add true-after-n-times to tests file

[8sync.git] / loopy.scm

diff --git a/loopy.scm b/loopy.scm
index 261e14db704d9323f2ceab82b3a989359e12da7d..2f733c01d4fe32afa21641bc456c37efc4f0f171 100644 (file)
--- a/loopy.scm
+++ b/loopy.scm
@@ -4,20 +4,25 @@
   #:use-module (ice-9 q)
   #:use-module (ice-9 match)
   #:use-module (ice-9 receive)
-  #:export (make-agenda
-            agenda?
+  #:export (<agenda>
+            make-agenda agenda?
             agenda-queue agenda-prompt-tag
             agenda-port-pmapping agenda-schedule
             
             make-async-prompt-tag
 
-            make-time-segment
-            time-segment?
+            <time-segment>
+            make-time-segment time-segment?
             time-segment-time time-segment-queue
 
-            time-< time-= time-<=
+            time-< time-= time-<= time-+
 
-            make-schedule
+            <time-delta>
+            make-time-delta time-delta?
+            time-delta-sec time-delta-usec
+
+            <schedule>
+            make-schedule schedule?
             schedule-add! schedule-empty?
             schedule-segments
 
@@ -28,6 +33,12 @@
             port-mapping-set! port-mapping-remove!
             port-mapping-empty? port-mapping-non-empty?
 
+            <run-request>
+            make-run-request run-request?
+            run-request-proc run-request-when
+
+            run wrap run-wrap run-wrap-at
+
             %current-agenda
             start-agenda agenda-run-once))
 
@@ -53,12 +64,13 @@
 ;;;    and with reasonable separation from functional components?
 
 (define-immutable-record-type <agenda>
-  (make-agenda-intern queue prompt-tag port-mapping schedule)
+  (make-agenda-intern queue prompt-tag port-mapping schedule time)
   agenda?
   (queue agenda-queue)
   (prompt-tag agenda-prompt-tag)
   (port-mapping agenda-port-mapping)
-  (schedule agenda-schedule))
+  (schedule agenda-schedule)
+  (time agenda-time))
 
 (define (make-async-prompt-tag)
   (make-prompt-tag "prompt"))
@@ -67,8 +79,9 @@
                       (queue (make-q))
                       (prompt (make-prompt-tag))
                       (port-mapping (make-port-mapping))
-                      (schedule (make-schedule)))
-  (make-agenda-intern queue prompt port-mapping schedule))
+                      (schedule (make-schedule))
+                      (time (gettimeofday)))
+  (make-agenda-intern queue prompt port-mapping schedule time))
 
 
 \f
@@ -77,7 +90,7 @@
 
 ;;; 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)
@@ -118,6 +131,21 @@
   (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?
@@ -130,7 +158,7 @@
 ;;   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
@@ -244,6 +272,29 @@
   (not (port-mapping-empty? port-mapping)))
 
 
+\f
+;;; Request to run stuff
+;;; ====================
+
+(define-record-type <run-request>
+  (make-run-request proc when)
+  run-request?
+  (proc run-request-proc)
+  (when run-request-when))
+
+(define* (run proc #:optional when)
+  (make-run-request proc when))
+
+(define-syntax-rule (wrap body ...)
+  (lambda ()
+    body ...))
+
+(define-syntax-rule (run-wrap body ...)
+  (run (wrap body ...)))
+
+(define-syntax-rule (run-wrap-at body ... when)
+  (run (wrap body ...) when))
+
 \f
 ;;; Execution of agenda, and current agenda
 ;;; =======================================
@@ -260,7 +311,12 @@
              (agenda-run-once agenda))))
       (if (and stop-condition (stop-condition agenda))
           'done
-          (loop new-agenda)))))
+          (let ((updated-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 new-agenda (agenda-time) (gettimeofday))))
+            (loop updated-agenda))))))
 
 (define (agenda-run-once agenda)
   "Run once through the agenda, and produce a new agenda
@@ -279,21 +335,36 @@ based on the results"
       (let* ((proc (q-pop! queue))
              (proc-result (call-proc proc))
              (enqueue
-              (lambda (new-proc)
-                (enq! next-queue new-proc))))
+              (lambda (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 proc))))
+                    ((? integer? sec)
+                     (let ((time (cons sec 0)))
+                       (schedule-at! time (run-request-proc proc))))
+                    (((? integer? sec) . (? integer? usec))
+                     (schedule-at! request-time (run-request-proc proc)))
+                    (#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
           ;;   intent to run.  Use a (run foo) procedure
-          ((? procedure? new-proc)
+          ((? run-request? new-proc)
            (enqueue new-proc))
-          (((? procedure? new-procs) ...)
+          (((? run-request? new-procs) ...)
            (for-each
             (lambda (new-proc)
               (enqueue new-proc))
             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)))