my $rb = $ssl->read(16384);
ssl_check_die("SSL read");
if(undefined($rb) or length($rb) <= 0){
  unless($! eq "Resource temporarily unavailable"){
    ## Here we are done - do whatever is necessary to
    ## shutdown select dispatcher and close sockets, release
    ## ssl and context
  }
  if($rb){
    ## you have read some data in $rb -- do something with it
  }
}