Quick-and-dirty test for timers code.

This commit is contained in:
Nick Mathewson 2016-04-13 15:30:59 -04:00
parent dcf948da06
commit 118556e4b3
4 changed files with 139 additions and 3 deletions

2
.gitignore vendored
View File

@ -180,6 +180,7 @@ uptime-*.json
/src/test/test-memwipe
/src/test/test-ntor-cl
/src/test/test-switch-id
/src/test/test-timers
/src/test/test_workqueue
/src/test/test.exe
/src/test/test-slow.exe
@ -188,6 +189,7 @@ uptime-*.json
/src/test/test-ntor-cl.exe
/src/test/test-memwipe.exe
/src/test/test-switch-id.exe
/src/test/test-timers.exe
/src/test/test_workqueue.exe
/src/test/test_zero_length_keys.sh
/src/test/test_ntor.sh

View File

@ -79,12 +79,23 @@ static struct event *global_timer_event = NULL;
/** We need to choose this value carefully. Because we're using timer wheels,
* it actually costs us to have extra resolution we don't use. So for now,
* I'm going to define our resolution as .1 msec, and hope that's good enough.
*
* Note that two of the most popular libevent backends (epoll without timerfd,
* and windows select), simply can't support sub-millisecond resolution,
* do this is optimistic for a lot of users.
*/
#define USEC_PER_TICK 100
/** One million microseconds in a second */
#define USEC_PER_SEC 1000000
/** Check at least once every N seconds. */
#define MIN_CHECK_SECONDS 3600
/** Check at least once every N ticks. */
#define MIN_CHECK_TICKS \
(((timeout_t)MIN_CHECK_SECONDS) * (1000000 / USEC_PER_TICK))
/**
* Convert the timeval in <b>tv</b> to a timeout_t, and return it.
*
@ -135,8 +146,10 @@ libevent_timer_reschedule(void)
tor_gettimeofday_cached_monotonic(&now);
timer_advance_to_cur_time(&now);
const timeout_t delay = timeouts_timeout(global_timeouts);
timeout_t delay = timeouts_timeout(global_timeouts);
struct timeval d;
if (delay > MIN_CHECK_TICKS)
delay = MIN_CHECK_TICKS;
timeout_to_tv(delay, &d);
event_add(global_timer_event, &d);
}
@ -153,6 +166,7 @@ libevent_timer_callback(evutil_socket_t fd, short what, void *arg)
(void)arg;
struct timeval now;
tor_gettimeofday_cache_clear();
tor_gettimeofday_cached_monotonic(&now);
timer_advance_to_cur_time(&now);
@ -187,6 +201,8 @@ timers_initialize(void)
-1, 0, libevent_timer_callback, NULL);
tor_assert(timer_event);
global_timer_event = timer_event;
libevent_timer_reschedule();
}
/**
@ -253,12 +269,15 @@ timer_schedule(tor_timer_t *t, const struct timeval *tv)
tor_gettimeofday_cached_monotonic(&now);
timer_advance_to_cur_time(&now);
/* Take the old timeout value. */
timeout_t to = timeouts_timeout(global_timeouts);
timeouts_add(global_timeouts, t, when);
/* Should we update the libevent timer? */
if (to <= when) {
return; /* we're already going to fire before this timer would trigger. */
}
libevent_timer_reschedule();
}

View File

@ -17,6 +17,7 @@ endif
TESTS += src/test/test src/test/test-slow src/test/test-memwipe \
src/test/test_workqueue src/test/test_keygen.sh \
src/test/test-timers \
$(TESTSCRIPTS)
# These flavors are run using automake's test-driver and test-network.sh
@ -40,7 +41,8 @@ noinst_PROGRAMS+= \
src/test/test-memwipe \
src/test/test-child \
src/test/test_workqueue \
src/test/test-switch-id
src/test/test-switch-id \
src/test/test-timers
endif
src_test_AM_CPPFLAGS = -DSHARE_DATADIR="\"$(datadir)\"" \
@ -127,6 +129,8 @@ src_test_test_slow_SOURCES = \
src_test_test_memwipe_SOURCES = \
src/test/test-memwipe.c
src_test_test_timers_SOURCES = \
src/test/test-timers.c
src_test_test_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
@ -190,6 +194,16 @@ src_test_test_workqueue_LDADD = src/or/libtor-testing.a \
@TOR_ZLIB_LIBS@ @TOR_LIB_MATH@ @TOR_LIBEVENT_LIBS@ \
@TOR_OPENSSL_LIBS@ @TOR_LIB_WS32@ @TOR_LIB_GDI@ @CURVE25519_LIBS@
src_test_test_timers_CPPFLAGS = $(src_test_test_CPPFLAGS)
src_test_test_timers_CFLAGS = $(src_test_test_CFLAGS)
src_test_test_timers_LDADD = \
src/common/libor-event-testing.a \
src/common/libor-crypto-testing.a $(LIBKECCAK_TINY) $(LIBDONNA) \
src/common/libor-testing.a \
@TOR_ZLIB_LIBS@ @TOR_LIB_MATH@ @TOR_LIBEVENT_LIBS@ \
@TOR_OPENSSL_LIBS@ @TOR_LIB_WS32@ @TOR_LIB_GDI@ @CURVE25519_LIBS@
src_test_test_timers_LDFLAGS = $(src_test_test_LDFLAGS)
noinst_HEADERS+= \
src/test/fakechans.h \
src/test/log_test_helpers.h \

101
src/test/test-timers.c Normal file
View File

@ -0,0 +1,101 @@
/* 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
static struct timeval fire_at[N_TIMERS] = {{0,0}};
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_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_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;
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], 0);
timer_schedule(timers[i], &delay);
}
event_base_loop(tor_libevent_get_base(), 0);
uint64_t total_difference = 0;
uint64_t total_square_difference = 0;
tor_assert(n_fired == N_TIMERS);
for (i = 0; i < N_TIMERS; ++i) {
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_TIMERS;
printf("mean difference: "U64_FORMAT" usec\n",
U64_PRINTF_ARG(mean_diff));
const double mean_sq = ((double)total_square_difference) / N_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");
return 1;
} else if (mean_diff > 2000 || stddev > 2000) {
printf("Either your system is a bit slow or the "
"timer backend is odd.\n");
return 0;
} else {
printf("Looks good enough.\n");
}
return 0;
}