sub my_sub {
        $hohref = shift;       
    
        # create thread pool
    	my $pool = Thread::Pool::Simple->new(
    		do  => [ \&helper ]
    	);
    
    	# submit jobs
    	foreach my $hashref ( values %{$hohref} ) {
    		$pool->add( $hashref );
    	}
    
    	# wait for all threads to end
    	$pool->join();
        }