Megatest

         (begin
           (apply (eval procsym) params))))
    res))


;; rpc receiver
(define (rpc-transport:api-exec cmd params)
  (let* ( (resdat  (api:execute-requests *inmemdb* (vector cmd params))) ;; #( flag result )
          (flag    (vector-ref resdat 0))
          (res     (vector-ref resdat 1)))

    (mutex-lock! *heartbeat-mutex*)

    (set! *last-db-access* (current-seconds)) ;; bump *last-db-access*; this will renew keep-running thread's lease on life for another (server:get-timeout) seconds
    ;;(BB> "in api-exec; last-db-access updated to "*last-db-access*)

  ;;(tasks:server-set-state! (db:delay-if-busy (tasks:open-db)) server-id "stopped")


  ;; TODO: (low) the following is extraordinaritly slow.  Maybe we don't even need portlogger for rpc anyway??  the exception-based failover when ports are taken is fast!
  ;;(portlogger:open-run-close portlogger:set-port (rpc:default-server-port) "released")
  
  (set! *time-to-exit* #t)
  ;;(if *inmemdb* (db:sync-touched *inmemdb* *run-id* force-sync: #t))


  (tasks:server-delete-record (db:delay-if-busy (tasks:open-db)) server-id " rpc-transport:keep-running complete")
  

  ;;(BB> "Before (exit) (from-on-exit="from-on-exit")")
  ;;(unless from-on-exit (exit))  ;; sometimes we hang (around) here with 100% cpu.
  ;;(BB> "After")
  ;; strace reveals endless:

  ;; (when (args:get-arg "-daemonize")
  ;;     (daemon:ize)
  ;;     (when *alt-log-file* ;; we should re-connect to this port, I think daemon:ize disrupts it
  ;;       (current-error-port *alt-log-file*)
  ;;       (current-output-port *alt-log-file*)))

  ;; double check we dont alrady have a running server for this run-id

  (when (server:check-if-running run-id)
    (debug:print 0 *default-log-port* "INFO: Server for run-id " run-id " already running")
    (exit 0))


  ;; clean up dead servers (duped in megatest.scm in -list-servers processing; may want to consolidate into proc)
  (for-each
   (lambda (server)
     (let* ((id         (vector-ref server 0))
            (pid        (vector-ref server 1))
            (hostname   (vector-ref server 2))
            (interface  (vector-ref server 3)) 
            (pullport   (vector-ref server 4))
            (pubport    (vector-ref server 5))
            (start-time (vector-ref server 6))
            (priority   (vector-ref server 7))
            (state      (vector-ref server 8))
            (mt-ver     (vector-ref server 9))
            (last-update (vector-ref server 10)) 
            (transport  (vector-ref server 11))
            (killed     #f)
            (status     (< last-update 20)))

       (if (equal? state "dead")
           (if (> last-update (* 25 60 60)) ;; keep records around for slighly over a day.
               (tasks:server-deregister (db:delay-if-busy (tasks:open-db)) hostname pullport: pullport pid: pid action: 'delete))
           (if (> last-update 20)        ;; Mark as dead if not updated in last 20 seconds
               (tasks:server-deregister (db:delay-if-busy (tasks:open-db)) hostname pullport: pullport pid: pid)))
       ;;(format #t fmtstr id mt-ver pid hostname (conc interface ":" pullport) pubport last-update
       ;;        (if status "alive" "dead") transport)
       ;; (if (or (equal? id sid)
       ;;         (equal? sid 0)) ;; kill all/any
       ;;     (begin
       ;;       (debug:print-info 0 *default-log-port* "Attempting to kill "kill-switch" server with pid " pid)
       ;;       (tasks:kill-server hostname pid kill-switch: kill-switch)))

       )
       
     )
   (tasks:get-all-servers (db:delay-if-busy (tasks:open-db))))
   
  ;; let's get a server-id for this server
  ;;   if at first we do not suceed, try 3 more times.
  (let ((server-id (retry-thunk
                    (lambda () (tasks:server-lock-slot (db:delay-if-busy (tasks:open-db)) run-id 'rpc))
                    chatty: #f
                    final-failure-returns-actual: #t
                    retries: 4)))
    (when (not server-id) ;; dang we couldn't get a server-id.
      ;; since we didn't get the server lock we are going to clean up and bail out


      (debug:print-info 2 *default-log-port* "INFO: server pid=" (current-process-id) ", hostname=" (get-host-name) " not starting due to other candidates ahead in start queue")
      (tasks:server-delete-records-for-this-pid (db:delay-if-busy (tasks:open-db)) " rpc-transport:launch")

      (exit 1))

    ;; we got a server-id (and a corresponding entry in servers table in globally shared mdb)
    ;; all systems go.  Proceed to setup rpc server.  
    (rpc-transport:run
     (if (args:get-arg "-server")
         (args:get-arg "-server")

         ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
         ;; rpc:listener is the tcp-listen result from inside the find-free-port-and-open complex.
         ;;   It is our handle on the listening tcp port
         ;;   We will attach this to our rpc server with rpc:make-server in thread th1 .
	 (rpc:listener    (rpc-transport:find-free-port-and-open start-port)) 
	 (th1             (make-thread
			   (lambda ()

			     ((rpc:make-server rpc:listener) #t) )


			   "rpc:server"))


         (hostname        (if (string=? "-" hostn)
			      (get-host-name) 
			      hostn))
	 (ipaddrstr       (if (string=? "-" hostn)
			      (server:get-best-guess-address hostname) ;; (string-intersperse (map number->string (u8vector->list (hostname->ip hostname))) ".")
                              (string-intersperse 
                               (map number->string
                                    (u8vector->list
                                      (hostname->ip hostn))) ".")
                              ))
	 (portnum         (let ((res (rpc:default-server-port)))  res))
	 (host:port       (conc (if ipaddrstr ipaddrstr hostname) ":" portnum)))








    (tasks:server-set-interface-port (db:delay-if-busy (tasks:open-db)) server-id ipaddrstr portnum)

    ;;============================================================
    ;;  activate thread th1 to attach opened tcp port to rpc server
    ;;=============================================================
    (thread-start! th1)
    (set! db *inmemdb*)

    (debug:print 0 *default-log-port* "Server started on " host:port)

    ;; (thread-sleep! 5)

    (if (retry-thunk (lambda ()
                       (rpc-transport:self-test run-id ipaddrstr portnum))
                     final-failure-returns-actual: #t
                     )
        (debug:print 0 *default-log-port* "INFO: rpc self test passed!")
        (begin
          (debug:print 0 *default-log-port* "Error: rpc listener did not pass self test.  Shutting down.  On: " host:port)
          (tasks:server-set-state! (db:delay-if-busy (tasks:open-db)) server-id "dead")
          (tcp-close rpc:listener) ;; gotta exit nicely and free up that tcp port
          (rpc-transport:server-shutdown server-id rpc:listener)

          (exit)))
    (mutex-lock! *heartbeat-mutex*)
    (set! *last-db-access* (current-seconds))
    (mutex-unlock! *heartbeat-mutex*)

    ;;(on-exit (lambda ()
    ;;           (rpc-transport:server-shutdown server-id rpc:listener from-on-exit: #t)))
    
    ;; check again for running servers for this run-id in case one has snuck in since we checked last in rpc-transport:launch
    (if (not (equal? server-id (tasks:server-am-i-the-server? (db:delay-if-busy (tasks:open-db)) run-id)));; try to ensure no double registering of servers
        (begin ;; i am not the server, another server snuck in and beat this one to the punch
          (tcp-close rpc:listener) ;; gotta exit nicely and free up that tcp port
          (tasks:server-set-state! (db:delay-if-busy (tasks:open-db)) server-id "collision"))


        (begin ;; i am the server
          ;; setup the in-memory db
          (set! *inmemdb*  (db:setup run-id))
          (db:get-db *inmemdb* run-id)


          ;; let's make it official




          (set! *rpc:listener* rpc:listener) 
          (tasks:server-set-state! (db:delay-if-busy (tasks:open-db)) server-id "running") ;; update our mdb servers entry

          
          
          ;; this let loop will hold open this thread until we want the server to shut down.
          ;;   if no requests received within the last 20 seconds :
          ;;   database hasnt changed in ??
          ;;

          ;; begin new loop

          ;; keep-running loop: polls last-db-access to see if we have timed out.  
          (let loop ((count          0)
                     (bad-sync-count 0))

            ;; Use this opportunity to sync the inmemdb to db

            (let ((start-time (current-milliseconds))
                  (sync-time  #f)
                  (rem-time   #f))


              ;; inmemdb is a dbstruct
              (condition-case
               (db:sync-touched *inmemdb* *run-id* force-sync: #t)
               ((sync-failed)(cond
                              ((> bad-sync-count 10) ;; time to give up
                               (rpc-transport:server-shutdown server-id rpc:listener))
                              (else ;; (> bad-sync-count 0)  ;; we've had a fail or two, delay and loop
                               (thread-sleep! 5)
                               (loop count (+ bad-sync-count 1)))))
               ((exn)
                (debug:print-error 0 *default-log-port* "error from sync code other than 'sync-failed. Attempting to gracefully shutdown the server")
                (rpc-transport:server-shutdown server-id rpc:listener)))

              (set! sync-time  (- (current-milliseconds) start-time))
              (set! rem-time (quotient (- 4000 sync-time) 1000))
              (debug:print 4 *default-log-port* "SYNC: time= " sync-time ", rem-time=" rem-time)
              
              (if (and (<= rem-time 4)
                       (> rem-time 0))
                  (thread-sleep! rem-time)

                    ;;
                    (if (tasks:server-am-i-the-server? (db:delay-if-busy (tasks:open-db)) run-id)
                        (tasks:server-set-state! (db:delay-if-busy (tasks:open-db)) server-id "running"))
                    ;;
                    (loop 0 bad-sync-count))
                  (begin
                    ;;(BB> "SERVER SHUTDOWN CALLED!  last-access="last-access" current-seconds="(current-seconds)" server-timeout="server-timeout)

                    (rpc-transport:server-shutdown server-id rpc:listener)))))
          ;; end new loop
          ))))


(define (rpc-transport:find-free-port-and-open port #!key )
  (handle-exceptions