#:export (<agenda>
make-agenda agenda?
agenda-queue agenda-prompt-tag
- agenda-read-port-map agenda-write-port-map agenda-except-port-map
+ agenda-read-port-map agenda-write-port-map
agenda-schedule
make-async-prompt-tag
run-it wrap wrap-apply run run-at run-delay
- 8sync 8sync-delay
+ 8sync-delay
8sync-run 8sync-run-at 8sync-run-delay
- 8sync-nowait
+ 8sync
8sleep
- catch-8sync
-
;; used for introspecting the error, but a method for making
;; is not exposed
wrapped-exception?
"Invalid request passed back via an (8sync) procedure."
async-request))))
-(define-record-type <wrapped-exception>
- (make-wrapped-exception key args stacks)
- wrapped-exception?
- (key wrapped-exception-key)
- (args wrapped-exception-args)
- (stacks wrapped-exception-stacks))
-
-(define-syntax-rule (propagate-%async-exceptions body)
- (let ((body-result body))
- (if (wrapped-exception? body-result)
- (throw '8sync-caught-error
- (wrapped-exception-key body-result)
- (wrapped-exception-args body-result)
- (wrapped-exception-stacks body-result))
- body-result)))
-
-(define-syntax 8sync
- (syntax-rules ()
- "Run BODY asynchronously (8synchronously?) at a prompt, then return.
-
-Possibly specify WHEN as the second argument."
- ((8sync body)
- (8sync-run body))
- ((8sync body when)
- (8sync-run-at body when))))
-
-(define-syntax-rule (8sync-run body ...)
- (8sync-run-at body ... #f))
-
-(define-syntax-rule (8sync-run-at body ... when)
- (propagate-%async-exceptions
- (8sync-abort-to-prompt
- ;; Send an asynchronous request to apply a continuation to the
- ;; following function, then handle that as a request to the agenda
- (make-async-request
- (lambda (kont)
- ;; We're making a run request
- (make-run-request
- ;; Wrapping the following execution to run...
- (wrap
- ;; Once we get the result from the inner part, we'll resume
- ;; this continuation, but first
- ;; @@: Is this running immediately, or queueing the result
- ;; after evaluation for the next agenda tick? It looks
- ;; like evaluating immediately. Is that what we want?
- (kont
- ;; Any unhandled errors are caught
- (let ((exception-stack #f))
- (catch #t
- ;; Run the actual code the user requested
- (lambda ()
- body ...)
- ;; If something bad happened and we didn't catch it,
- ;; we'll wrap it up in such a way that the continuation
- ;; can address it
- (lambda (key . args)
- (cond
- ((eq? key '8sync-caught-error)
- (match args
- ((orig-key orig-args orig-stacks)
- (make-wrapped-exception
- orig-key orig-args
- (cons exception-stack orig-stacks)))))
- (else
- (make-wrapped-exception key args
- (list exception-stack)))))
- (lambda _
- (set! exception-stack (make-stack #t 1 0)))))))
- when))))))
-
-(define-syntax-rule (8sync-run-delay body ... delay-time)
- (8sync-run-at body ... (tdelta delay-time)))
-
-(define-syntax-rule (8sync-delay args ...)
- (8sync-run-delay args ...))
-
-;; TODO: Write (%run-immediately)
-
-(define-syntax-rule (8sync-nowait body)
+(define-syntax-rule (8sync body ...)
"Run body asynchronously but ignore its result...
forge ahead in our current function!"
(8sync-abort-to-prompt
;; Otherwise we sometimes get errors like
;; "Zero values returned to single-valued continuation""
(wrap (kont #f)) #f)
- (make-run-request (lambda () body) #f))))))
-
-(define-syntax-rule (catch-8sync exp (handler-key handler) ...)
- (catch '8sync-caught-error
- (lambda ()
- exp)
- (lambda (_ orig-key orig-args orig-stacks)
- (cond
- ((or (eq? handler-key #t)
- (eq? orig-key handler-key))
- (apply handler orig-stacks orig-args)) ...
- (else (raise '8sync-caught-error
- orig-key orig-args orig-stacks))))))
-
-;; This is sugar... and could probably be considerably
-;; simplified and optimized. But whatever.
-(define-syntax-rule (8sleep time)
- (8sync-delay 'no-op time))
+ (make-run-request (lambda () body ...) #f))))))
+
+;; TODO: Rewrite when we move to this being just `sleep'.
+(define (8sleep time)
+ (8sync-abort-to-prompt
+ (make-async-request
+ (lambda (kont)
+ (make-run-request (lambda () (kont #f)) (tdelta time))))))
+;; Voluntarily yield execution
+(define (yield) ; @@: should this be define-inlinable?
+ "Voluntarily yield execution to the scheduler."
+ (8sync-abort-to-prompt
+ (make-async-request
+ (lambda (kont)
+ (make-run-request (lambda () (kont #f)) #f)))))
\f
;;; Execution of agenda, and current agenda
(selector agenda))
0)))
(or (has-items? agenda-read-port-map)
- (has-items? agenda-write-port-map)
- (has-items? agenda-except-port-map)))
+ (has-items? agenda-write-port-map)))
(if (or (ports-to-select?)
;; select doubles as sleep...
((? write-request? write-request)
(agenda-handle-write-request! agenda write-request))
;; do nothing
- ;; @@: Why not throw an error?
+ ;; Remember, we don't throw an error here because procedures can
+ ;; return a run request, eg with run-it, at the end of their
+ ;; evaluation to keep looping.
+ ;; @@: Though is this really a useful feature?
(_ #f)))
;; @@: We might support delay-wrapped procedures here
(match proc-result
projects / 8sync.git / blobdiff