28 lines
1.0 KiB
Racket
28 lines
1.0 KiB
Racket
#lang prospect
|
|
;; Test case for a historical bug in Syndicate.
|
|
;;
|
|
;; When the bug existed, this program received four SCN events in
|
|
;; total, whereas it should receive only two.
|
|
;;
|
|
;; While metamessages were "echo cancelled", and receivers only ever
|
|
;; got one copy of a sent metamessage no matter how many metas there
|
|
;; were, state changes were not. Issuing a quick enough "pulse" of
|
|
;; metaassertion while maintaining interest in it led to an "echo":
|
|
;; multiple receipts of the pulse.
|
|
;;
|
|
;; The fix was to adjust the implementation of state change
|
|
;; notifications to cancel the echo for metaassertions.
|
|
|
|
(require prospect/pretty)
|
|
|
|
(spawn-network
|
|
(spawn (lambda (e counter)
|
|
(and e
|
|
(let ((new-counter (+ counter 1)))
|
|
(printf "Received event ~a:\n~a\n" new-counter (prospect-pretty-print->string e))
|
|
(transition (+ counter 1) '()))))
|
|
0
|
|
(list (patch-seq (assert (at-meta 'x))
|
|
(sub 'x #:meta-level 1))
|
|
(retract (at-meta 'x)))))
|