big-random-number
big-random-number-string
simple-message-id-generator
- require-slot
<actor>
actor-id
- actor-hive
actor-message-handler
;;; Commenting out the <address> type for now;
actor-id-hive
actor-id-string
- make-action-dispatch
+ simple-dispatcher build-actions make-action-dispatch
define-simple-actor
<hive>
message-to message-action message-from
message-id message-body message-in-reply-to
message-wants-reply
- message-ref
- send-message send-message-wait
- reply-message reply-message-wait
+ message-auto-reply?
+
+ <- <-wait <-reply <-reply-wait
+
+ call-with-message msg-receive =>
ez-run-hive
- hive-bootstrap-message
+ bootstrap-message
serialize-message write-message
serialize-message-pretty pprint-message
(set! counter (1+ counter))
(string-append prefix (number->string counter)))))
-(define (require-slot slot-name)
- "Generate something for #:init-thunk to complain about unfilled slot"
- (lambda ()
- (throw 'required-slot
- (format #f "Slot ~s not filled" slot-name)
- slot-name)))
-
\f
;;; Messages
(define-record-type <message>
(make-message-intern id to from action
- body in-reply-to wants-reply ; do we need hive-proxy?
- ;; Are these still needed?
- replied deferred-reply)
+ body in-reply-to wants-reply
+ replied)
message?
(id message-id)
(to message-to)
(body message-body)
(in-reply-to message-in-reply-to)
(wants-reply message-wants-reply)
-
- ;; See XUDD source for these. Not use yet, maybe eventually will be?
- ;; XUDD uses them for autoreply.
- ;; Requiring mutation on message objects is clearly not great,
- ;; but it may be worth it...? Investigate!
- (replied message-replied set-message-replied!)
- (deferred-reply message-deferred-reply set-message-deferred-reply!))
+ (replied message-replied set-message-replied!))
(define* (make-message id to from action body
#:key in-reply-to wants-reply
- replied deferred-reply)
+ replied)
(make-message-intern id to from action body
- in-reply-to wants-reply replied
- deferred-reply))
-
-;; Note: the body of messages is currently an alist, but it's created
-;; from a keyword based property list (see the following two functions).
-;; But, that's an extra conversion step, and maybe totally unnecessary:
-;; we already have message-ref, and this could just pull a keyword
-;; from a property list.
-;; The main ways this might be useful are error checking,
-;; serialization across the wire (but even that might require some
-;; change), and using existing tooling (though adding new tooling
-;; would be negligible in implementation effort.)
-
-;; This cons cell is immutable and unique (for eq? tests)
-(define %nothing-provided (cons 'nothing 'provided))
-
-(define* (message-ref message key #:optional (dflt %nothing-provided))
- "Extract KEY from body of MESSAGE.
-
-Optionally set default with [DFLT]
-If key not found and DFLT not provided, throw an error."
- (let ((result (assoc key (message-body message))))
- (if result (cdr result)
- (if (eq? dflt %nothing-provided)
- (throw 'message-missing-key
- "Message body does not contain key and no default provided"
- #:key key
- #:message message)
- dflt))))
-
-
-(define (message-needs-reply message)
+ in-reply-to wants-reply replied))
+
+(define (message-auto-reply? message)
+ (eq? (message-action message) '*auto-reply*))
+
+(define (message-needs-reply? message)
"See if this message needs a reply still"
(and (message-wants-reply message)
- (not (or (message-replied message)
- (message-deferred-reply message)))))
+ (not (message-replied message))))
(define (kwarg-list-to-alist args)
args)))))
-(define (send-message from-actor to-id action . message-body-args)
+;;; 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 )
+
+(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
- (kwarg-list-to-alist message-body-args))))
- (8sync-nowait (hive-process-message hive message))))
+ message-body-args)))
+ (8sync (hive-process-message hive message))))
-(define (send-message-wait from-actor to-id action . message-body-args)
+(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
- (kwarg-list-to-alist message-body-args)
+ message-body-args
#:wants-reply #t)))
(abort-to-prompt abort-to from-actor message)))
;; not have an exception thrown and instead just have a message with
;; the appropriate '*error* message returned.
-(define (reply-message from-actor original-message
- . message-body-args)
+(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*
- (kwarg-list-to-alist message-body-args)
+ message-body-args
#:in-reply-to (message-id original-message))))
- (8sync-nowait (hive-process-message hive new-message))))
+ (8sync (hive-process-message hive new-message))))
-(define (reply-message-wait from-actor original-message
- . 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))))
+
+(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))
(new-message (make-message (hive-gen-message-id hive)
(message-from original-message)
(actor-id from-actor) '*reply*
- (kwarg-list-to-alist message-body-args)
+ message-body-args
#:wants-reply #t
#:in-reply-to (message-id original-message))))
(abort-to-prompt abort-to from-actor new-message)))
(define-class <actor> ()
;; An address object
- (id #:init-thunk (require-slot "id")
- #:init-keyword #:id
+ (id #:init-keyword #:id
#:getter actor-id)
;; The hive we're connected to.
;; We need this to be able to send messages.
- (hive #:init-thunk (require-slot "hive")
- #:init-keyword #:hive
+ (hive #:init-keyword #:hive
#:accessor actor-hive)
;; How we receive and process new messages
- (message-handler #:init-thunk (require-slot "message-handler")
- #:allocation #:each-subclass))
+ (message-handler #:allocation #:each-subclass))
(define-method (actor-message-handler (actor <actor>))
(slot-ref actor 'message-handler))
(let* ((action (message-action message))
(method (assoc-ref action-map action)))
(if (not method)
+ ;; @@: There's every possibility this should be handled in
+ ;; hive-process-message instead.
(throw 'action-not-found
"No appropriate action handler found for actor"
#:action action
#:actor actor
#:message message
#:available-actions (map car action-map)))
- (method actor message))))
+ (apply method actor message (message-body message)))))
(define-syntax %expand-action-item
(syntax-rules ()
- ((_ ((action-name action-args ...) body ...))
- (cons (quote action-name)
- (lambda (action-args ...)
- body ...)))
((_ (action-name handler))
(cons (quote action-name) handler))))
+(define-syntax-rule (build-actions action-item ...)
+ "Build a mapping of actions. Same syntax as make-action-dispatch
+but this doesn't build the dispatcher for you (you probably want to
+pass it to simple-dispatcher).
+
+The advantage here is that since this simply builds an alist, you can
+compose it with other action maps."
+ (list (%expand-action-item action-item) ...))
+
(define-syntax make-action-dispatch
(syntax-rules ()
"Expand a list of action names and actions into an alist
((party actor message)
(display \"Life of the party!\")))"
((make-action-dispatch action-item ...)
- (simple-dispatcher
- (list (%expand-action-item action-item) ...)))))
+ (simple-dispatcher (build-actions action-item ...)))))
(define-syntax-rule (define-simple-actor class actions ...)
(define-class class (<actor>)
(define-generic hive-handle-failed-forward)
(define-class <hive> (<actor>)
- ;; This gets set to itself immediately after being created
- (hive #:init-value #f)
(actor-registry #:init-thunk make-hash-table
#:getter hive-actor-registry)
(msg-id-generator #:init-thunk simple-message-id-generator
'*forward*
`((original . ,message))))
+(define-method (hive-reply-with-error (hive <hive>) original-message
+ error-key error-args)
+ ;; We only supply the error-args if the original sender is on the same hive
+ (define (orig-actor-on-same-hive?)
+ (equal? (hive-id hive)
+ (address-hive-id (message-from original-message))))
+ (set-message-replied! original-message #t)
+ (let* ((new-message-body
+ (if (orig-actor-on-same-hive?)
+ `(#:original-message ,original-message
+ #:error-key ,error-key
+ #:error-args ,error-args)
+ `(#:original-message ,original-message
+ #:error-key ,error-key)))
+ (new-message (make-message (hive-gen-message-id hive)
+ (message-from original-message)
+ (actor-id hive) '*error*
+ new-message-body
+ #:in-reply-to (message-id original-message))))
+ (8sync (hive-process-message hive new-message))))
+
(define-method (hive-process-message (hive <hive>) message)
"Handle one message, or forward it via an ambassador"
(define (maybe-autoreply actor)
;; Possibly autoreply
- (if (message-needs-reply message)
- ;; @@: Should we give *autoreply* as the action instead of *reply*?
- (reply-message actor message
- #:*auto-reply* #t)))
+ (if (message-needs-reply? message)
+ (<-auto-reply actor message)))
(define (resolve-actor-to)
"Get the actor the message was aimed at"
actor))
(define (call-catching-coroutine thunk)
+ (define (call-catching-errors)
+ ;; TODO: maybe parameterize (or attach to hive) and use
+ ;; maybe-catch-all from agenda.scm
+ ;; @@: Why not just use with-throw-handler and let the catch
+ ;; happen at the agenda? That's what we used to do, but
+ ;; it ended up with a SIGABRT. See:
+ ;; http://lists.gnu.org/archive/html/bug-guile/2016-05/msg00003.html
+ (catch #t
+ thunk
+ ;; In the actor model, we don't totally crash on errors.
+ (lambda _ #f)
+ ;; If an error happens, we raise it
+ (lambda (key . args)
+ (if (message-needs-reply? message)
+ ;; If the message is waiting on a reply, let them know
+ ;; something went wrong.
+ (hive-reply-with-error hive message key args))
+ ;; print error message
+ (apply print-error-and-continue key args))))
(call-with-prompt (hive-prompt hive)
- thunk
+ call-catching-errors
(lambda (kont actor message)
- (let ((hive (actor-hive actor)))
- ;; Register the coroutine
- (hash-set! (hive-waiting-coroutines hive)
- (message-id message)
- (cons (actor-id actor) kont))
- ;; Send off the message
- (8sync (hive-process-message hive message))))))
+ ;; Register the coroutine
+ (hash-set! (hive-waiting-coroutines hive)
+ (message-id message)
+ (cons (actor-id actor) kont))
+ ;; Send off the message
+ (8sync (hive-process-message hive message)))))
(define (process-local-message)
(let ((actor (resolve-actor-to)))
result)))))
(define (resume-waiting-coroutine)
- (call-catching-coroutine
- (lambda ()
- (match (hash-remove! (hive-waiting-coroutines hive)
- (message-in-reply-to message))
- ((_ . (resume-actor-id . kont))
- (if (not (equal? (message-to message)
- resume-actor-id))
- (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
- #:message message))
- (let (;; @@: How should we resolve resuming coroutines to actors who are
- ;; now gone?
- (actor (resolve-actor-to))
- (result (kont message)))
- (maybe-autoreply actor)
- result))
- (#f (throw 'no-waiting-coroutine
- "message in-reply-to tries to resume nonexistent coroutine"
- message))))))
+ (cond
+ ((or (eq? (message-action message) '*reply*)
+ (eq? (message-action message) '*auto-reply*))
+ (call-catching-coroutine
+ (lambda ()
+ (match (hash-remove! (hive-waiting-coroutines hive)
+ (message-in-reply-to message))
+ ((_ . (resume-actor-id . kont))
+ (if (not (equal? (message-to message)
+ resume-actor-id))
+ (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
+ #:message message))
+ (let (;; @@: How should we resolve resuming coroutines to actors who are
+ ;; now gone?
+ (actor (resolve-actor-to))
+ (result (kont message)))
+ (maybe-autoreply actor)
+ result))
+ (#f (throw 'no-waiting-coroutine
+ "message in-reply-to tries to resume nonexistent coroutine"
+ message))))))
+ ;; Yikes, we must have gotten an error or something back
+ (else
+ ;; @@: 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)))))
(define (process-remote-message)
;; Find the ambassador
(process-remote-message))))
(define-method (hive-actor-local? (hive <hive>) address)
- (hash-ref (hive-actor-registry hive) address))
+ (equal? (hive-id hive) (address-hive-id address)))
(define-method (hive-register-actor! (hive <hive>) (actor <actor>))
(hash-set! (hive-actor-registry hive) (actor-id actor) actor))
that method for documentation."
(let* ((actor-id (hive-gen-actor-id hive id-cookie))
(actor (apply make actor-class
- ;; @@: If we switch to a hive-proxy, do it here
#:hive hive
#:id actor-id
init)))
(%hive-create-actor hive actor-class
init id-cookie))
+(define (call-with-message message proc)
+ "Applies message body arguments into procedure, with message as first
+argument. Similar to call-with-values in concept."
+ (apply proc message (message-body message)))
+
+;; (msg-receive (<- bar baz)
+;; (baz)
+;; basil)
-;; TODO: Give actors this instead of the actual hive reference
-(define-class <hive-proxy> ()
- (send-message #:getter proxy-send-message
- #:init-keyword #:send-message)
- (create-actor #:getter proxy-create-actor
- #:init-keyword #:create-actor))
+;; Emacs: (put 'msg-receive 'scheme-indent-function 2)
-;; Live the hive proxy, but has access to the hive itself...
-(define-class <debug-hive-proxy> (<hive-proxy>)
- (hive #:init-keyword #:hive))
+;; @@: Or receive-msg or receieve-message or??
+(define-syntax-rule (msg-receive arglist the-message body ...)
+ (call-with-message the-message
+ (lambda* arglist
+ body ...)))
+
+;; Emacs: (put '=> 'scheme-indent-function 2)
+;;; An experimental alias.
+(define-syntax-rule (=> rest ...)
+ (msg-receive rest ...))
\f
;; TODO: move send-message and friends here...?
-;; TODO: Rewrite this inside of a <hive-proxy> ?
(define* (create-actor from-actor actor-class #:rest init)
"Create an instance of actor-class. Return the new actor's id.
This is the method actors should call directly (unless they want
to supply an id-cookie, in which case they should use
create-actor*)."
- (8sync (%hive-create-actor (actor-hive from-actor) actor-class
- init #f)))
+ (%hive-create-actor (actor-hive from-actor) actor-class
+ init #f))
(define* (create-actor* from-actor actor-class id-cookie #:rest init)
"Create an instance of actor-class. Return the new actor's id.
Like create-actor, but permits supplying an id-cookie."
- (8sync (%hive-create-actor (actor-hive from-actor) actor-class
- init id-cookie)))
+ (%hive-create-actor (actor-hive from-actor) actor-class
+ init id-cookie))
(define (self-destruct actor)
(spawn-and-queue-repl-server! agenda)))
(start-agenda agenda)))
-(define (hive-bootstrap-message hive to-id action . message-body-args)
+(define (bootstrap-message hive to-id action . message-body-args)
(wrap
- (apply send-message hive to-id action message-body-args)))
+ (apply <- hive to-id action message-body-args)))
\f
(message-body message)
(message-in-reply-to message)
(message-wants-reply message)
- (message-replied message)
- (message-deferred-reply message)))
+ (message-replied message)))
(define* (write-message message #:optional (port (current-output-port)))
"Write out a message to a port for easy reading later.
(body ,(message-body message))
(in-reply-to ,(message-in-reply-to message))
(wants-reply ,(message-wants-reply message))
- (replied ,(message-replied message))
- (deferred-reply ,(message-deferred-reply message))))
+ (replied ,(message-replied message))))
(define (pprint-message message)
"Pretty print a message."
(define* (read-message #:optional (port (current-input-port)))
"Read a message serialized via serialize-message from PORT"
(match (read port)
- ((id to from action body in-reply-to wants-reply replied deferred-reply)
+ ((id to from action body in-reply-to wants-reply replied)
(make-message-intern
id to from action body
- in-reply-to wants-reply replied deferred-reply))
+ in-reply-to wants-reply replied))
(anything-else
(throw 'message-read-bad-structure
"Could not read message from structure"
projects / 8sync.git / blobdiff