[CentOS] Bash Question

Hey guys,
messing around with a snippet from a mailing list post,


#!/bin/bash

mkfifo -m 666 /var/spool/my_fifo
exec 42<> /var/spool/my_fifo

while true
do
        while read -t 5 data <&42
        do
                echo "data is ($data)"
        done
        echo "read again"
done



What happens to this to invalidate the initial 'true' condition, it only runs
for a short while?

Thanks!
jlc