28 lines
843 B
Racket
28 lines
843 B
Racket
|
#lang syndicate
|
||
|
|
|
||
|
|
(require syndicate/actor)
|
||
|
|
(require syndicate/drivers/timer)
|
||
|
|
(require syndicate/drivers/udp)
|
||
|
|
(require racket/random file/sha1)
|
||
|
|
|
||
|
|
(spawn-timer-driver)
|
||
|
|
(spawn-udp-driver)
|
||
|
|
|
||
|
|
(actor (define me (bytes->hex-string (crypto-random-bytes 8)))
|
||
|
|
(define h (udp-listener 5999))
|
||
|
|
|
||
|
|
(define (rearm!) (send! (set-timer h 1000 'relative)))
|
||
|
|
|
||
|
|
(rearm!)
|
||
|
|
|
||
|
|
(forever
|
||
|
|
(assert (udp-multicast-group-member h "224.0.0.251" #f))
|
||
|
|
(assert (udp-multicast-loopback h #t))
|
||
|
|
(on (message (udp-packet $source h $body))
|
||
|
|
(printf "~a: ~a\n" source body))
|
||
|
|
(on (message (timer-expired h $now))
|
||
|
|
(rearm!)
|
||
|
|
(send! (udp-packet h
|
||
|
|
(udp-remote-address "224.0.0.251" 5999)
|
||
|
|
(string->bytes/utf-8 (format "~a ~a" me now)))))))
|