[Catalyst] How to redirect before some code excute

[fayland]

i want to redirect before the loop  excute , but it seems redirect 
happens after the loop finish. is there any plugin or method to do this?

my code
.....

    $c->res->redirect(' http://www.yahoo.com' <http://www.yahoo.com%27>);
    my $n;
    while($n<99999) {
        $c->log->debug($n);
        $n++;
    }
    $c->log->debug('asaaaaaaaaaaaa');
........  

of course. the while loop is faked. indeed it's something involved with $c.
the logic of Catalyst is run the whole sub over then call end. but I 
want to print redirect to visitor then run the while in backend.

is that clear enough?
Thanks for help.

-- 
Fayland Lam // http://www.fayland.org/