make-time-segment time-segment?
time-segment-time time-segment-queue
- time-< time-= time-<=
+ time-< time-= time-<= time-+
+
+ <time-delta>
+ make-time-delta time-delta?
+ time-delta-sec time-delta-usec
<schedule>
make-schedule schedule?
;;; This is where we handle timed events for the future
-;; This section totally borrows from SICP
+;; This section totally borrows from the ideas in SICP
;; <3 <3 <3
;; NOTE: time is a cons of (seconds . microseconds)
(or (time-< time1 time2)
(time-= time1 time2)))
+
+(define-record-type <time-delta>
+ (make-time-delta-intern sec usec)
+ time-delta?
+ (sec time-delta-sec)
+ (usec time-delta-usec))
+
+(define* (make-time-delta sec #:optional usec)
+ (make-time-delta-intern sec (or usec 0)))
+
+(define (time-+ time time-delta)
+ (cons (+ (car time) (time-delta-sec time-delta))
+ (+ (cdr time) (time-delta-usec time-delta))))
+
+
(define-record-type <schedule>
(make-schedule-intern segments)
schedule?
;; mutates AND is worst case of O(n) in both space and time :(
;; but at least it'll be reasonably easy to refactor to
;; a more functional setup?
-(define (schedule-add! time proc schedule)
+(define (schedule-add! schedule time proc)
(let ((time (time-segment-right-format time)))
(define (new-time-segment)
(let ((new-segment
(define* (start-agenda agenda #:optional stop-condition)
(let loop ((agenda agenda))
- (let ((new-agenda
+ (let ((agenda
;; @@: Hm, maybe here would be a great place to handle
;; select'ing on ports.
;; We could compose over agenda-run-once and agenda-read-ports
(agenda-run-once agenda))))
(if (and stop-condition (stop-condition agenda))
'done
- (loop
- ;; Adjust the agenda's time just in time
- ;; We do this here rather than in agenda-run-once to make
- ;; agenda-run-once's behavior fairly predictable
- (set-field new-agenda (agenda-time) (gettimeofday)))))))
+ (let* ((new-time (gettimeofday))
+ (agenda
+ ;; Adjust the agenda's time just in time
+ ;; We do this here rather than in agenda-run-once to make
+ ;; agenda-run-once's behavior fairly predictable
+ (set-field agenda (agenda-time) new-time)))
+ ;; Update the agenda's current queue based on
+ ;; currently applicable time segments
+ (add-segments-contents-to-queue!
+ (schedule-extract-until! (agenda-schedule agenda) new-time)
+ (agenda-queue agenda))
+ (loop agenda))))))
(define (agenda-run-once agenda)
"Run once through the agenda, and produce a new agenda
(proc-result (call-proc proc))
(enqueue
(lambda (run-request)
- (cond
- ((run-request-when run-request)
- (error "TODO"))
- (else
- (enq! next-queue (run-request-proc run-request)))))))
+ (define (schedule-at! time proc)
+ (schedule-add! (agenda-schedule agenda) time proc))
+ (let ((request-time (run-request-when run-request)))
+ (match request-time
+ ((? time-delta? time-delta)
+ (let ((time (time-+ (agenda-time agenda)
+ time-delta)))
+ (schedule-at! time (run-request-proc run-request))))
+ ((? integer? sec)
+ (let ((time (cons sec 0)))
+ (schedule-at! time (run-request-proc run-request))))
+ (((? integer? sec) . (? integer? usec))
+ (schedule-at! request-time (run-request-proc run-request)))
+ (#f
+ (enq! next-queue (run-request-proc run-request))))))))
;; @@: We might support delay-wrapped procedures here
(match proc-result
;; TODO: replace procedure with something that indicates
new-procs))
;; do nothing
(_ #f))))
- ;; TODO: Selecting on ports would happen here?
+ ;; TODO: Alternately, we could return the next-queue
+ ;; along with changes to be added to the schedule here?
;; Return new agenda, with next queue set
(set-field agenda (agenda-queue) next-queue)))