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/* Copyright 2016, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#include "orconfig.h"
#include <math.h>
#include <stdio.h>
#include <string.h>
#ifdef HAVE_EVENT2_EVENT_H
#include <event2/event.h>
#else
#include <event.h>
#endif
#include "compat.h"
#include "compat_libevent.h"
#include "crypto.h"
#include "timers.h"
#include "util.h"
#define N_TIMERS 1000
#define MAX_DURATION 30
#define N_DISABLE 5
static struct timeval fire_at[N_TIMERS] = {{0,0}};
static int is_disabled[N_TIMERS] = {0};
static int fired[N_TIMERS] = {0};
static struct timeval difference[N_TIMERS] = {{0,0}};
static tor_timer_t *timers[N_TIMERS] = {NULL};
static int n_active_timers = 0;
static int n_fired = 0;
static void
timer_cb(tor_timer_t *t, void *arg, const struct timeval *now)
{
tor_timer_t **t_ptr = arg;
tor_assert(*t_ptr == t);
int idx = (int) (t_ptr - timers);
++fired[idx];
timersub(now, &fire_at[idx], &difference[idx]);
++n_fired;
// printf("%d / %d\n",n_fired, N_TIMERS);
if (n_fired == n_active_timers) {
event_base_loopbreak(tor_libevent_get_base());
}
}
int
main(int argc, char **argv)
{
(void)argc;
(void)argv;
tor_libevent_cfg cfg;
memset(&cfg, 0, sizeof(cfg));
tor_libevent_initialize(&cfg);
timers_initialize();
int i;
int ret;
struct timeval now;
tor_gettimeofday(&now);
for (i = 0; i < N_TIMERS; ++i) {
struct timeval delay;
delay.tv_sec = crypto_rand_int_range(0,MAX_DURATION);
delay.tv_usec = crypto_rand_int_range(0,1000000);
timeradd(&now, &delay, &fire_at[i]);
timers[i] = timer_new(timer_cb, &timers[i]);
timer_schedule(timers[i], &delay);
++n_active_timers;
}
/* Disable some; we'll make sure they don't trigger. */
for (i = 0; i < N_DISABLE; ++i) {
int idx = crypto_rand_int_range(0, N_TIMERS);
if (is_disabled[idx])
continue;
is_disabled[idx] = 1;
timer_disable(timers[idx]);
--n_active_timers;
}
event_base_loop(tor_libevent_get_base(), 0);
uint64_t total_difference = 0;
uint64_t total_square_difference = 0;
tor_assert(n_fired == n_active_timers);
for (i = 0; i < N_TIMERS; ++i) {
if (is_disabled[i]) {
tor_assert(fired[i] == 0);
continue;
}
tor_assert(fired[i] == 1);
uint64_t diff = difference[i].tv_usec + difference[i].tv_sec * 1000000;
total_difference += diff;
total_square_difference += diff*diff;
}
const uint64_t mean_diff = total_difference / n_active_timers;
printf("mean difference: "U64_FORMAT" usec\n",
U64_PRINTF_ARG(mean_diff));
const double mean_sq = ((double)total_square_difference)/ n_active_timers;
const double sq_mean = mean_diff * mean_diff;
const double stddev = sqrt(mean_sq - sq_mean);
printf("standard deviation: %lf usec\n", stddev);
if (mean_diff > 500*1000 || stddev > 500*1000) {
printf("Either your system is under ridiculous load, or the "
"timer backend is broken.\n");
ret = 1;
} else if (mean_diff > 2000 || stddev > 2000) {
printf("Either your system is a bit slow or the "
"timer backend is odd.\n");
ret = 0;
} else {
printf("Looks good enough.\n");
ret = 0;
}
timer_free(NULL);
for (i = 0; i < N_TIMERS; ++i) {
timer_free(timers[i]);
}
timers_shutdown();
return ret;
}
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