98 lines
2.7 KiB
Racket
98 lines
2.7 KiB
Racket
#lang racket/base
|
|
;; Measurement of message delivery latency.
|
|
|
|
(require racket/match)
|
|
(require minimart)
|
|
(require logbook)
|
|
|
|
(struct ping (src dst timestamp) #:transparent)
|
|
|
|
(define (send-ping src dst)
|
|
(send (ping src dst (current-inexact-milliseconds))))
|
|
|
|
(define (run #:echoer-count [echoer-count 100]
|
|
#:run-time [run-time 10000])
|
|
(define total-latency 0)
|
|
(define total-roundtrips 0)
|
|
(define boot-start-time (current-inexact-milliseconds))
|
|
(define run-start-time #f)
|
|
|
|
(define (rate-at count)
|
|
(/ (* count 2) ;; two messages per roundtrip
|
|
(/ total-latency 1000.0) ;; latency in seconds
|
|
))
|
|
|
|
(define (pinger src dst)
|
|
(spawn (lambda (e s)
|
|
(match e
|
|
[(message 'kickoff _ _)
|
|
(set! run-start-time (current-inexact-milliseconds))
|
|
(transition s (send-ping src dst))]
|
|
[(message (ping (== dst) (== src) start-time) _ _)
|
|
(define stop-time (current-inexact-milliseconds))
|
|
(define delta (- stop-time start-time))
|
|
(set! total-latency (+ total-latency delta))
|
|
(set! total-roundtrips (+ total-roundtrips 1))
|
|
(when (zero? (modulo total-roundtrips 1000))
|
|
(log-info "After ~a roundtrips, ~a milliseconds; ~a Hz"
|
|
total-roundtrips
|
|
total-latency
|
|
(rate-at total-roundtrips)))
|
|
(transition s
|
|
(if (< (- stop-time run-start-time) run-time)
|
|
(send-ping src dst)
|
|
'()))]
|
|
[_ #f]))
|
|
#f
|
|
(list (sub (ping dst src ?))
|
|
(sub 'kickoff)
|
|
(pub (ping src dst ?)))))
|
|
|
|
(define (echoer id)
|
|
(spawn (lambda (e s)
|
|
(match e
|
|
[(message (ping src (== id) stamp) _ _)
|
|
(transition s (send (ping id src stamp)))]
|
|
[_ #f]))
|
|
#f
|
|
(list (sub (ping ? id ?))
|
|
(pub (ping id ? ?)))))
|
|
|
|
(begin
|
|
(run-ground (for/list [(id (in-range echoer-count))] (echoer id))
|
|
(pinger echoer-count 0)
|
|
(send 'kickoff))
|
|
(values total-roundtrips (rate-at total-roundtrips) (- run-start-time boot-start-time))))
|
|
|
|
(module+ main
|
|
(define t 5000)
|
|
(define E (standard-logbook-entry (default-logbook #:verbose? #t) "minimart"))
|
|
(define T (logbook-table E "internal-latency"
|
|
#:column-spec '(number-of-echoers
|
|
secs/msg
|
|
msgs/sec
|
|
boot-delay-ms
|
|
roundtrip-count
|
|
run-duration-ms)))
|
|
;; Warmup
|
|
(let ()
|
|
(run #:echoer-count 1 #:run-time 1000)
|
|
(run #:echoer-count 10 #:run-time 1000)
|
|
(void))
|
|
;; Real run
|
|
(for ((n
|
|
(list 1 10 20 30 40 50 60 70 80 90 100 120
|
|
150 200 210 220 230 240 250 260 270 280 290 300 400
|
|
500 600 700 800 900)
|
|
))
|
|
(collect-garbage)
|
|
(collect-garbage)
|
|
(collect-garbage)
|
|
(define-values (count v boot-delay-ms) (run #:echoer-count n #:run-time t))
|
|
(write-logbook-datum! T (list n
|
|
(/ 1.0 v)
|
|
v
|
|
boot-delay-ms
|
|
count
|
|
t))))
|