Megatest

	  (print "ERROR: Communication failed?")
	  #f)))) ;; #f means failed to communicate

;;======================================================================
;; responder side
;;======================================================================

;; take a request, rdat, and if not immediate put it in the work queue
;;
;; Reserved cmds; ack ping goodbye response
;;
(define (ulex-handler uconn rdat)
  (match rdat ;;  (string-split controldat)
    ((rem-host-port qrykey cmd params)
     ;; (print "ulex-handler got: "rem-host-port" qrykey: "qrykey" cmd: "cmd" params: "params)
     (let ((mbox (hash-table-ref/default (udat-mboxes uconn) qrykey #f)))
       (case cmd
	 ;; ((ack )(print "Got ack! But why? Should NOT get here.") 'ack)
	 ((ping)
	  ;; (print "Got Ping!")
	  (add-to-work-queue uconn rdat)
	 'ack)
	 ((goodbye)
	  ;; just clear out references to the caller
	  (add-to-work-queue uconn rdat)
	  'ack)
	 ((response) ;; this is a result from remote processing, send it as mail ...
	  (if mbox
	      (begin
		(mailbox-send! mbox params) ;; params here is our result
		'ack)
	      (begin
		(print "ERROR: received result but no associated mbox for cookie "qrykey)
		#f)))
	 (else
	  ;; (print "Got generic request: "cmd)
	  (add-to-work-queue uconn rdat)
	  'ack))))
    (else
     (print "BAD DATA? controldat=" rdat)
     'ack) ;; send ack anyway?
    ))

;; given an already set up uconn start the cmd-loop
;;
(define (ulex-cmd-loop uconn)
  (let* ((serv-listener (udat-socket uconn)))
    (let loop ((state 'start))
      (let-values (((inp oup)(tcp-accept serv-listener)))
	(let* ((rdat  (read inp)) ;; '(my-host-port qrykey cmd params)
	       (resp  (ulex-handler uconn rdat)))
	  (if resp (write resp oup))
	  (close-input-port inp)
	  (close-output-port oup))
	(loop state)))))

;; add a proc to the cmd list, these are done symetrically (i.e. in all instances)
;; so that the proc can be dereferenced remotely
;;
(define (set-work-handler uconn proc)
  (udat-work-proc-set! uconn proc))

;;======================================================================
;; work queues - this is all happening on the listener side
;;======================================================================

;; rdat is (rem-host-port qrykey cmd params)
					     
(define (add-to-work-queue uconn rdat)
  (queue-add! (udat-work-queue uconn) rdat))

(define (do-work uconn rdat)
  (let* ((proc (udat-work-proc uconn))) ;; get it each time - conceivebly it could change
    ;; put this following into a do-work procedure
    (match rdat
      ((rem-host-port qrykey cmd params)
       (let* ((result (proc rem-host-port qrykey cmd params)))
	 ;; send 'response as cmd and result as params
	 (send uconn rem-host-port qrykey 'response result))) ;; could check for ack
      (else
       (print "ERROR: rdat "rdat", did not match rem-host-port qrykey cmd params")))))
     
     
(define (process-work-queue uconn) 
  (let ((wqueue (udat-work-queue uconn))
	(proc   (udat-work-proc  uconn)))
    (let loop ()
      (if (queue-empty? wqueue)
	  (thread-sleep! 0.1)
	  (let ((rdat (queue-remove! wqueue)))
	    (do-work uconn rdat)))
      (loop))))

;; below was to enable re-use of connections. This seems non-trivial so for
;; now lets open on each call
;;
;; ;; given host-port get or create peer struct
;; ;;