@canBeRead = select->can_read(); 
foreach $elem (@canBeRead) { 
    $elem->getline();
}

##</code><code>##

$th1 = threads->create('foo',$firstFD);
$th2 = threads->create('foo',$secondFD);


sub foo {

  my $fh = shift;
  use the $fh to read from the file.
}