#! perl -slw
use strict;
use threads;
use Thread::Queue;

my $file = $ARGV[ 0 ];

my $Q = new Thread::Queue;
async {
    open LIBBIN, "gunzip -c $file |" or die $!;
    while( <LIBBIN> ) {
        $Q->enqueue( $_ );
        sleep 1 while $Q->pending > 100;                  ## Arbitrary limit to stop it from running away with memory
    }
    $Q->enqueue( undef ); ## close queue
}->detach;

## Main code swaps $Q->dequeue for <LIBBIN> ...

while( my $line = $Q->dequeue ) {

   if( some circumstance ) {
       unshift @{ $Q->{queue} }, $line;                 ## 'push' a line back to the queue.
   }
   
   ## do other stuff here..
   
}