What exactly do you want to do in the threads? There's no exhaustive computation to parallelise. Reading from a single file in multiple threads tends to be slower than reading from it in a single thread (not sure about SSD).
map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]