glibc/benchtests/bench-arc4random.c

219 lines
5.1 KiB
C

/* arc4random benchmarks.
Copyright (C) 2022-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include "bench-timing.h"
#include "bench-util.h"
#include "json-lib.h"
#include <array_length.h>
#include <intprops.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <support/support.h>
#include <support/timespec.h>
#include <support/xthread.h>
static volatile sig_atomic_t timer_finished;
static void timer_callback (int unused)
{
timer_finished = 1;
}
static timer_t timer;
/* Run for approximately DURATION seconds, and it does not matter who
receive the signal (so not need to mask it on main thread). */
static void
timer_start (void)
{
timer_finished = 0;
timer = support_create_timer (DURATION, 0, false, timer_callback);
}
static void
timer_stop (void)
{
support_delete_timer (timer);
}
static const uint32_t sizes[] = { 0, 16, 32, 48, 64, 80, 96, 112, 128 };
static double
bench_throughput (void)
{
uint64_t n = 0;
struct timespec start, end;
clock_gettime (CLOCK_MONOTONIC, &start);
while (1)
{
DO_NOT_OPTIMIZE_OUT (arc4random ());
n++;
if (timer_finished == 1)
break;
}
clock_gettime (CLOCK_MONOTONIC, &end);
struct timespec diff = timespec_sub (end, start);
double total = (double) n * sizeof (uint32_t);
double duration = (double) diff.tv_sec
+ (double) diff.tv_nsec / TIMESPEC_HZ;
return total / duration;
}
static double
bench_latency (void)
{
timing_t start, stop, cur;
const size_t iters = 1024;
TIMING_NOW (start);
for (size_t i = 0; i < iters; i++)
DO_NOT_OPTIMIZE_OUT (arc4random ());
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
return (double) (cur) / (double) iters;
}
static double
bench_buf_throughput (size_t len)
{
uint8_t buf[len];
uint64_t n = 0;
struct timespec start, end;
clock_gettime (CLOCK_MONOTONIC, &start);
while (1)
{
arc4random_buf (buf, len);
n++;
if (timer_finished == 1)
break;
}
clock_gettime (CLOCK_MONOTONIC, &end);
struct timespec diff = timespec_sub (end, start);
double total = (double) n * len;
double duration = (double) diff.tv_sec
+ (double) diff.tv_nsec / TIMESPEC_HZ;
return total / duration;
}
static double
bench_buf_latency (size_t len)
{
timing_t start, stop, cur;
const size_t iters = 1024;
uint8_t buf[len];
TIMING_NOW (start);
for (size_t i = 0; i < iters; i++)
arc4random_buf (buf, len);
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
return (double) (cur) / (double) iters;
}
static void
bench_singlethread (json_ctx_t *json_ctx)
{
json_element_object_begin (json_ctx);
json_array_begin (json_ctx, "throughput");
for (int i = 0; i < array_length (sizes); i++)
{
timer_start ();
double r = sizes[i] == 0
? bench_throughput () : bench_buf_throughput (sizes[i]);
timer_stop ();
json_element_double (json_ctx, r);
}
json_array_end (json_ctx);
json_array_begin (json_ctx, "latency");
for (int i = 0; i < array_length (sizes); i++)
{
timer_start ();
double r = sizes[i] == 0
? bench_latency () : bench_buf_latency (sizes[i]);
timer_stop ();
json_element_double (json_ctx, r);
}
json_array_end (json_ctx);
json_element_object_end (json_ctx);
}
static void
run_bench (json_ctx_t *json_ctx, const char *name,
char *const*fnames, size_t fnameslen,
void (*bench) (json_ctx_t *ctx))
{
json_attr_object_begin (json_ctx, name);
json_array_begin (json_ctx, "functions");
for (int i = 0; i < fnameslen; i++)
json_element_string (json_ctx, fnames[i]);
json_array_end (json_ctx);
json_array_begin (json_ctx, "results");
bench (json_ctx);
json_array_end (json_ctx);
json_attr_object_end (json_ctx);
}
static int
do_test (void)
{
char *fnames[array_length (sizes)];
for (int i = 0; i < array_length (sizes); i++)
if (sizes[i] == 0)
fnames[i] = xasprintf ("arc4random");
else
fnames[i] = xasprintf ("arc4random_buf(%u)", sizes[i]);
json_ctx_t json_ctx;
json_init (&json_ctx, 0, stdout);
json_document_begin (&json_ctx);
json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
run_bench (&json_ctx, "single-thread", fnames, array_length (fnames),
bench_singlethread);
json_document_end (&json_ctx);
for (int i = 0; i < array_length (sizes); i++)
free (fnames[i]);
return 0;
}
#include <support/test-driver.c>