#:use-module (ice-9 match)
#:use-module (ice-9 pretty-print)
#:use-module (8sync agenda)
- #:use-module (8sync repl)
#:export (;; utilities... ought to go in their own module
big-random-number
big-random-number-string
actor-id-hive
actor-id-string
+ actor-am-i-alive?
+
build-actions
define-simple-actor
message-auto-reply?
- <- <-wait <-reply <-reply-wait
+ <- <-wait <-wait* <-reply <-reply-wait <-reply-wait*
call-with-message msg-receive msg-val
- ez-run-hive
+ run-hive
bootstrap-message
serialize-message write-message
;;; 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
(call/ec find-message-handler))
(apply method actor message (message-body message)))
+(define-syntax-rule (build-actions (symbol method) ...)
+ "Construct an alist of (symbol . method), where the method is wrapped
+with wrap-apply to facilitate live hacking and allow the method definition
+to come after class definition."
+ (list
+ (cons (quote symbol)
+ (wrap-apply method)) ...))
+
(define-class <actor> ()
;; An address object
(id #:init-keyword #:id
;; @@: There's no reason not to use #:class instead of
;; #:each-subclass anywhere in this file, except for
;; Guile bug #25211 (#:class is broken in Guile 2.2)
- #:allocation #:each-subclass)
+ #:allocation #:each-subclass
+ #:getter actor-message-handler)
;; This is the default, "simple" way to inherit and process messages.
- (actions #:init-value '()
+ (actions #:init-value (build-actions
+ ;; Default cleanup method is to do nothing.
+ (*cleanup* (const #f)))
#:allocation #:each-subclass))
-(define-method (actor-message-handler (actor <actor>))
- (slot-ref actor 'message-handler))
-
;;; So these are the nicer representations of addresses.
;;; However, they don't serialize so easily with scheme read/write, so we're
;;; using the simpler cons cell version below for now.
;;
(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) "@"
(define %current-actor
(make-parameter #f))
+(define (actor-am-i-alive? actor)
+ (hive-resolve-local-actor (actor-hive actor) (actor-id actor)))
+
\f
;;; Actor utilities
;;; ===============
-(define-syntax-rule (build-actions (symbol method) ...)
- "Construct an alist of (symbol . method), where the method is wrapped
-with wrap-apply to facilitate live hacking and allow the method definition
-to come after class definition."
- (list
- (cons (quote symbol)
- (wrap-apply method)) ...))
-
(define-syntax-rule (define-simple-actor class action ...)
(define-class class (<actor>)
(actions #:init-value (build-actions action ...)
(build-actions
;; This is in the case of an ambassador failing to forward a
;; message... it reports it back to the hive
- (*failed-forward* hive-handle-failed-forward))))
+ (*failed-forward* hive-handle-failed-forward)
+ (*cleanup-all* hive-handle-cleanup-all))))
(define-method (hive-handle-failed-forward (hive <hive>) message)
"Handle an ambassador failing to forward a message"
'TODO)
+(define-method (hive-handle-cleanup-all (hive <hive>) message)
+ "Send a message to all actors in our registry to clean themselves up."
+ ;; Unfortunately we have to do this hack and run over the list
+ ;; twice, because hash-for-each would result in an unrewindable
+ ;; continuation.
+ (define actor-ids
+ (hash-map->list (lambda (actor-id actor) actor-id)
+ (hive-actor-registry hive)))
+ (for-each (lambda (actor-id)
+ (<- hive actor-id '*cleanup*))
+ actor-ids))
+
(define* (make-hive #:key hive-id)
(let ((hive (make <hive>
#:id (make-address
(big-random-number-string))))))
;; Set the hive's actor reference to itself
(set! (actor-hive hive) hive)
+ ;; Register the actor with itself
+ (hive-register-actor! hive hive)
hive))
(define-method (hive-id (hive <hive>))
;; 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)))))
result))))))
(define (resume-waiting-coroutine)
- (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)))))
+ (case (message-action message)
+ ;; standard reply / auto-reply
+ ((*reply* *auto-reply* *error*)
+ (call-catching-coroutine
+ (lambda ()
+ (match (hash-remove! (hive-waiting-coroutines hive)
+ (message-in-reply-to message))
+ ((_ . waiting)
+ (if (not (equal? (message-to message)
+ (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 (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))
+ (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))))))
+ ;; Unhandled action for a reply!
+ (else
+ (throw 'hive-unresumable-coroutine
+ "Won't resume coroutine, nonsense action on reply message"
+ #:action (message-action message)
+ #:message message))))
(define (process-remote-message)
;; Find the ambassador
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))
;;; 8sync bootstrap utilities
;;; =========================
-(define* (ez-run-hive hive initial-tasks #:key repl-server)
- "Start up an agenda and run HIVE in it with INITIAL-TASKS.
-
-Should we start up a cooperative REPL for live hacking? REPL-SERVER
-wants to know! You can pass it #t or #f, or if you want to specify a port,
-an integer."
- (let* ((queue (list->q initial-tasks))
- (agenda (make-agenda #:pre-unwind-handler print-error-and-continue
- #:queue queue)))
- (cond
- ;; If repl-server is an integer, we'll use that as the port
- ((integer? repl-server)
- (spawn-and-queue-repl-server! agenda repl-server))
- (repl-server
- (spawn-and-queue-repl-server! agenda)))
- (start-agenda agenda)))
+(define* (run-hive hive initial-tasks)
+ "Start up an agenda and run HIVE in it with INITIAL-TASKS."
+ (dynamic-wind
+ (const #f)
+ (lambda ()
+ (let* ((queue (list->q initial-tasks))
+ (agenda (make-agenda #:pre-unwind-handler print-error-and-continue
+ #:queue queue)))
+ (start-agenda agenda)))
+ ;; Run cleanup
+ (lambda ()
+ (run-hive-cleanup hive))))
+
+(define (run-hive-cleanup hive)
+ (let ((queue (list->q (list (bootstrap-message hive (actor-id hive)
+ '*cleanup-all*)))))
+ (start-agenda
+ (make-agenda #:queue queue))))
(define (bootstrap-message hive to-id action . message-body-args)
(wrap
projects / 8sync.git / blobdiff