RECV - Acquired Lock")

            for i in range(WINDOW_SIZE):

                try:
                    # Try ACK Check
                    ack, recvaddr = udt.recv(sock)
                    seq, ack_data = packet.extract(ack)

                    # Check for base packet reception
                    if seq == base:

                        print("[I] RECV - Got ACK Seq# {}".format(seq))

                        #sys.stderr.write("ACK on Seq# {}\n".format(seq))
                        #sys.stderr.flush()

                        base += 1
                        pkt_buffer.pop(0)
                        timer.stop()
                        retry = RETRY_ATTEMPTS + 1
                        continue

                    print(
                        "[W] RECV - Got Wrong ACK Seq# {}, Expected {}".format(
                            seq, base))

                except BlockingIOError:
                    continue

        time.sleep(SLEEP_INTERVAL)

    receiving = False

    print("[I] RECV - Terminating Thread")
    return
Esempio n. 21
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def mod_receive_snw(sock):
    endStr = ''
    f = open("bio2.txt", "w")
    while endStr != 'END':
        pkt, senderaddr = udt.recv(sock)
        seq, data = packet.extract(pkt)
        endStr = data.decode()
        print("From: ", senderaddr, ", Seq# ", seq, endStr)
        if (endStr != 'END'):
            f.write(endStr)
    f.close()
Esempio n. 22
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def receive_snw(sock):
    endStr = ''
    _seq = -1
    while endStr != 'END':
        pkt, senderaddr = udt.recv(sock)
        seq, data = packet.extract(pkt)
        if _seq != seq:
            _seq = seq
            endStr = data.decode()
            print("From: ", senderaddr, ", Seq# ", seq, endStr)
        udt.send(b' ', sock, ('localhost', 9090))
Esempio n. 23
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def receive_sr(sock, windowsize):
    sock.settimeout(5)
    while True:
        try:
            pkt, senderAddr = udt.recv(sock)
        except:
            print('Shutting Down Server')
            sys.exit(1)
        seq, data = packet.extract(pkt)
        print(seq)
        ack = str(seq).encode()
        udt.send(ack, sock, senderAddr)
Esempio n. 24
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def receive_snw(sock):
    endStr = ''
    f = open("receiver_file_x.txt", "w")
    while endStr != 'END':
        pkt, senderaddr = udt.recv(sock)
        seq, data = packet.extract(pkt)
        endStr = data.decode()
        if endStr != "END":
            f.write(endStr)
        print("From: ", senderaddr, ", Seq# ", seq, "Data ", endStr, "\n")
        pkt = packet.make(seq, data)
        udt.send(pkt, sock, senderaddr)
Esempio n. 25
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def receive_snw(sock, pkt):
    sock.settimeout(0.5)
    acknowledged = False
    while not acknowledged:
        try:
            ACK, senderaddr = udt.recv(sock)
            ack, data = packet.extract(ACK)
            print("Confirm seq#: ", ack, "\n")
            acknowledged = True
        except socket.timeout:
            print("Resending")
            udt.send(pkt, sock, RECEIVER_ADDR)
    return
Esempio n. 26
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def receive_gbn(sock):
    # Fill here to handle acks
    global base, timer, mutex
    end = ''
    while end != 'END':
        pkt, senderaddr = udt.recv(sock)
        seq, data = packet.extract(pkt)
        end = data.decode()
        print("From: ", senderaddr, ", Seq# ", seq, end)
        if seq >= base:
            mutex.acquire()
            base = seq + 1
            timer.stop()
            mutex.release()
Esempio n. 27
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def receive(sock):
    global mutex
    global base
    global send_timer

    while True:
        pkt, _ = udt.recv(sock)
        ack, _ = packet.extract(pkt)

        print('Got ACK', ack)
        if ack >= base:
            mutex.acquire()
            base = ack + 1
            send_timer.stop()
            mutex.release()
Esempio n. 28
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def receive_snw(sock, pkt):

    # Shared Resource Access
    global sync, alive

    # Spin lock to synchronize execution
    while not sync:
        continue

    # While Packets still exist
    while pkt_buffer:

        # Manually lock
        mutex.acquire()

        # Debugging info
        print("[I] RECV - Acquired Lock")

        # Retry Delay
        timer.start()

        # Get Packet
        p = pkt.pop()

        # R
        retry = RETRY_ATTEMPTS
        while retry:
            try:
                # Try ACK Check
                ack, recvaddr = udt.recv(sock)

                # If received, cleanup and pass baton
                timer.stop()
                mutex.release()
                time.sleep(SLEEP_INTERVAL)
                retry = RETRY_ATTEMPTS
                break

            except BlockingIOError:

                # Otherwise, check timer and restart
                if timer.timeout():
                    retry -= 1
                    udt.send(p, sock, RECEIVER_ADDR)
                    timer.start()

    # Remove name from hat
    alive = False
Esempio n. 29
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def receive_gbn(sock, sent):
    sock.settimeout(0.5 * 50)
    acknowledged = len(sent)
    count = 0
    while count != acknowledged:
        try:
            for x in range(len(sent)):
                ACK, senderaddr = udt.recv(sock)
                ack, data = packet.extract(ACK)
                print("Confirm seq#: ", ack, "\n")
                acknowledged += 1
        except socket.timeout:
            print("Resending")
            for x in sent:
                udt.send(x, sock, RECEIVER_ADDR)
    return
Esempio n. 30
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def receive_snw(sock):
    endStr = ''
    _seq = -1
    while True:
        pkt, senderaddr = udt.recv(sock)
        seq, data = packet.extract(pkt)
        if _seq != seq:
            _seq = seq
            endStr = data.decode()
            sys.stderr.write("From: {}, Seq# {}\n".format(senderaddr, seq))
            sys.stderr.flush()
            if endStr == 'END':
                return
            sys.stdout.write(endStr)
            sys.stdout.flush()
        udt.send(b' ', sock, ('localhost', 9090))
Esempio n. 31
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def receive(sock):
    global mutex
    global base
    global send_timer

    while True:
        pkt, _ = udt.recv(sock);
        ack, _ = packet.extract(pkt);

        # If we get an ACK for the first in-flight packet
        print('Got ACK', ack)
        if (ack >= base):
            mutex.acquire()
            base = ack + 1
            print('Base updated', base)
            send_timer.stop()
            mutex.release()