Re^3: Strange blocking issue with HTTP::Daemon

[Anonymous Monk]

in reply to Re^2: Strange blocking issue with HTTP::Daemon
in thread Strange blocking issue with HTTP::Daemon

Replying to an ancient post but this is little to do with HTTP::Daemon. The issue is that once you have accepted a connection you loop processing its requests until it goes away. With the LWP::UserAgent it appears to close the connection after each request but a web browser will attempt to keep the connection open meaning your code will block on the get_request.

The example code in the HTTP:Daemon synopsis is the problem. The code below is how I use HTTP::Daemon. Instead of blocking in the get_request call I put the daemon and client connections in an IO::Select object and block on that and only process data from those that are ready. That way a single threaded server can appear to be processing data concurrently from multiple connections including regular browsers that will keep the connection open.

  my $d = HTTP::Daemon->new(
    LocalAddr => 'localhost',
    LocalPort => 4242,
    ReuseAddr => 1) || die;
  my $select = IO::Select->new();
  $select->add($d);
  while ($select->count()) {
    my @ready = $select->can_read();  # Blocking
    foreach my $connection (@ready) {
      if ($connection == $d) {
        # on the daemon so accept and add the connection 
        my $client = $connection->accept();
        $select->add($client);
      }
      else {
        # is a client connection
        my $request = $connection->get_request();
        if ($request) {
          # process the request
        }
        else {
          # connection closed by the client
          $select->remove($connection);
          $connection->close();  # probably not necessary
        }
     } # end processing connections with data
   }

Now back to investigating the problem I was originally looking at. Why does get_request block on malformed / incomplete requests.......

[Anonymous Monk]

HTTP::Daemon::ClientConn::get_request blocks until it has a correct request because that's what it is documented to do.