X-Git-Url: https://jxself.org/git/?p=8sync.git;a=blobdiff_plain;f=loopy.scm;h=8ffe6f18a489a94520f0a1058f0d9a8e3ca1da8a;hp=cc1ee7889bcfdcb1a253b0ec0049c84a3a730890;hb=302b13a687285471ba67d62553639519adfb4da8;hpb=bbbf61a9bb88a9a97f987a67f7e06e0febbf0d53 diff --git a/loopy.scm b/loopy.scm index cc1ee78..8ffe6f1 100644 --- a/loopy.scm +++ b/loopy.scm @@ -1,4 +1,21 @@ -(define-module (loopy agenda) +;; Copyright (C) 2015 Christopher Allan Webber + +;; This library is free software; you can redistribute it and/or +;; modify it under the terms of the GNU Lesser General Public +;; License as published by the Free Software Foundation; either +;; version 3 of the License, or (at your option) any later version. +;; +;; This library is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +;; Lesser General Public License for more details. +;; +;; You should have received a copy of the GNU Lesser General Public +;; License along with this library; if not, write to the Free Software +;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +;; 02110-1301 USA + +(define-module (eightsync agenda) #:use-module (srfi srfi-1) #:use-module (srfi srfi-9) #:use-module (srfi srfi-9 gnu) @@ -33,12 +50,22 @@ schedule-segments-split schedule-extract-until! add-segments-contents-to-queue! + %sync 8sync + make-run-request run-request? run-request-proc run-request-when - run-it wrap run run-at delay + + make-port-request port-request port-request? + port-request-port + port-request-read port-request-write port-request-except + + run-it wrap run run-at run-delay + %port-request %run %run-at %run-delay + 8port-request 8run 8run-at 8run-delay + %current-agenda start-agenda agenda-run-once)) @@ -77,6 +104,9 @@ (time agenda-time)) (define (make-async-prompt-tag) + "Make an async prompt tag for an agenda. + +Generally done automatically for the user through (make-agenda)." (make-prompt-tag "prompt")) (define* (make-agenda #:key @@ -87,10 +117,21 @@ (except-port-map (make-hash-table)) (schedule (make-schedule)) (time (gettimeofday))) + ;; TODO: document arguments + "Make a fresh agenda." (make-agenda-intern queue prompt read-port-map write-port-map except-port-map schedule time)) +(define (current-agenda-prompt) + "Get the prompt for the current agenda; signal an error if there isn't one." + (let ((current-agenda (%current-agenda))) + (if (not current-agenda) + (throw + 'no-current-agenda + "Can't get current agenda prompt if there's no current agenda!") + (agenda-prompt-tag current-agenda)))) + ;;; Schedule @@ -158,12 +199,12 @@ run (time-segment-right-format) first." (sec time-delta-sec) (usec time-delta-usec)) -(define* (make-time-delta sec #:optional usec) +(define* (make-time-delta sec #:optional (usec 0)) "Make a of SEC seconds and USEC microseconds. This is used primarily so the agenda can recognize RUN-REQUEST objects which are meant " - (make-time-delta-intern sec (or usec 0))) + (make-time-delta-intern sec usec)) (define tdelta make-time-delta) @@ -183,16 +224,19 @@ Will produce (0 . 0) instead of a negative number, if needed." (else time))) (define (time-delta+ time time-delta) + "Increment a TIME by the value of TIME-DELTA" (time-carry-correct (cons (+ (car time) (time-delta-sec time-delta)) (+ (cdr time) (time-delta-usec time-delta))))) (define (time-minus time1 time2) + "Subtract TIME2 from TIME1" (time-carry-correct (cons (- (car time1) (car time2)) (- (cdr time2) (cdr time2))))) (define (time-plus time1 time2) + "Add TIME1 and TIME2" (time-carry-correct (cons (+ (car time1) (car time2)) (+ (cdr time2) (cdr time2))))) @@ -204,6 +248,7 @@ Will produce (0 . 0) instead of a negative number, if needed." (segments schedule-segments set-schedule-segments!)) (define* (make-schedule #:optional segments) + "Make a schedule, optionally pre-composed of SEGMENTS" (make-schedule-intern (or segments '()))) (define (schedule-soonest-time schedule) @@ -218,6 +263,7 @@ Will produce (0 . 0) instead of a negative number, if needed." ;; but at least it'll be reasonably easy to refactor to ;; a more functional setup? (define (schedule-add! schedule time proc) + "Mutate SCHEDULE, adding PROC at an appropriate time segment for TIME" (let ((time (time-segment-right-format time))) (define (new-time-segment) (let ((new-segment @@ -255,6 +301,7 @@ Will produce (0 . 0) instead of a negative number, if needed." (loop (schedule-segments schedule))))) (define (schedule-empty? schedule) + "Check if the SCHEDULE is currently empty" (eq? (schedule-segments schedule) '())) (define (schedule-segments-split schedule time) @@ -301,41 +348,11 @@ Will produce (0 . 0) instead of a negative number, if needed." segments)) - -;;; Port handling -;;; ============= - -(define (make-port-mapping) - (make-hash-table)) - -(define* (port-mapping-set! port-mapping port #:optional read write except) - "Sets port-mapping for reader / writer / exception handlers" - (if (not (or read write except)) - (throw 'no-handlers-given "No handlers given for port" port)) - (hashq-set! port-mapping port - `#(,read ,write ,except))) - -(define (port-mapping-remove! port-mapping port) - (hashq-remove! port-mapping port)) - -;; TODO: This is O(n), I'm pretty sure :\ -;; ... it might be worthwhile for us to have a -;; port-mapping record that keeps a count of how many -;; handlers (maybe via a promise?) -(define (port-mapping-empty? port-mapping) - "Is this port mapping empty?" - (eq? (hash-count (const #t) port-mapping) 0)) - -(define (port-mapping-non-empty? port-mapping) - "Whether this port-mapping contains any elements" - (not (port-mapping-empty? port-mapping))) - - ;;; Request to run stuff ;;; ==================== -(define-immutable-record-type +(define-record-type (make-run-request proc when) run-request? (proc run-request-proc) @@ -350,6 +367,8 @@ Will produce (0 . 0) instead of a negative number, if needed." (lambda () body ...)) +;; @@: Do we really want `body ...' here? +;; what about just `body'? (define-syntax-rule (run body ...) "Run everything in BODY but wrap in a convenient procedure" (make-run-request (wrap body ...) #f)) @@ -358,15 +377,137 @@ Will produce (0 . 0) instead of a negative number, if needed." "Run BODY at WHEN" (make-run-request (wrap body ...) when)) +;; @@: Is it okay to overload the term "delay" like this? +;; Would `run-in' be better? (define-syntax-rule (run-delay body ... delay-time) "Run BODY at DELAY-TIME time from now" (make-run-request (wrap body ...) (tdelta delay-time))) -(define (delay run-request delay-time) - "Delay a RUN-REQUEST by DELAY-TIME" - (set-field run-request - (run-request-when) - (tdelta delay-time))) + +;; A request to set up a port with at least one of read, write, except +;; handling processes + +(define-record-type + (make-port-request-intern port read write except) + port-request? + (port port-request-port) + (read port-request-read) + (write port-request-write) + (except port-request-except)) + +(define* (make-port-request port #:key read write except) + (if (not (or read write except)) + (throw 'no-port-handler-given "No port handler given.\n")) + (make-port-request-intern port read write except)) + +(define port-request make-port-request) + + + +;;; Asynchronous escape to run things +;;; ================================= + +;; The future's in futures + +(define (make-future call-first on-success on-fail on-error) + ;; TODO: add error stuff here + (lambda () + (let ((call-result (call-first))) + ;; queue up calling the + (run (on-success call-result))))) + +(define (agenda-on-error agenda) + (const #f)) + +(define (agenda-on-fail agenda) + (const #f)) + +(define* (request-future call-first on-success + #:key + (agenda (%current-agenda)) + (on-fail (agenda-on-fail agenda)) + (on-error (agenda-on-error agenda)) + (when #f)) + ;; TODO: error handling + ;; do we need some distinction between expected, catchable errors, + ;; and unexpected, uncatchable ones? Probably...? + (make-run-request + (make-future call-first on-success on-fail on-error) + when)) + +(define-syntax-rule (%sync async-request) + "Run BODY asynchronously at a prompt, passing args to make-future. + +Pronounced `eight-sync' despite the spelling. + +%sync was chosen because (async) was already taken and could lead to +errors, and this version of asynchronous code uses a prompt, so the `a' +character becomes a `%' prompt! :) + +The % and 8 characters kind of look similar... hence this library's +name! (That, and the pun 'eight-synchronous' programming.) +There are 8sync aliases if you prefer that name." + (abort-to-prompt (current-agenda-prompt) + async-request)) + +(define-syntax-rule (8sync args ...) + "Alias for %sync" + (%sync args ...)) + +;; Async port request and run-request meta-requests +(define (make-async-request proc) + "Wrap PROC in an async-request + +The purpose of this is to make sure that users don't accidentally +return the wrong thing via (8sync) and trip themselves up." + (cons '*async-request* proc)) + +(define (setup-async-request resume-kont async-request) + "Complete an async request for agenda-run-once's continuation handling" + (match async-request + (('*async-request* . async-setup-proc) + (async-setup-proc resume-kont)) + ;; TODO: deliver more helpful errors depending on what the user + ;; returned + (_ (throw 'invalid-async-request + "Invalid request passed back via an (%sync) procedure." + async-request)))) + +(define-syntax-rule (%run body ...) + (%run-at body ... #f)) + +(define-syntax-rule (%run-at body ... when) + (make-async-request + (lambda (kont) + (make-run-request + (wrap + (kont + (begin body ...))) + when)))) + +(define-syntax-rule (%run-delay body ... delay-time) + (%run-at body ... (tdelta delay-time))) + +(define-syntax-rule (%port-request add-this-port port-request-args ...) + (make-async-request + (lambda (kont) + (list (make-port-request port-request-args ...) + (make-run-request kont))))) + +;; TODO +(define-syntax-rule (%run-with-return return body ...) + (make-async-request + (lambda (kont) + (let ((return kont)) + (lambda () + body ...))))) + +;; Aliases +(define-syntax-rule (8run args ...) (%run args ...)) +(define-syntax-rule (8run-at args ...) (%run-at args ...)) +(define-syntax-rule (8run-delay args ...) (%run-delay args ...)) +(define-syntax-rule (8port-request args ...) (%port-request args ...)) + ;;; Execution of agenda, and current agenda @@ -375,6 +516,7 @@ Will produce (0 . 0) instead of a negative number, if needed." (define %current-agenda (make-parameter #f)) (define (update-agenda-from-select! agenda) + "Potentially (select) on ports specified in agenda, adding items to queue" (define (hash-keys hash) (hash-map->list (lambda (k v) k) hash)) (define (get-wait-time) @@ -448,18 +590,30 @@ Will produce (0 . 0) instead of a negative number, if needed." (update-agenda) agenda)) +(define (agenda-handle-port-request! agenda port-request) + "Update an agenda for a port-request" + (define (handle-selector request-selector port-map-selector) + (if (request-selector port-request) + (hash-set! (port-map-selector agenda) + (port-request-port port-request) + (request-selector port-request)))) + (handle-selector port-request-read agenda-read-port-map) + (handle-selector port-request-write agenda-write-port-map) + (handle-selector port-request-except agenda-except-port-map)) + (define* (start-agenda agenda #:key stop-condition (get-time gettimeofday) (handle-ports update-agenda-from-select!)) + ;; TODO: Document fields + "Start up the AGENDA" (let loop ((agenda agenda)) (let ((agenda ;; @@: Hm, maybe here would be a great place to handle ;; select'ing on ports. ;; We could compose over agenda-run-once and agenda-read-ports - (parameterize ((%current-agenda agenda)) - (agenda-run-once agenda)))) + (agenda-run-once agenda))) (if (and stop-condition (stop-condition agenda)) 'done (let* ((agenda @@ -484,11 +638,12 @@ Will produce (0 . 0) instead of a negative number, if needed." based on the results" (define (call-proc proc) (call-with-prompt - (agenda-prompt-tag agenda) - (lambda () - (proc)) - ;; TODO - (lambda (k) k))) + (agenda-prompt-tag agenda) + (lambda () + (parameterize ((%current-agenda agenda)) + (proc))) + (lambda (kont async-request) + (setup-async-request kont async-request)))) (let ((queue (agenda-queue agenda)) (next-queue (make-q))) @@ -512,19 +667,19 @@ based on the results" (schedule-at! request-time (run-request-proc run-request))) (#f (enq! next-queue (run-request-proc run-request)))))))) + (define (handle-individual result) + (match result + ((? run-request? new-proc) + (enqueue new-proc)) + ((? port-request? port-request) + (agenda-handle-port-request! agenda port-request)) + ;; do nothing + (_ #f))) ;; @@: We might support delay-wrapped procedures here (match proc-result - ;; TODO: replace procedure with something that indicates - ;; intent to run. Use a (run foo) procedure - ((? run-request? new-proc) - (enqueue new-proc)) - (((? run-request? new-procs) ...) - (for-each - (lambda (new-proc) - (enqueue new-proc)) - new-procs)) - ;; do nothing - (_ #f)))) + ((results ...) + (for-each handle-individual results)) + (one-result (handle-individual one-result))))) ;; TODO: Alternately, we could return the next-queue ;; along with changes to be added to the schedule here? ;; Return new agenda, with next queue set