X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=8sync%2Factors.scm;h=ceb2980f533e93eab250c85e908dd05e6f885edf;hb=fa598a979d510a783f1d6f097f560f23de997c88;hp=6e772c6b344ecefc66181919174a54fbf1be6e9a;hpb=dc2155083a90de90e24f5341b837d4d96ce2898c;p=8sync.git diff --git a/8sync/actors.scm b/8sync/actors.scm index 6e772c6..ceb2980 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. ;;; @@ -25,6 +25,7 @@ #:use-module (ice-9 match) #:use-module (ice-9 pretty-print) #:use-module (8sync agenda) + #:use-module (8sync rmeta-slot) #:export (;; utilities... ought to go in their own module big-random-number big-random-number-string @@ -51,14 +52,14 @@ 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 @@ -73,7 +74,7 @@ <- <-* <-wait <-wait* <-reply <-reply* <-reply-wait <-reply-wait* - call-with-message msg-receive msg-val + call-with-message mbody-receive mbody-val run-hive bootstrap-message @@ -233,8 +234,9 @@ (define (<-reply original-message . message-body-args) "Reply to a message" - (send-message '() (%current-actor) (message-from original-message) '*reply* - original-message #f message-body-args)) + (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" @@ -243,7 +245,8 @@ (send-message send-options actor (message-from original-message) '*reply* original-message #f message-body-args)) - (apply really-send send-options)) + (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!" @@ -252,10 +255,12 @@ (define (<-reply-wait original-message . message-body-args) "Reply to a messsage, but wait until we get a response" - (wait-maybe-handle-errors - (send-message '() (%current-actor) - (message-from original-message) '*reply* - original-message #t message-body-args))) + (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) @@ -267,7 +272,8 @@ (message-from original-message) '*reply* original-message #t message-body-args) send-options)) - (apply really-send send-options)) + (when (message-needs-reply? original-message) + (apply really-send send-options))) (define* (wait-maybe-handle-errors message #:key accept-errors @@ -289,34 +295,25 @@ raise an exception if an error." (define (actor-inheritable-message-handler actor message) (define action (message-action message)) - (define (find-message-handler return) - (for-each (lambda (this-class) - (define actions - (or (and (class-slot-definition this-class 'actions) - (class-slot-ref this-class 'actions)) - '())) - (for-each (match-lambda - ((action-name . method) - (when (eq? action-name action) - (return method)))) - actions)) - (class-precedence-list (class-of actor))) + (define method + (class-rmeta-ref (class-of actor) 'actions action + #:equals? eq? #:cache-set! hashq-set! + #:cache-ref hashq-ref)) + (unless method (throw 'action-not-found "No appropriate action handler found for actor" #:action action #:actor actor #:message message)) - (define method - (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)) ...)) + (build-rmeta-slot + (list (cons (quote symbol) + (wrap-apply method)) ...))) (define-class () ;; An address object @@ -334,28 +331,24 @@ to come after class definition." #: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 (build-actions + (actions #:init-thunk (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)) -;;; 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) (vector actor-id hive-id)) @@ -393,10 +386,13 @@ to come after class definition." ;;; Actor utilities ;;; =============== -(define-syntax-rule (define-simple-actor class action ...) - (define-class class () - (actions #:init-value (build-actions action ...) - #:allocation #:each-subclass))) +(define-syntax-rule (define-actor class inherits + (action ...) + slots ...) + (define-class class inherits + (actions #:init-thunk (build-actions action ...) + #:allocation #:each-subclass) + slots ...)) ;;; The Hive @@ -428,22 +424,45 @@ to come after class definition." (prompt #:init-thunk make-prompt-tag #:getter hive-prompt) (actions #:allocation #:each-subclass - #:init-value + #:init-thunk (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) + ;; 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." - ;; Unfortunately we have to do this hack and run over the list + ;; We have to do this hack and run over the list ;; twice, because hash-for-each would result in an unrewindable - ;; continuation. + ;; 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))) @@ -543,7 +562,9 @@ to come after class definition." message)) actor)) - (define (call-catching-coroutine thunk) + ;; TODO: I'm pretty sure we're building up another stack of prompts here + ;; with the way we're doing this. That's a real problem. + (define* (call-catching-coroutine thunk #:optional (catch-errors #t)) (define queued-error-handling-thunk #f) (define (call-catching-errors) ;; TODO: maybe parameterize (or attach to hive) and use @@ -572,7 +593,9 @@ to come after class definition." (if queued-error-handling-thunk (8sync (queued-error-handling-thunk)))) (call-with-prompt (hive-prompt hive) - call-catching-errors + (if catch-errors + call-catching-errors + thunk) (lambda (kont actor message send-options) ;; Register the coroutine (hash-set! (hive-waiting-coroutines hive) @@ -622,7 +645,9 @@ to come after class definition." result)) (#f (throw 'no-waiting-coroutine "message in-reply-to tries to resume nonexistent coroutine" - message)))))) + message)))) + ;; no need to catch errors here, there's already an error handler + #f)) ;; Unhandled action for a reply! (else (throw 'hive-unresumable-coroutine @@ -658,52 +683,61 @@ 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) - "Create an actor on HIVE using ACTOR-CLASS passing in INIT args" +(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 (symbol->string (class-name actor-class)))) + 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." @@ -716,22 +750,22 @@ 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)) @@ -750,15 +784,32 @@ its '*cleanup* action handler." ;;; ========================= (define* (run-hive hive initial-tasks - #:key (cleanup #t)) - "Start up an agenda and run HIVE in it with INITIAL-TASKS." + #:key (cleanup #t) + (handle-signals (list SIGINT SIGTERM))) + "Start up an agenda and run HIVE in it with INITIAL-TASKS. + +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 () - (let* ((queue (list->q initial-tasks)) - (agenda (make-agenda #:pre-unwind-handler print-error-and-continue - #:queue queue))) - (run-agenda agenda))) + (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