use strict;
use Thread;

my $time : shared;
my $t = Thread->new(\&listener,\$time);

while (1) {
    $time = localtime;
    print $time,"\n";
    sleep 1;
}

sub listener {
    my $time_ref = shift;
    while (1) {
        {
            lock($$time_ref);
            print "\tThread time: [$time]\n";
            print "\tThread time: [$main::time]\n";
            print "\tThread time: [$$time_ref]\n";
        }
        sleep 3;
    }
}