racket/collects/tests/stress.rkt
2011-06-28 02:01:41 -04:00

95 lines
3.0 KiB
Racket

#lang racket
(provide stress
fit)
; fit : string number (number -> any) #:slices number -> void
; Run f with slices different numbers between 0 and max, then print the summary
; timing with label
(define (fit label max f #:slices [slices 20])
(fit-display
label
(for/list ([slice-n (in-range 1 (add1 slices))])
(define i (round (* slice-n (/ max slices))))
(define-values (cpu real gc)
(isolate slice-n (λ () (f i))))
(collect-garbage) (collect-garbage)
(vector i cpu))))
(define (fit-display label l)
(define baseline (vector-ref (findf (λ (v) (not (zero? (vector-ref v 1)))) l) 1))
(printf "~a: baseline = ~a\n" label baseline)
(for ([v (in-list l)])
(match-define (vector n val) v)
(printf "\t~a: ~ax\n" n (exact->inexact (/ val baseline)))))
(define (isolate trial-n thunk)
(define exp-cust (make-custodian))
(define-values (_ cpu real gc)
(parameterize ([current-custodian exp-cust])
(time-apply thunk empty)))
(custodian-shutdown-all exp-cust)
(values cpu real gc))
; stress : number [string expr ...] ...
; Runs trials-expr different instances of each (begin expr ...) averaging the
; timing and displaying them sorted by cpu time
(define-syntax-rule (stress trials-expr [label body ...] ...)
(stress* trials-expr
(cons label (λ () body ...))
...))
(define (cumulative-average ca x i)
(+ ca (/ (- x ca) (add1 i))))
(define (run-experiment how-many exp)
(match-define (cons label thunk) exp)
(define-values
(cpu real gc)
(for/fold ([cpu0 0.0]
[real0 0.0]
[gc0 0.0])
([trial-n (in-range how-many)])
(define-values (cpu1 real1 gc1)
(isolate trial-n thunk))
(when (zero? (modulo trial-n 5))
(collect-garbage) (collect-garbage))
(values (cumulative-average cpu0 cpu1 trial-n)
(cumulative-average real0 real1 trial-n)
(cumulative-average gc0 gc1 trial-n))))
(vector label cpu real gc))
(define (stress* how-many . experiments)
(stress-display
how-many
(sort-experiments
(for/list ([exp (in-list experiments)])
(run-experiment how-many exp)))))
(define (sort-experiments l)
(sort l <=
#:key (λ (v) (vector-ref v 1))))
(define (stress-display how-many res)
(define-values
(min-cpu min-real min-gc)
(for/fold ([min-cpu +inf.0]
[min-real +inf.0]
[min-gc +inf.0])
([v (in-list res)])
(match-define (vector label cpu real gc) v)
(printf "~a: cpu: ~a real: ~a gc: ~a (averaged over ~a runs)\n"
label cpu real gc how-many)
(values (min min-cpu cpu)
(min min-real real)
(min min-gc gc))))
(define (norm min x)
(if (zero? min)
"inf"
(real->decimal-string (/ x min))))
(printf "Normalized:\n")
(for ([v (in-list res)])
(match-define (vector label cpu real gc) v)
(printf "~a: cpu: ~a real: ~a gc: ~a (averaged over ~a runs)\n"
label (norm min-cpu cpu) (norm min-real real) (norm min-gc gc) how-many))
(newline))