From tom.weissmann at gmail.com  Fri Jun 26 09:52:59 2009
From: tom.weissmann at gmail.com (Tom Weissmann)
Date: Fri, 26 Jun 2009 11:52:59 +0200
Subject: [kpax-devel] Error stopping server with mod-lisp and SBCL
Message-ID: <6b1460640906260252j27bf7c15jee0584da9d255eef@mail.gmail.com>

Hi,

Whilst experimenting with the KPAX examples and sbcl I experienced
errors trying to stop the server:

(stop-kpax) produces the error:

The value
  (("mod-lisp server port 2001"
    #<SB-BSD-SOCKETS:INET-SOCKET descriptor 5 {BDE4661}>
    #<SB-IMPL::HANDLER INPUT on descriptor 5: #>))
is not of type
  SB-THREAD:THREAD.

Looking into it can't understand how would ever work:

- The server's applicable startup method sets it server-process slot
to the result of calling s-sysdeps:start-standard-server.

- With sbcl, s-sysdeps:start-standard-server returns the result of
(push (list name
                            socket
                            (sb-sys:add-fd-handler
                             (sb-bsd-sockets:socket-file-descriptor socket)
                             :input handler-fn))
                      *server-processes*)
... this looks highly suspect

- The server's applicable shutdown method tries to call
s-sysdeps:kill-process on this.

- With sbcl, s-sysdeps:kill-process uses sb-thread:terminate-thread,
which doesn't expect a list of lists.

---
 The following ugly hack in mod-lisp.lisp fixes the immediate problem
but not much else:

(defmethod shutdown ((web-app-server mod-lisp-server) &optional options)
  (destructuring-bind (&key (graceful t) &allow-other-keys)
      options
    (declare (ignore graceful))
    (with-slots (server-process client-processes)
        web-app-server
      (dolist (process client-processes) ;; these should be removed
when unwinding
        (s-sysdeps:kill-process process))
      (setf client-processes nil)
      (when server-process
        #+sb-thread (dolist (proc-info server-process)
                      (s-sysdeps::stop-server (first proc-info)))
        #-sb-thread (s-sysdeps:kill-process server-process)
        (setf server-process nil)))
    (call-next-method))
  web-app-server)

Regards,
Tom SW