X-Git-Url: https://jxself.org/git/?p=8sync.git;a=blobdiff_plain;f=8sync%2Factors.scm;h=045a43a1ddc97dc9d9fb4f27767b4ac8edecfbd9;hp=c694c489992abd9a99a9aca57f2afc605103e822;hb=a5c16530d2e253c0d56143c5337740b1f7a403ed;hpb=3d6f2e7cd2ec140db3a32c0f2a999b63b718a935 diff --git a/8sync/actors.scm b/8sync/actors.scm index c694c48..045a43a 100644 --- a/8sync/actors.scm +++ b/8sync/actors.scm @@ -25,7 +25,6 @@ #: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 @@ -48,6 +47,8 @@ actor-id-hive actor-id-string + actor-am-i-alive? + build-actions define-simple-actor @@ -70,11 +71,11 @@ 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 @@ -165,23 +166,53 @@ ;;; 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 @@ -190,38 +221,39 @@ (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))) @@ -251,6 +283,14 @@ (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 () ;; An address object (id #:init-keyword #:id @@ -264,15 +304,15 @@ ;; @@: 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 )) - (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. @@ -291,13 +331,13 @@ ;; (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) "@" @@ -318,19 +358,14 @@ (define %current-actor (make-parameter #f)) +(define (actor-am-i-alive? actor) + (hive-resolve-local-actor (actor-hive actor) (actor-id actor))) + ;;; 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 () (actions #:init-value (build-actions action ...) @@ -370,12 +405,25 @@ to come after class definition." (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 ) message) "Handle an ambassador failing to forward a message" 'TODO) +(define-method (hive-handle-cleanup-all (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 #:id (make-address @@ -383,6 +431,8 @@ to come after class definition." (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 )) @@ -439,6 +489,14 @@ to come after class definition." ;; unresumable continuation. (lambda () (hive-process-message hive new-message)))) +(define-record-type + (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 ) message) "Handle one message, or forward it via an ambassador" (define (maybe-autoreply actor) @@ -488,11 +546,12 @@ to come after class definition." (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))))) @@ -512,45 +571,37 @@ to come after class definition." 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 @@ -600,6 +651,7 @@ that method for documentation." 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)) @@ -663,22 +715,24 @@ Like create-actor, but permits supplying an 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