Megatest

;;               (ok-res . #t)))
;; 	      (vector #f res))
;;             (begin
;;               #;(common:telemetry-log (conc "api-out:"(->string cmd))
;;               payload: `((params . ,params)
;;               (ok-res . #f)))
;;               (vector #t res))))))))

(define *api-threads* '())
(define (api:register-thread th-in)
  (set! *api-threads* (cons (cons th-in (current-seconds)) *api-threads*)))

(define (api:unregister-thread th-in)
  (set! *api-threads* (filter (lambda (thdat)
				(not (eq? th-in (car thdat))))
			      *api-threads*)))

(define (api:remove-dead-or-terminated)
  (set! *api-threads* (filter (lambda (thdat)
				(not (member (thread-state (car thdat)) '(terminated dead))))
			      *api-threads*)))

(define (api:get-count-threads-alive)
  (length *api-threads*))
  

;; indat is (cmd run-id params meta)
;;
;; WARNING: Do not print anything in the lambda of this function as it
;;          reads/writes to current in/out port
;;
(define (api:tcp-dispatch-request-make-handler dbstruct) ;; cmd run-id params)
  (assert *toppath* "FATAL: api:tcp-dispatch-request-make-handler called but *toppath* not set.")
  (if (not *server-signature*)
      (set! *server-signature* (tt:mk-signature *toppath*)))
  (lambda (indat)
    (api:register-thread (current-thread))
    (let* (;; (indat      (deserialize))
	   (newcount   (+ *api-process-request-count* 1))
	   (numthreads (api:get-count-threads-alive))
	   (delay-wait (if (> newcount 10)
			   (- newcount 10)
			   0))
	   (normal-proc (lambda (cmd run-id params)
			  (case cmd
			    ((ping) *server-signature*)
			    (else
			     (api:dispatch-request dbstruct cmd run-id params))))))
      (set! *api-process-request-count* newcount)
      (set! *db-last-access* (current-seconds))
      (if (not (eq? newcount numthreads))
	  (begin
	    (api:remove-dead-or-terminated)
	    (let ((threads-now (api:get-count-threads-alive)))
	      (debug:print 0 *default-log-port* "WARNING: newcount="newcount", numthreads="numthreads", remaining="threads-now)
	      (set! newcount threads-now))))
      (match indat
	((cmd run-id params meta)
	 (let* ((db-ok  (let* ((dbfname (dbmod:run-id->dbfname run-id))
			       (ok      (equal? dbfname (dbr:dbstruct-dbfname dbstruct))))
			  (case cmd
			    ((ping) #t) ;; we are fine
			    (else

			   ((loaded) (conc "Server loaded, "newcount" threads in flight"))
			   (else     #f)))
		(result  (case status
			   ((busy)
			    (if (eq? cmd 'ping)
				(normal-proc cmd run-id params)
				;; newcount must be greater than 5 for busy
				(* 0.25 (- newcount 3)) ;; was 15
				(* 1 (- newcount 3)) ;; was 15
				)) ;; (- newcount 29)) ;; call back in as many seconds
			   ((loaded)
;; 			    (if (eq? (rmt:transport-mode) 'tcp)
;; 				(thread-sleep! 0.5))
			    (normal-proc cmd run-id params))
			   (else
			    (normal-proc cmd run-id params))))
		(meta   (case cmd
			  ((ping) `((sstate . ,server-state)))
			  (else   `((wait . ,delay-wait)))))
		(payload (list status errmsg result meta)))
	   (set! *api-process-request-count* (- *api-process-request-count* 1))
	   ;; (serialize payload)
	   (api:unregister-thread (current-thread))
	   payload))
	(else
	 (assert #f "FATAL: failed to deserialize indat "indat))))))
       

(define (api:dispatch-request dbstruct cmd run-id params)
  (if (not *no-sync-db*)

(define (dbfile:simple-file-release-lock fname)
  (handle-exceptions
      exn
      #f ;; I don't really care why this failed (at least for now)
    (delete-file* fname)))

(define (dbfile:with-simple-file-lock fname proc #!key (expire-time 300))
(define (dbfile:with-simple-file-lock fname proc #!key (expire-time 300)(run-anyway #f))
  (let ((start-time (current-seconds))
        (gotlock (dbfile:simple-file-lock-and-wait fname expire-time: expire-time))
        (end-time (current-seconds))
        )
    (if gotlock
	(let ((res (proc)))
	  (dbfile:simple-file-release-lock fname)
	  res)
        (begin
          (dbfile:print-err "dbfile:with-simple-file-lock: " fname " is locked by "
			    (with-input-from-file fname
			      (lambda ()
				(dbfile:print-err (read-line)))))
          (dbfile:print-err "wait time = " (- end-time start-time))
	  (dbfile:print-err "ERROR: simple file lock could not get a lock for " fname " in " expire-time " seconds")
          #f
        )
	  (if run-anyway
	      (let ((res (proc)))
    )
  )
)

		(dbfile:simple-file-release-lock fname)
		res)
	      #f)))))

(define *get-cache-stmth-mutex* (make-mutex))

(define (db:get-cache-stmth dbdat db stmt)
  (mutex-lock! *get-cache-stmth-mutex*)
  (let* (;; (dbdat       (dbfile:get-dbdat dbstruct run-id))
	 (stmt-cache  (dbr:dbdat-stmt-cache dbdat))

     (let* ((dbexists (file-exists? dbfullname))
	    (db       (sqlite3:open-database dbfullname))
	    (handler  (sqlite3:make-busy-timeout 136000)))
       (sqlite3:set-busy-handler! db handler)
       (if (and dbexists
		write-access)
	   (init-proc db))
       db))))
       db))
   run-anyway: #t))

(define *sync-in-progress* #f)

;; Open the cachedb db and the on-disk db
;; populate the cachedb db with data
;;
;; Updates fields in dbstruct