Megatest

(define  *server-loop-heart-beat* (current-seconds))
(define *heartbeat-mutex* (make-mutex))

(define (server:self-ping iface port)
  (let ((zsocket (server:client-connect iface port)))
    (let loop ()
      (thread-sleep! 2)
      (cdb:client-call zsocket 'ping #t)
      (debug:print 4 "server:self-ping - I'm alive on " iface ":" port "!")
      (mutex-lock! *heartbeat-mutex*)
      (set! *server-loop-heart-beat* (current-seconds))
      (mutex-unlock! *heartbeat-mutex*)
      (loop))))
    

;; run server:keep-running in a parallel thread to monitor that the db is being 
;; used and to shutdown after sometime if it is not.
;;
(define (server:keep-running)
  ;; if none running or if > 20 seconds since 
  ;; server last used then start shutdown
  (let loop ((count 0))
    (thread-sleep! 4) ;; no need to do this very often
    (db:write-cached-data)
    ;; (print "Server running, count is " count)
    (if (< count 1) ;; 3x3 = 9 secs aprox
	(loop (+ count 1))
	(let (;; (numrunning            (open-run-close db:get-count-tests-running #f))
	      (server-loop-heartbeat #f)
	      (server-info           #f)
	      (pulse                 0))
	  ;; BUG add a wait on server alive here!!
	  ;; ;; Ugly yuk. 
	  (mutex-lock! *heartbeat-mutex*)
	  (set! server-loop-heartbeat *server-loop-heart-beat*)
	  (set! server-info *server-info*)
	  (mutex-unlock! *heartbeat-mutex*)
	  ;; The logic here is that if the server loop gets stuck blocked in working
	  ;; we don't want to update our heartbeat
	  (set! pulse (- (current-seconds) server-loop-heartbeat))
	  (debug:print-info 1 "Heartbeat period is " pulse " seconds on " (cadr server-info) ":" (caddr server-info) ", last db access is " (- (current-seconds) *last-db-access*) " seconds ago")
	  (if (> pulse 15) ;; must stay less than 10 seconds 
	      (begin
		(open-run-close tasks:server-deregister tasks:open-db (cadr server-info) port: (caddr server-info))
		(debug:print 0 "ERROR: Heartbeat failed, committing servercide")
		(exit))
	      (open-run-close tasks:server-update-heartbeat tasks:open-db (car server-info)))
	  ;; (if ;; (or (> numrunning 0) ;; stay alive for two days after last access
	  (if (> (+ *last-db-access* 
		    ;; (* 48 60 60)    ;; 48 hrs
		    ;; 60              ;; one minute
		    (* 60 60)       ;; one hour
		    )
		 (current-seconds))
	      (begin
		;; (debug:print-info 2 "Server continuing, tests running: " numrunning ", seconds since last db access: " (- (current-seconds) *last-db-access*))
		(debug:print-info 2 "Server continuing, seconds since last db access: " (- (current-seconds) *last-db-access*))
		(loop 0))
	      (begin
		(debug:print-info 0 "Starting to shutdown the server.")
		;; need to delete only *my* server entry (future use)
		(set! *time-to-exit* #t)
		(open-run-close tasks:server-deregister-self tasks:open-db (get-host-name))
		(thread-sleep! 1)

	(debug:print-info 1 "NOT starting new server, one is already running on " (car hostinfo) ":" (cadr hostinfo))
	(if *toppath* 
	    (let* ((th1 (make-thread (lambda ()
				       (let ((server-info #f))
					 ;; wait for the server to be online and available
					 (let loop ()
					   (debug:print-info 1 "Waiting for the server to come online before starting heartbeat")
					   (thread-sleep! 2)
					   (mutex-lock! *heartbeat-mutex*)
					   (set! server-info *server-info* )
					   (mutex-unlock! *heartbeat-mutex*)
					   (if (not server-info)(loop)))
					 (debug:print 1 "Server alive, starting self-ping")
					 (server:self-ping (cadr server-info)(caddr server-info)))) "Self ping"))
		   (th2 (make-thread (lambda ()
				       (server:run (args:get-arg "-server"))) "Server run"))
		   (th3 (make-thread (lambda ()
				       (server:keep-running)) "Keep running")))
	      (set! *client-non-blocking-mode* #t)
	      (thread-start! th1)
	      (thread-start! th2)
	      (thread-start! th3)
	      (set! *didsomething* #t)
	      (thread-join! th3))
	    (debug:print 0 "ERROR: Failed to setup for megatest")))
    (exit)))

(define (server:client-launch #!key (do-ping #f))
  (if (server:client-setup)
      (debug:print-info 2 "connected as client")
      (begin
	(debug:print 0 "ERROR: Failed to connect as client")
	(exit))))

;; ping a server and return number of clients or #f (if no response)
(define (server:ping host port #!key (secs 10)(return-socket #f))

(define (tasks:open-db)
  (let* ((dbpath  (conc *toppath* "/monitor.db"))
	 (exists  (file-exists? dbpath))
	 (mdb     (sqlite3:open-database dbpath)) ;; (never-give-up-open-db dbpath))
	 (handler (make-busy-timeout 36000)))
    (sqlite3:set-busy-handler! mdb handler)
    (sqlite3:execute mdb (conc "PRAGMA synchronous = 0;"))
    (if (not exists)
	(begin
	  (sqlite3:execute mdb "CREATE TABLE IF NOT EXISTS tasks_queue (id INTEGER PRIMARY KEY,
                                action TEXT DEFAULT '',
                                owner TEXT,
                                state TEXT DEFAULT 'new',
                                target TEXT DEFAULT '',

		      (loop (car tal)(cdr tal))))))))))

(define (tasks:kill-server status hostname port pid)
  (debug:print-info 1 "Removing defunct server record for " hostname ":" port)
  (if port
      (open-run-close tasks:server-deregister tasks:open-db hostname port: port)
      (open-run-close tasks:server-deregister tasks:open-db hostname pid:  pid))

  (if status ;; #t means alive
      (begin
	(if (equal? hostname (get-host-name))
	    (handle-exceptions
	     exn
	     (debug:print-info 0 "server may or may not be dead, check for megatest -server running as pid " pid "\n"
			       "  EXCEPTION: " ((condition-property-accessor 'exn 'message) exn))