X-Git-Url: https://jxself.org/git/?p=8sync.git;a=blobdiff_plain;f=8sync%2Factors.scm;h=1b120ba77916e1e3f9bd08029cfa4398218a5e66;hp=c694c489992abd9a99a9aca57f2afc605103e822;hb=d23b593a5810b38d2517a44c09d49b2835c59e16;hpb=3d6f2e7cd2ec140db3a32c0f2a999b63b718a935 diff --git a/8sync/actors.scm b/8sync/actors.scm index c694c48..1b120ba 100644 --- a/8sync/actors.scm +++ b/8sync/actors.scm @@ -1,5 +1,5 @@ ;;; 8sync --- Asynchronous programming for Guile -;;; Copyright (C) 2016 Christopher Allan Webber +;;; Copyright © 2016, 2017 Christopher Allan Webber ;;; ;;; This file is part of 8sync. ;;; @@ -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 @@ -48,16 +47,18 @@ actor-id-hive actor-id-string + actor-alive? + build-actions - define-simple-actor + define-actor make-hive ;; There are more methods for the hive, but there's ;; no reason for the outside world to look at them maybe? hive-id - hive-create-actor hive-create-actor* + bootstrap-actor bootstrap-actor* create-actor create-actor* self-destruct @@ -70,11 +71,11 @@ message-auto-reply? - <- <-wait <-reply <-reply-wait + <- <-* <-wait <-wait* <-reply <-reply* <-reply-wait <-reply-wait* - call-with-message msg-receive msg-val + call-with-message mbody-receive mbody-val - ez-run-hive + run-hive bootstrap-message serialize-message write-message @@ -165,63 +166,126 @@ ;;; 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 - message-body-args))) - (8sync (hive-process-message hive message)))) +;; This is the internal, generalized message sending method. +;; Users shouldn't use it! Use the <-foo forms instead. -(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" +;; @@: 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)) - (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))) + (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 (<- to-id action . message-body-args) + "Send a message from an actor to another actor" + (send-message '() (%current-actor) to-id action + #f #f message-body-args)) + +(define (<-* send-options to-id action . message-body-args) + "Like <-*, but allows extra parameters via send-options" + (define* (really-send #:key (actor (%current-actor)) + #:allow-other-keys) + (send-message send-options actor to-id action + #f #f message-body-args)) + (apply really-send send-options)) + +(define (<-wait to-id action . message-body-args) + "Send a message from an actor to another, but wait until we get a response" + (wait-maybe-handle-errors + (send-message '() (%current-actor) to-id action + #f #t message-body-args))) + +(define (<-wait* send-options to-id action . message-body-args) + "Like <-wait, but allows extra parameters, for example whether to +#:accept-errors" + (define* (really-send #:key (actor (%current-actor)) + #:allow-other-keys) + (apply wait-maybe-handle-errors + (send-message send-options actor to-id action + #f #t message-body-args) + send-options)) + (apply really-send send-options)) ;; TODO: Intelligently ~propagate(ish) errors on -wait functions. ;; We might have `send-message-wait-brazen' to allow callers to ;; not have an exception thrown and instead just have a message with ;; the appropriate '*error* message returned. -(define (<-reply from-actor original-message . message-body-args) +(define (<-reply 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)))) - -(define (<-auto-reply from-actor original-message) + (when (message-needs-reply? original-message) + (send-message '() (%current-actor) (message-from original-message) '*reply* + original-message #f message-body-args))) + +(define (<-reply* send-options original-message . message-body-args) + "Like <-reply, but allows extra parameters via send-options" + (define* (really-send #:key (actor (%current-actor)) + #:allow-other-keys) + (send-message send-options actor + (message-from original-message) '*reply* + original-message #f message-body-args)) + (when (message-needs-reply? original-message) + (apply really-send send-options))) + +(define (<-auto-reply 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 '() actor (message-from original-message) '*auto-reply* + original-message #f '())) -(define (<-reply-wait from-actor original-message . message-body-args) +(define (<-reply-wait 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))) + (if (message-needs-reply? original-message) + (wait-maybe-handle-errors + (send-message '() (%current-actor) + (message-from original-message) '*reply* + original-message #t message-body-args)) + #f)) + +(define (<-reply-wait* send-options original-message + . message-body-args) + "Like <-reply-wait, but allows extra parameters via send-options" + (define* (really-send #:key (actor (%current-actor)) + #:allow-other-keys) + (apply wait-maybe-handle-errors + (send-message send-options actor + (message-from original-message) '*reply* + original-message #t message-body-args) + send-options)) + (when (message-needs-reply? original-message) + (apply really-send send-options))) + +(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 +315,14 @@ (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 @@ -264,40 +336,36 @@ ;; @@: 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) + + ;; valid values are: + ;; - #t as in, send the init message, but don't wait (default) + ;; - 'wait, as in wait on the init message + ;; - #f as in don't bother to init + (should-init #:init-value #t + #:allocation #:each-subclass) ;; This is the default, "simple" way to inherit and process messages. - (actions #:init-value '() + (actions #:init-value (build-actions + ;; Default init method is to do nothing. + (*init* (const #f)) + ;; 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. - -;; (define-record-type
-;; (make-address actor-id hive-id) ; @@: Do we want the trailing -id? -;; address? -;; (actor-id address-actor-id) -;; (hive-id address-hive-id)) -;; -;; (set-record-type-printer! -;;
-;; (lambda (record port) -;; (format port "" -;; (address-actor-id record) (address-hive-id record)))) -;; +;;; Addresses are vectors where the first part is the actor-id and +;;; the second part is the hive-id. This works well enough... they +;;; look decent being pretty-printed. (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) "@" @@ -318,23 +386,21 @@ (define %current-actor (make-parameter #f)) +(define (actor-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 () +(define-syntax-rule (define-actor class inherits + (action ...) + slots ...) + (define-class class inherits (actions #:init-value (build-actions action ...) - #:allocation #:each-subclass))) + #:allocation #:each-subclass) + slots ...)) ;;; The Hive @@ -370,12 +436,48 @@ 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) + ;; These are called at start and end of run-hive + (*init-all* hive-handle-init-all) + (*cleanup-all* hive-handle-cleanup-all)))) + +(define-method (hive-handle-init-all (hive ) message) + "Run *init* method on all actors in registry" + ;; We have to do this hack and run over the list + ;; twice, because hash-for-each would result in an unrewindable + ;; continuation, and to avoid the hash-map changing during the + ;; middle of this. + (define actor-ids + (hash-map->list (lambda (actor-id actor) actor-id) + (hive-actor-registry hive))) + (for-each (lambda (actor-id) + (let* ((actor (hash-ref (hive-actor-registry hive) + actor-id))) + (match (slot-ref actor 'should-init) + (#f #f) + ('wait + (<-wait actor-id '*init*)) + (_ + (<- actor-id '*init*))))) + actor-ids)) (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." + ;; We have to do this hack and run over the list + ;; twice, because hash-for-each would result in an unrewindable + ;; continuation, and to avoid the hash-map changing during the + ;; middle of this. + (define actor-ids + (hash-map->list (lambda (actor-id actor) actor-id) + (hive-actor-registry hive))) + (for-each (lambda (actor-id) + (<- actor-id '*cleanup*)) + actor-ids)) + (define* (make-hive #:key hive-id) (let ((hive (make #:id (make-address @@ -383,6 +485,8 @@ 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 )) @@ -390,7 +494,7 @@ to come after class definition." (define-method (hive-gen-actor-id (hive ) cookie) (make-address (if cookie - (string-append cookie "-" (big-random-number-string)) + (string-append cookie ":" (big-random-number-string)) (big-random-number-string)) (hive-id hive))) @@ -439,6 +543,14 @@ 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 +600,12 @@ 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 +625,37 @@ 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 @@ -580,49 +685,61 @@ to come after class definition." (hash-set! (hive-actor-registry hive) (actor-id actor) actor)) (define-method (%hive-create-actor (hive ) actor-class - init id-cookie) - "Actual method called by hive-create-actor. + init-args id-cookie send-init?) + "Actual method called by bootstrap-actor / create-actor. Since this is a define-method it can't accept fancy define* arguments, -so this gets called from the nicer hive-create-actor interface. See +so this gets called from the nicer bootstrap-actor interface. See that method for documentation." (let* ((actor-id (hive-gen-actor-id hive id-cookie)) (actor (apply make actor-class #:hive hive #:id actor-id - init))) + init-args)) + (actor-should-init (slot-ref actor 'should-init))) (hive-register-actor! hive actor) + ;; Maybe run actor init method + (when (and send-init? actor-should-init) + (let ((send-method + (if (eq? actor-should-init 'wait) + <-wait <-))) + (send-method actor-id '*init*))) ;; return the actor id actor-id)) -(define* (hive-create-actor hive actor-class #:rest init) +(define* (bootstrap-actor hive actor-class #:rest init-args) + "Create an actor on HIVE using ACTOR-CLASS passing in INIT-ARGS args" (%hive-create-actor hive actor-class - init #f)) + init-args (symbol->string (class-name actor-class)) + #f)) -(define* (hive-create-actor* hive actor-class id-cookie #:rest init) +(define* (bootstrap-actor* hive actor-class id-cookie #:rest init-args) + "Create an actor, but also allow customizing a 'cookie' added to the id +for debugging" (%hive-create-actor hive actor-class - init id-cookie)) + init-args id-cookie + #f)) (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) +;; (mbody-receive (<- bar baz) ;; (baz) ;; basil) -;; Emacs: (put 'msg-receive 'scheme-indent-function 2) +;; Emacs: (put 'mbody-receive 'scheme-indent-function 2) ;; @@: Or receive-msg or receieve-message or?? -(define-syntax-rule (msg-receive arglist message body ...) +(define-syntax-rule (mbody-receive arglist message body ...) "Call body with arglist (which can accept arguments like lambda*) applied from the message-body of message." (call-with-message message (lambda* arglist body ...))) -(define (msg-val message) +(define (mbody-val message) "Retrieve the first value from the message-body of message. Like single value return from a procedure call. Probably the most common case when waiting on a reply from some action invocation." @@ -635,26 +752,31 @@ common case when waiting on a reply from some action invocation." ;; TODO: move send-message and friends here...? -(define* (create-actor from-actor actor-class #:rest init) +(define* (create-actor from-actor actor-class #:rest init-args) "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*)." (%hive-create-actor (actor-hive from-actor) actor-class - init #f)) + init-args #f #t)) -(define* (create-actor* from-actor actor-class id-cookie #:rest init) +(define* (create-actor* from-actor actor-class id-cookie #:rest init-args) "Create an instance of actor-class. Return the new actor's id. Like create-actor, but permits supplying an id-cookie." (%hive-create-actor (actor-hive from-actor) actor-class - init id-cookie)) + init-args id-cookie #t)) + +(define* (self-destruct actor #:key (cleanup #t)) + "Remove an actor from the hive. -(define (self-destruct actor) - "Remove an actor from the hive." +Unless #:cleanup is set to #f, this will first have the actor handle +its '*cleanup* action handler." + (when cleanup + (<-wait (actor-id actor) '*cleanup*)) (hash-remove! (hive-actor-registry (actor-hive actor)) (actor-id actor))) @@ -663,26 +785,47 @@ Like create-actor, but permits supplying an id-cookie." ;;; 8sync bootstrap utilities ;;; ========================= -(define* (ez-run-hive hive initial-tasks #:key repl-server) +(define* (run-hive hive initial-tasks + #:key (cleanup #t) + (handle-signals (list SIGINT SIGTERM))) "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))) +Keyword arguments: + - #:cleanup: Whether to run *cleanup* on all actors. + - #:handle-sigactions: a list of signals to set up interrupt + handlers for, so cleanup sill still happen as expected. + Defaults to a list of SIGINT and SIGTERM." + (dynamic-wind + (const #f) + (lambda () + (define (run-it escape) + (define (handle-signal signum) + (restore-signals) + (escape signum)) + (for-each (lambda (signum) + (sigaction signum handle-signal)) + handle-signals) + (let* ((queue (list->q + (cons (bootstrap-message hive (actor-id hive) '*init-all*) + initial-tasks))) + (agenda (make-agenda #:pre-unwind-handler print-error-and-continue + #:queue queue))) + (run-agenda agenda))) + (call/ec run-it)) + ;; Run cleanup + (lambda () + (when cleanup + (run-hive-cleanup hive))))) + +(define (run-hive-cleanup hive) + (let ((queue (list->q (list (bootstrap-message hive (actor-id hive) + '*cleanup-all*))))) + (run-agenda + (make-agenda #:queue queue)))) (define (bootstrap-message hive to-id action . message-body-args) (wrap - (apply <- hive to-id action message-body-args))) + (apply <-* `(#:actor ,hive) to-id action message-body-args)))