my $wt_display_code:shared;
my $wt_data:shared;

$mw->repeat(0.001,sub { display_worker_data() });

sub display_worker_data() {
 
    if($wt_display_code eq "SENT_RECVD") {
       my $data_for_display="Sent recvd: $wt_data";
       $sent_recvd_listbox->insert('end',$data_for_display");
    }elsif($wt_display_code eq "TIME_STATUS") {
       my $data_for_display="Time: $local_time";
       $time_stats_listbox->insert('end',"$data_for_display");
    }elsif(...) {
       ...
    }elsif(...) {
       ...
    } etc...
}