15 lines
703 B
Racket
15 lines
703 B
Racket
#lang syndicate
|
|
;; Toy file system, based on the example in the ESOP2016 submission.
|
|
;; syndicate/actor implementation, using "during" instead of "on asserted/until retracted".
|
|
|
|
(require/activate "fs-shell.rkt")
|
|
(require/activate "fs-protocol.rkt")
|
|
|
|
(spawn (field [files (hash)])
|
|
(during (observe (file $name _))
|
|
(on-start (printf "At least one reader exists for ~v\n" name))
|
|
(assert (file name (hash-ref (files) name #f)))
|
|
(on-stop (printf "No remaining readers exist for ~v\n" name)))
|
|
(on (message (save (file $name $content))) (files (hash-set (files) name content)))
|
|
(on (message (delete $name)) (files (hash-remove (files) name))))
|