Consider the sender and receiver below, show a scenario that they enter into a deadlock state.

rdt_send (data) sndpkt-make_pkt (0, data, checksum) udt_send (sndpkt) rdt_rev (revpkt) && (corrupt (revpkt) il iSNAK (revpkt)) udt_send (sndpkt) Wait for call 0 from above Wait for ACK or NAKO rdt_rev (revpkt) && not corrupt (revpkt) && isACK (revpkt) rdt_rev (rcvpkt) && notcorrupt (revpkt) && isACK (rcvpkt) Wait for ACK or NAK 1 Wait for call 1 from above rdt_rev (revpkt) && (corrupt (revpkt) 11 i SNAK (revpkt)) udt_send (sndpkt) rdt_send (data) sndpkt-make_pkt (1, data, checksum) udt_send (sndpkt) sender (a) Sender Side rdt_revrcvpkt) && notcorrupt(revpkt) && has secolrcypkt) extract(revpkt, data) deliver_data(data) compute chksum make_pkt(sndpkt, ACK, chksum) udt_send(sendpkt) Wait for o from below Wait for 1 from below rot_revirevpkt) && (corrupt revpkt) II has secrcypkt)) compute chksum make_pkt(sndpkt, NAK, chksum) udt_send(sndpkt) rdt_rev(revpkt) && (corrupt(revpkt) 11 has seolrevpkt)) compute chksum make_pkt(sndpkt, NAK, chksum) udt_send(sndpkt) rdt_revirevpkt) && notcorrupt revpkt) &&has seol(rcypkt) extract(revpkt, data) deliver_data(data) compute chksum make_pkt(sndpkt, ACK, chksum) udt_send(sendpkt) receiver (b) Receiver Side rdt_send (data) sndpkt-make_pkt (0, data, checksum) udt_send (sndpkt) rdt_rev (revpkt) && (corrupt (revpkt) il iSNAK (revpkt)) udt_send (sndpkt) Wait for call 0 from above Wait for ACK or NAKO rdt_rev (revpkt) && not corrupt (revpkt) && isACK (revpkt) rdt_rev (rcvpkt) && notcorrupt (revpkt) && isACK (rcvpkt) Wait for ACK or NAK 1 Wait for call 1 from above rdt_rev (revpkt) && (corrupt (revpkt) 11 i SNAK (revpkt)) udt_send (sndpkt) rdt_send (data) sndpkt-make_pkt (1, data, checksum) udt_send (sndpkt) sender (a) Sender Side rdt_revrcvpkt) && notcorrupt(revpkt) && has secolrcypkt) extract(revpkt, data) deliver_data(data) compute chksum make_pkt(sndpkt, ACK, chksum) udt_send(sendpkt) Wait for o from below Wait for 1 from below rot_revirevpkt) && (corrupt revpkt) II has secrcypkt)) compute chksum make_pkt(sndpkt, NAK, chksum) udt_send(sndpkt) rdt_rev(revpkt) && (corrupt(revpkt) 11 has seolrevpkt)) compute chksum make_pkt(sndpkt, NAK, chksum) udt_send(sndpkt) rdt_revirevpkt) && notcorrupt revpkt) &&has seol(rcypkt) extract(revpkt, data) deliver_data(data) compute chksum make_pkt(sndpkt, ACK, chksum) udt_send(sendpkt) receiver (b) Receiver Side