Problem with blocking

Hello,

I am using HTML::Parser to extract Hyperlinks from a Web Page. I wrote a 
Module MyParser wich is based on the above quoted Perl module.

Now I want to ensure, that the Parser finished his work before I query the 
links. I have a member function getHyperlinks which returns a hash containing 
the links. No big thing:

$p->parse;
my %links = $p->getHyperlinks;

I thougt that the parser may still parse, so I assigned a boolean variable 
$isParsing which is set to true by the start_document handler and set to 
false by the end_document handler.

sub getHyperlinks {
   my $self = shift;
   while($isParsing) { }
   return %{self->{HYPERLINKS}};
}

Actually the parser seems to be blocking now. What is the best way to ensure 
that the parser finished extracting all links without blocking the whole 
thing?

Best Regards,

Oliver