make-time-segment time-segment?
time-segment-time time-segment-queue
- time-< time-= time-<= time-+
+ time< time= time<= time-delta+
+ time-minus time-plus
<time-delta>
make-time-delta tdelta time-delta?
make-run-request run-request?
run-request-proc run-request-when
- run wrap run-wrap run-wrap-at
+ run-it wrap run run-at delay
%current-agenda
start-agenda agenda-run-once))
(queue time-segment-queue))
(define (time-segment-right-format time)
+ "Ensure TIME is in the right format.
+
+The right format means (second . microsecond).
+If an integer, will convert appropriately."
+ ;; TODO: add floating point / rational number support.
(match time
;; time is already a cons of second and microsecnd
(((? integer? s) . (? integer? u)) time)
(_ (throw 'invalid-time "Invalid time" time))))
(define* (make-time-segment time #:optional (queue (make-q)))
+ "Make a time segment of TIME and QUEUE
+
+No automatic conversion is done, so you might have to
+run (time-segment-right-format) first."
(make-time-segment-intern time queue))
-(define (time-< time1 time2)
+(define (time< time1 time2)
+ "Check if TIME1 is less than TIME2"
(cond ((< (car time1)
(car time2))
#t)
#t)
(else #f)))
-(define (time-= time1 time2)
+(define (time= time1 time2)
+ "Check whether TIME1 and TIME2 are equivalent"
(and (= (car time1) (car time2))
(= (cdr time1) (cdr time2))))
-(define (time-<= time1 time2)
- (or (time-< time1 time2)
- (time-= time1 time2)))
+(define (time<= time1 time2)
+ "Check if TIME1 is less than or equal to TIME2"
+ (or (time< time1 time2)
+ (time= time1 time2)))
(define-record-type <time-delta>
(usec time-delta-usec))
(define* (make-time-delta sec #:optional usec)
+ "Make a <time-delta> of SEC seconds and USEC microseconds.
+
+This is used primarily so the agenda can recognize RUN-REQUEST objects
+which are meant "
(make-time-delta-intern sec (or usec 0)))
(define tdelta make-time-delta)
-(define (time-+ time time-delta)
- (cons (+ (car time) (time-delta-sec time-delta))
- (+ (cdr time) (time-delta-usec time-delta))))
+(define (time-carry-correct time)
+ "Corrects/handles time microsecond carry.
+Will produce (0 . 0) instead of a negative number, if needed."
+ (cond ((>= (cdr time) 1000000)
+ (cons
+ (+ (car time) 1)
+ (- (cdr time) 1000000)))
+ ((< (cdr time) 0)
+ (if (= (car time) 0)
+ '(0 0)
+ (cons
+ (- (car time) 1)
+ (+ (cdr time) 1000000))))
+ (else time)))
+
+(define (time-delta+ time time-delta)
+ "Increment a TIME by the value of TIME-DELTA"
+ (time-carry-correct
+ (cons (+ (car time) (time-delta-sec time-delta))
+ (+ (cdr time) (time-delta-usec time-delta)))))
+
+(define (time-minus time1 time2)
+ "Subtract TIME2 from TIME1"
+ (time-carry-correct
+ (cons (- (car time1) (car time2))
+ (- (cdr time2) (cdr time2)))))
+
+(define (time-plus time1 time2)
+ "Add TIME1 and TIME2"
+ (time-carry-correct
+ (cons (+ (car time1) (car time2))
+ (+ (cdr time2) (cdr time2)))))
(define-record-type <schedule>
(segments schedule-segments set-schedule-segments!))
(define* (make-schedule #:optional segments)
+ "Make a schedule, optionally pre-composed of SEGMENTS"
(make-schedule-intern (or segments '())))
(define (schedule-soonest-time schedule)
;; but at least it'll be reasonably easy to refactor to
;; a more functional setup?
(define (schedule-add! schedule time proc)
+ "Mutate SCHEDULE, adding PROC at an appropriate time segment for TIME"
(let ((time (time-segment-right-format time)))
(define (new-time-segment)
(let ((new-segment
new-segment))
(define (loop segments)
(define (segment-equals-time? segment)
- (time-= time (time-segment-time segment)))
+ (time= time (time-segment-time segment)))
(define (segment-more-than-time? segment)
- (time-< time (time-segment-time segment)))
+ (time< time (time-segment-time segment)))
;; We could switch this out to be more mutate'y
;; and avoid the O(n) of space... is that over-optimizing?
(loop (schedule-segments schedule)))))
(define (schedule-empty? schedule)
+ "Check if the SCHEDULE is currently empty"
(eq? (schedule-segments schedule) '()))
(define (schedule-segments-split schedule time)
"Does a multiple value return of time segments before/at and after TIME"
(let ((time (time-segment-right-format time)))
(define (segment-is-now? segment)
- (time-= (time-segment-time segment) time))
+ (time= (time-segment-time segment) time))
(define (segment-is-before-now? segment)
- (time-< (time-segment-time segment) time))
+ (time< (time-segment-time segment) time))
(let loop ((segments-before '())
(segments-left (schedule-segments schedule)))
;;; Request to run stuff
;;; ====================
-(define-record-type <run-request>
+(define-immutable-record-type <run-request>
(make-run-request proc when)
run-request?
(proc run-request-proc)
(when run-request-when))
-(define* (run proc #:optional when)
+(define* (run-it proc #:optional when)
+ "Make a request to run PROC (possibly at WHEN)"
(make-run-request proc when))
(define-syntax-rule (wrap body ...)
+ "Wrap contents in a procedure"
(lambda ()
body ...))
-(define-syntax-rule (run-wrap body ...)
- (run (wrap body ...)))
+(define-syntax-rule (run body ...)
+ "Run everything in BODY but wrap in a convenient procedure"
+ (make-run-request (wrap body ...) #f))
+
+(define-syntax-rule (run-at body ... when)
+ "Run BODY at WHEN"
+ (make-run-request (wrap body ...) when))
+
+(define-syntax-rule (run-delay body ... delay-time)
+ "Run BODY at DELAY-TIME time from now"
+ (make-run-request (wrap body ...) (tdelta delay-time)))
-(define-syntax-rule (run-wrap-at body ... when)
- (run (wrap body ...) when))
+(define (delay run-request delay-time)
+ "Delay a RUN-REQUEST by DELAY-TIME"
+ (set-field run-request
+ (run-request-when)
+ (tdelta delay-time)))
\f
;;; Execution of agenda, and current agenda
(define %current-agenda (make-parameter #f))
(define (update-agenda-from-select! agenda)
- (define (hash-keys selector)
+ (define (hash-keys hash)
(hash-map->list (lambda (k v) k) hash))
(define (get-wait-time)
;; TODO: we need to figure this out based on whether there's anything
(let ((soonest-time (schedule-soonest-time (agenda-schedule agenda))))
(cond
((not (q-empty? (agenda-queue agenda)))
- (values 0 0))
+ (cons 0 0))
(soonest-time ; ie, the agenda is non-empty
(let* ((current-time (agenda-time agenda)))
- (if (time-<= soonest-time current-time)
+ (if (time<= soonest-time current-time)
;; Well there's something due so let's select
;; (this avoids a (possible?) race condition chance)
- (values 0 0)
- (values
- (- (car soonest-time) (car current-time))
- (- (cdr soonest-time) (cdr current-time))))))
+ (cons 0 0)
+ (time-minus soonest-time current-time))))
(else
- (values #f #f)))))
+ (cons #f #f)))))
(define (do-select)
;; TODO: support usecond wait time too
- (receive (sec usec)
- (get-wait-time)
- (select (hash-keys (agenda-read-port-map agenda))
- (hash-keys (agenda-write-port-map agenda))
- (hash-keys (agenda-except-port-map agenda))
- sec usec)))
+ (match (get-wait-time)
+ ((sec . usec)
+ (select (hash-keys (agenda-read-port-map agenda))
+ (hash-keys (agenda-write-port-map agenda))
+ (hash-keys (agenda-except-port-map agenda))
+ sec usec))))
(define (get-procs-to-run)
(define (ports->procs ports port-map)
(lambda (initial-procs)
(agenda-run-once agenda))))
(if (and stop-condition (stop-condition agenda))
'done
- (let* ((new-time (get-time))
- (agenda
- (handle-ports
- ;; 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))))
+ (let* ((agenda
+ ;; We have to update the time after ports handled, too
+ ;; because it may have changed after a select
+ (set-field
+ (handle-ports
+ ;; 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) (get-time)))
+ (agenda-time) (get-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)
+ (schedule-extract-until! (agenda-schedule agenda) (agenda-time agenda))
(agenda-queue agenda))
(loop agenda))))))
(let ((request-time (run-request-when run-request)))
(match request-time
((? time-delta? time-delta)
- (let ((time (time-+ (agenda-time agenda)
- time-delta)))
+ (let ((time (time-delta+ (agenda-time agenda)
+ time-delta)))
(schedule-at! time (run-request-proc run-request))))
((? integer? sec)
(let ((time (cons sec 0)))