coupled timer fail

ev3.pl

use AnyEvent;
use EV;

my $cv = AE::cv;

my $t = AE::timer 2,0, sub{
    my $cv2 = AE::cv;
    my $cnt = 10;
    my $tot = 0;

    foreach(1..10){
        my $idx = $_;
        my $tt; $tt = AE::timer 1,0,sub{
            print "t $idx\n";
            $tot+=$idx;
            $cnt--;
            undef($tt);
        }
    }

    while($cnt){
        AnyEvent->_poll;
        print "t idle\n";
    } # wait

    print "t tot: $tot\n";

};

my $t2= AE::timer 2,0, sub{
    my $cv2 = AE::cv;
    my $cnt = 10;
    my $tot = 0;

    foreach(1..10){
        my $idx = $_;
        my $tt; $tt = AE::timer $idx,0,sub{
            print "t2 $idx\n";
            $tot+=$idx;
            $cnt--;
            undef($tt);
        }
    }

    while($cnt){
        AnyEvent->_poll;
        print "t2 idle\n";
    } # wait

    print "t2 tot: $tot\n";

};


$cv->recv;
print "DONE\n";