message-auto-reply?
- <- <-wait <-reply <-reply-wait
+ <- <-wait <-wait* <-reply <-reply-wait <-reply-wait*
call-with-message msg-receive msg-val
;;; See: https://web.archive.org/web/20081223021934/http://mumble.net/~jar/articles/oo-moon-weinreb.html
;;; (also worth seeing: http://mumble.net/~jar/articles/oo.html )
+;; This is the internal, generalized message sending method.
+;; Users shouldn't use it! Use the <-foo forms instead.
+
+;; @@: Could we get rid of some of the conditional checks through
+;; some macro-foo?
+
+(define-inlinable (send-message send-options from-actor to-id action
+ replying-to-message wants-reply?
+ message-body-args)
+ (if replying-to-message
+ (set-message-replied! replying-to-message #t))
+ (let* ((hive (actor-hive from-actor))
+ (new-message
+ (make-message (hive-gen-message-id hive) to-id
+ (actor-id from-actor) action
+ message-body-args
+ #:wants-reply wants-reply?
+ #:in-reply-to
+ (if replying-to-message
+ (message-id replying-to-message)
+ #f))))
+ (if wants-reply?
+ (abort-to-prompt (hive-prompt (actor-hive from-actor))
+ from-actor new-message send-options)
+ ;; @@: It might be that eventually we pass in send-options
+ ;; here too. Since <-wait and <-reply-wait are the only ones
+ ;; that use it yet, for now it kind of just makes things
+ ;; confusing.
+ (8sync (hive-process-message hive new-message)))))
+
+
(define (<- from-actor to-id action . message-body-args)
"Send a message from an actor to another actor"
- (let* ((hive (actor-hive from-actor))
- (message (make-message (hive-gen-message-id hive) to-id
- (actor-id from-actor) action
- message-body-args)))
- (8sync (hive-process-message hive message))))
+ (send-message '() from-actor to-id action
+ #f #f message-body-args))
+
+(define (<-wait* send-options from-actor to-id action . message-body-args)
+ "Like <-wait, but allows extra parameters, for example whether to
+#:accept-errors"
+ (apply wait-maybe-handle-errors
+ (send-message send-options from-actor to-id action
+ #f #t message-body-args)
+ send-options))
(define (<-wait from-actor to-id action . message-body-args)
"Send a message from an actor to another, but wait until we get a response"
- (let* ((hive (actor-hive from-actor))
- (abort-to (hive-prompt (actor-hive from-actor)))
- (message (make-message (hive-gen-message-id hive) to-id
- (actor-id from-actor) action
- message-body-args
- #:wants-reply #t)))
- (abort-to-prompt abort-to from-actor message)))
+ (apply <-wait* '() from-actor to-id action message-body-args))
;; TODO: Intelligently ~propagate(ish) errors on -wait functions.
;; We might have `send-message-wait-brazen' to allow callers to
(define (<-reply from-actor original-message . message-body-args)
"Reply to a message"
- (set-message-replied! original-message #t)
- (let* ((hive (actor-hive from-actor))
- (new-message (make-message (hive-gen-message-id hive)
- (message-from original-message)
- (actor-id from-actor) '*reply*
- message-body-args
- #:in-reply-to (message-id original-message))))
- (8sync (hive-process-message hive new-message))))
+ (send-message '() from-actor (message-from original-message) '*reply*
+ original-message #f message-body-args))
(define (<-auto-reply from-actor original-message)
"Auto-reply to a message. Internal use only!"
- (set-message-replied! original-message #t)
- (let* ((hive (actor-hive from-actor))
- (new-message (make-message (hive-gen-message-id hive)
- (message-from original-message)
- (actor-id from-actor) '*auto-reply*
- '()
- #:in-reply-to (message-id original-message))))
- (8sync (hive-process-message hive new-message))))
+ (send-message '() from-actor (message-from original-message) '*auto-reply*
+ original-message #f '()))
+
+(define (<-reply-wait* send-options from-actor original-message
+ . message-body-args)
+ "Reply to a messsage, but wait until we get a response"
+ (apply wait-maybe-handle-errors
+ (send-message send-options from-actor
+ (message-from original-message) '*reply*
+ original-message #t message-body-args)
+ send-options))
(define (<-reply-wait from-actor original-message . message-body-args)
"Reply to a messsage, but wait until we get a response"
- (set-message-replied! original-message #t)
- (let* ((hive (actor-hive from-actor))
- (abort-to (hive-prompt (actor-hive from-actor)))
- (new-message (make-message (hive-gen-message-id hive)
- (message-from original-message)
- (actor-id from-actor) '*reply*
- message-body-args
- #:wants-reply #t
- #:in-reply-to (message-id original-message))))
- (abort-to-prompt abort-to from-actor new-message)))
+ (apply <-reply-wait* '() from-actor original-message message-body-args))
+
+(define* (wait-maybe-handle-errors message
+ #:key accept-errors
+ #:allow-other-keys)
+ "Before returning a message to a waiting caller, see if we need to
+raise an exception if an error."
+ (define action (message-action message))
+ (cond ((and (eq? action '*error*)
+ (not accept-errors))
+ (throw 'hive-unresumable-coroutine
+ "Won't resume coroutine; got an *error* as a reply"
+ #:message message))
+ (else message)))
\f
;;
(define (make-address actor-id hive-id)
- (cons actor-id hive-id))
+ (vector actor-id hive-id))
(define (address-actor-id address)
- (car address))
+ (vector-ref address 0))
(define (address-hive-id address)
- (cdr address))
+ (vector-ref address 1))
(define (address->string address)
(string-append (address-actor-id address) "@"
;; unresumable continuation.
(lambda () (hive-process-message hive new-message))))
+(define-record-type <waiting-on-reply>
+ (make-waiting-on-reply actor-id kont send-options)
+ waiting-on-reply?
+ (actor-id waiting-on-reply-actor-id)
+ (kont waiting-on-reply-kont)
+ (send-options waiting-on-reply-send-options))
+
+
(define-method (hive-process-message (hive <hive>) message)
"Handle one message, or forward it via an ambassador"
(define (maybe-autoreply actor)
(8sync (queued-error-handling-thunk))))
(call-with-prompt (hive-prompt hive)
call-catching-errors
- (lambda (kont actor message)
+ (lambda (kont actor message send-options)
;; Register the coroutine
(hash-set! (hive-waiting-coroutines hive)
(message-id message)
- (cons (actor-id actor) kont))
+ (make-waiting-on-reply
+ (actor-id actor) kont send-options))
;; Send off the message
(8sync (hive-process-message hive message)))))
(define (resume-waiting-coroutine)
(case (message-action message)
;; standard reply / auto-reply
- ((*reply* *auto-reply*)
+ ((*reply* *auto-reply* *error*)
(call-catching-coroutine
(lambda ()
(match (hash-remove! (hive-waiting-coroutines hive)
(message-in-reply-to message))
- ((_ . (resume-actor-id . kont))
+ ((_ . waiting)
(if (not (equal? (message-to message)
- resume-actor-id))
+ (waiting-on-reply-actor-id waiting)))
(throw 'resuming-to-wrong-actor
"Attempted to resume a coroutine to the wrong actor!"
#:expected-actor-id (message-to message)
- #:got-actor-id resume-actor-id
+ #:got-actor-id (waiting-on-reply-actor-id waiting)
#:message message))
- (let (;; @@: How should we resolve resuming coroutines to actors who are
- ;; now gone?
- (actor (resolve-actor-to))
- (result (kont message)))
+ (let* (;; @@: How should we resolve resuming coroutines to actors who are
+ ;; now gone?
+ (actor (resolve-actor-to))
+ (kont (waiting-on-reply-kont waiting))
+ (result (kont message)))
(maybe-autoreply actor)
result))
(#f (throw 'no-waiting-coroutine
"message in-reply-to tries to resume nonexistent coroutine"
message))))))
- ;; Yikes, an error!
- ((*error*)
- ;; @@: Not what we want in the long run?
- ;; What we'd *prefer* to do is to resume this message
- ;; and throw an error inside the message handler
- ;; (say, from send-mesage-wait), but that causes a SIGABRT (??!!)
- (hash-remove! (hive-waiting-coroutines hive)
- (message-in-reply-to message))
- (let ((explaination
- (if (eq? (message-action message) '*reply*)
- "Won't resume coroutine; got an *error* as a reply"
- "Won't resume coroutine because action is not *reply*")))
- (throw 'hive-unresumable-coroutine
- explaination #:message message)))
;; Unhandled action for a reply!
(else
(throw 'hive-unresumable-coroutine
init #f))
(define* (hive-create-actor* hive actor-class id-cookie #:rest init)
+ "Create an actor, but also add a 'cookie' to the name for debugging"
(%hive-create-actor hive actor-class
init id-cookie))