-(define-module (loopy agenda)
+;; Copyright (C) 2015 Christopher Allan Webber <cwebber@dustycloud.org>
+
+;; 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)
schedule-segments-split schedule-extract-until!
add-segments-contents-to-queue!
+ %sync 8sync
+
<run-request>
make-run-request run-request?
run-request-proc run-request-when
- run-it wrap run run-at delay
+ <port-request>
+ 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))
(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
(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))))
+
\f
;;; Schedule
(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 <time-delta> 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)
(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)))))
(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)
;; 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
(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)
segments))
-\f
-;;; 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)))
-
-
\f
;;; Request to run stuff
;;; ====================
-(define-immutable-record-type <run-request>
+(define-record-type <run-request>
(make-run-request proc when)
run-request?
(proc run-request-proc)
(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))
"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 <port-request>
+ (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)
+
+
+\f
+;;; 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 ...))
+
\f
;;; Execution of agenda, and current agenda
(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)
(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
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)))
(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
projects / 8sync.git / blobdiff