PROCESS_DATA:
while(1){

    if( scalar @ready > 0 ){

         if( my $data = shift @to_be_processed ){
            my $t = shift(@ready);
            $shash{$t}{'data'} = $data;
            $shash{$t}{'go'} = 1; 
            print "thread $t restarting\n";
          }else{ print "out of input\n"; last PROCESS_DATA;  }
     }
} # end PROCESS_DATA