xref: /netbsd-src/external/bsd/ntp/dist/sntp/libevent/test/test-ratelim.c (revision eabc0478de71e4e011a5b4e0392741e01d491794)
1 /*	$NetBSD: test-ratelim.c,v 1.8 2024/08/18 20:47:23 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 #include "../util-internal.h"
29 
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <assert.h>
34 #include <math.h>
35 
36 #ifdef _WIN32
37 #include <winsock2.h>
38 #include <ws2tcpip.h>
39 #else
40 #include <sys/socket.h>
41 #include <netinet/in.h>
42 # ifdef _XOPEN_SOURCE_EXTENDED
43 #  include <arpa/inet.h>
44 # endif
45 #endif
46 #include <signal.h>
47 
48 #include "event2/bufferevent.h"
49 #include "event2/buffer.h"
50 #include "event2/event.h"
51 #include "event2/util.h"
52 #include "event2/listener.h"
53 #include "event2/thread.h"
54 
55 #ifndef MIN
56 #define MIN(a,b) (((a)<(b))?(a):(b))
57 #endif
58 
59 static struct evutil_weakrand_state weakrand_state;
60 
61 static int cfg_verbose = 0;
62 static int cfg_help = 0;
63 
64 static int cfg_n_connections = 30;
65 static int cfg_duration = 5;
66 static int cfg_connlimit = 0;
67 static int cfg_grouplimit = 0;
68 static int cfg_tick_msec = 1000;
69 static int cfg_min_share = -1;
70 static int cfg_group_drain = 0;
71 
72 static int cfg_connlimit_tolerance = -1;
73 static int cfg_grouplimit_tolerance = -1;
74 static int cfg_stddev_tolerance = -1;
75 
76 #ifdef _WIN32
77 static int cfg_enable_iocp = 0;
78 #endif
79 
80 static struct timeval cfg_tick = { 0, 500*1000 };
81 
82 static struct ev_token_bucket_cfg *conn_bucket_cfg = NULL;
83 static struct ev_token_bucket_cfg *group_bucket_cfg = NULL;
84 struct bufferevent_rate_limit_group *ratelim_group = NULL;
85 static double seconds_per_tick = 0.0;
86 
87 struct client_state {
88 	size_t queued;
89 	ev_uint64_t received;
90 
91 };
92 static const struct timeval *ms100_common=NULL;
93 
94 /* Timers bias for slow CPUs, affects:
95  * - cfg_connlimit_tolerance  (--check-connlimit)
96  * - cfg_grouplimit_tolerance (--check-grouplimit)
97  * - cfg_stddev_tolerance     (--check-stddev)
98  */
99 static int timer_bias_events;
100 static struct timeval timer_bias_start;
101 double timer_bias_spend;
102 /* Real cost is less (approximately ~5 usec),
103  * this macros adjusted to make the bias less */
104 #define TIMER_MAX_COST_USEC 10
105 
106 /* info from check_bucket_levels_cb */
107 static int total_n_bev_checks = 0;
108 static ev_int64_t total_rbucket_level=0;
109 static ev_int64_t total_wbucket_level=0;
110 static ev_int64_t total_max_to_read=0;
111 static ev_int64_t total_max_to_write=0;
112 static ev_int64_t max_bucket_level=EV_INT64_MIN;
113 static ev_int64_t min_bucket_level=EV_INT64_MAX;
114 
115 /* from check_group_bucket_levels_cb */
116 static int total_n_group_bev_checks = 0;
117 static ev_int64_t total_group_rbucket_level = 0;
118 static ev_int64_t total_group_wbucket_level = 0;
119 
120 static int n_echo_conns_open = 0;
121 
122 /* Info on the open connections */
123 struct bufferevent **bevs;
124 struct client_state *states;
125 struct bufferevent_rate_limit_group *group = NULL;
126 
127 static void check_bucket_levels_cb(evutil_socket_t fd, short events, void *arg);
128 
129 static void
130 loud_writecb(struct bufferevent *bev, void *ctx)
131 {
132 	struct client_state *cs = ctx;
133 	struct evbuffer *output = bufferevent_get_output(bev);
134 	char buf[1024];
135 	int r = evutil_weakrand_(&weakrand_state);
136 	memset(buf, r, sizeof(buf));
137 	while (evbuffer_get_length(output) < 8192) {
138 		evbuffer_add(output, buf, sizeof(buf));
139 		cs->queued += sizeof(buf);
140 	}
141 }
142 
143 static void
144 discard_readcb(struct bufferevent *bev, void *ctx)
145 {
146 	struct client_state *cs = ctx;
147 	struct evbuffer *input = bufferevent_get_input(bev);
148 	size_t len = evbuffer_get_length(input);
149 	evbuffer_drain(input, len);
150 	cs->received += len;
151 }
152 
153 static void
154 write_on_connectedcb(struct bufferevent *bev, short what, void *ctx)
155 {
156 	if (what & BEV_EVENT_CONNECTED) {
157 		loud_writecb(bev, ctx);
158 		/* XXXX this shouldn't be needed. */
159 		bufferevent_enable(bev, EV_READ|EV_WRITE);
160 	}
161 }
162 
163 static void
164 echo_readcb(struct bufferevent *bev, void *ctx)
165 {
166 	struct evbuffer *input = bufferevent_get_input(bev);
167 	struct evbuffer *output = bufferevent_get_output(bev);
168 
169 	evbuffer_add_buffer(output, input);
170 	if (evbuffer_get_length(output) > 1024000)
171 		bufferevent_disable(bev, EV_READ);
172 }
173 
174 static void
175 echo_writecb(struct bufferevent *bev, void *ctx)
176 {
177 	struct evbuffer *output = bufferevent_get_output(bev);
178 	if (evbuffer_get_length(output) < 512000)
179 		bufferevent_enable(bev, EV_READ);
180 }
181 
182 static void
183 echo_eventcb(struct bufferevent *bev, short what, void *ctx)
184 {
185 	if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
186 		--n_echo_conns_open;
187 		bufferevent_free(bev);
188 	}
189 }
190 
191 static void
192 echo_listenercb(struct evconnlistener *listener, evutil_socket_t newsock,
193     struct sockaddr *sourceaddr, int socklen, void *ctx)
194 {
195 	struct event_base *base = ctx;
196 	int flags = BEV_OPT_CLOSE_ON_FREE|BEV_OPT_THREADSAFE;
197 	struct bufferevent *bev;
198 
199 	bev = bufferevent_socket_new(base, newsock, flags);
200 	bufferevent_setcb(bev, echo_readcb, echo_writecb, echo_eventcb, NULL);
201 	if (conn_bucket_cfg) {
202 		struct event *check_event =
203 		    event_new(base, -1, EV_PERSIST, check_bucket_levels_cb, bev);
204 		bufferevent_set_rate_limit(bev, conn_bucket_cfg);
205 
206 		assert(bufferevent_get_token_bucket_cfg(bev) != NULL);
207 		event_add(check_event, ms100_common);
208 	}
209 	if (ratelim_group)
210 		bufferevent_add_to_rate_limit_group(bev, ratelim_group);
211 	++n_echo_conns_open;
212 	bufferevent_enable(bev, EV_READ|EV_WRITE);
213 }
214 
215 /* Called periodically to check up on how full the buckets are */
216 static void
217 check_bucket_levels_cb(evutil_socket_t fd, short events, void *arg)
218 {
219 	struct bufferevent *bev = arg;
220 
221 	ev_ssize_t r = bufferevent_get_read_limit(bev);
222 	ev_ssize_t w = bufferevent_get_write_limit(bev);
223 	ev_ssize_t rm = bufferevent_get_max_to_read(bev);
224 	ev_ssize_t wm = bufferevent_get_max_to_write(bev);
225 	/* XXXX check that no value is above the cofigured burst
226 	 * limit */
227 	total_rbucket_level += r;
228 	total_wbucket_level += w;
229 	total_max_to_read += rm;
230 	total_max_to_write += wm;
231 #define B(x) \
232 	if ((x) > max_bucket_level)		\
233 		max_bucket_level = (x);		\
234 	if ((x) < min_bucket_level)		\
235 		min_bucket_level = (x)
236 	B(r);
237 	B(w);
238 #undef B
239 
240 	total_n_bev_checks++;
241 	if (total_n_bev_checks >= .8 * ((double)cfg_duration / cfg_tick_msec) * cfg_n_connections) {
242 		event_free(event_base_get_running_event(bufferevent_get_base(bev)));
243 	}
244 }
245 
246 static void
247 check_group_bucket_levels_cb(evutil_socket_t fd, short events, void *arg)
248 {
249 	if (ratelim_group) {
250 		ev_ssize_t r = bufferevent_rate_limit_group_get_read_limit(ratelim_group);
251 		ev_ssize_t w = bufferevent_rate_limit_group_get_write_limit(ratelim_group);
252 		total_group_rbucket_level += r;
253 		total_group_wbucket_level += w;
254 	}
255 	++total_n_group_bev_checks;
256 }
257 
258 static void
259 group_drain_cb(evutil_socket_t fd, short events, void *arg)
260 {
261 	bufferevent_rate_limit_group_decrement_read(ratelim_group, cfg_group_drain);
262 	bufferevent_rate_limit_group_decrement_write(ratelim_group, cfg_group_drain);
263 }
264 
265 static void
266 timer_bias_cb(evutil_socket_t fd, short events, void *arg)
267 {
268 	struct event *event = arg;
269 	struct timeval end;
270 	struct timeval diff;
271 
272 	/** XXX: use rdtsc? (portability issues?) */
273 	evutil_gettimeofday(&end, NULL);
274 	evutil_timersub(&end, &timer_bias_start, &diff);
275 	timer_bias_spend += diff.tv_sec + diff.tv_usec * 1e6;
276 	timer_bias_start = end;
277 
278 	if (++timer_bias_events == 100)
279 		event_del(event);
280 }
281 static double
282 timer_bias_calculate(void)
283 {
284 	struct event_config *cfg = NULL;
285 	struct event_base *base = NULL;
286 	struct event *timer = NULL;
287 	struct timeval tv = { 0, 1 };
288 	int done = 0;
289 
290 	cfg = event_config_new();
291 	if (!cfg)
292 		goto err;
293 	if (event_config_set_flag(cfg, EVENT_BASE_FLAG_PRECISE_TIMER))
294 		goto err;
295 	base = event_base_new_with_config(cfg);
296 	if (!base)
297 		goto err;
298 
299 	timer = event_new(base, -1, EV_PERSIST, timer_bias_cb, event_self_cbarg());
300 	if (!timer || event_add(timer, &tv)) {
301 		goto err;
302 	}
303 
304 	evutil_gettimeofday(&timer_bias_start, NULL);
305 	event_base_dispatch(base);
306 	done = 1;
307 
308 err:
309 	if (cfg)
310 		event_config_free(cfg);
311 	if (timer)
312 		event_free(timer);
313 	if (base)
314 		event_base_free(base);
315 
316 	if (done)
317 		return MIN(timer_bias_spend / 1e6 / timer_bias_events / TIMER_MAX_COST_USEC, 5);
318 
319 	fprintf(stderr, "Couldn't create event for CPU cycle counter bias\n");
320 	return -1;
321 }
322 
323 static int
324 test_ratelimiting(void)
325 {
326 	struct event_base *base;
327 	struct sockaddr_in sin;
328 	struct evconnlistener *listener;
329 
330 	struct sockaddr_storage ss;
331 	ev_socklen_t slen;
332 
333 	int i;
334 
335 	struct timeval tv;
336 
337 	ev_uint64_t total_received;
338 	double total_sq_persec, total_persec;
339 	double variance;
340 	double expected_total_persec = -1.0, expected_avg_persec = -1.0;
341 	int ok = 1;
342 	struct event_config *base_cfg;
343 	struct event *periodic_level_check;
344 	struct event *group_drain_event=NULL;
345 	double timer_bias;
346 
347 	memset(&sin, 0, sizeof(sin));
348 	sin.sin_family = AF_INET;
349 	sin.sin_addr.s_addr = htonl(0x7f000001); /* 127.0.0.1 */
350 	sin.sin_port = 0; /* unspecified port */
351 
352 	if (0)
353 		event_enable_debug_mode();
354 
355 	timer_bias = timer_bias_calculate();
356 	if (timer_bias > 1) {
357 		fprintf(stderr, "CPU is slow, timers bias is %f\n", timer_bias);
358 		cfg_connlimit_tolerance  *= timer_bias;
359 		cfg_grouplimit_tolerance *= timer_bias;
360 		cfg_stddev_tolerance     *= timer_bias;
361 	} else {
362 		printf("CPU is fast enough, timers bias is %f\n", timer_bias);
363 	}
364 
365 	base_cfg = event_config_new();
366 
367 #ifdef _WIN32
368 	if (cfg_enable_iocp) {
369 #ifdef EVTHREAD_USE_WINDOWS_THREADS_IMPLEMENTED
370 		evthread_use_windows_threads();
371 #endif
372 		event_config_set_flag(base_cfg, EVENT_BASE_FLAG_STARTUP_IOCP);
373 	}
374 #endif
375 
376 	base = event_base_new_with_config(base_cfg);
377 	event_config_free(base_cfg);
378 	if (! base) {
379 		fprintf(stderr, "Couldn't create event_base");
380 		return 1;
381 	}
382 
383 	listener = evconnlistener_new_bind(base, echo_listenercb, base,
384 	    LEV_OPT_CLOSE_ON_FREE|LEV_OPT_REUSEABLE, -1,
385 	    (struct sockaddr *)&sin, sizeof(sin));
386 	if (! listener) {
387 		fprintf(stderr, "Couldn't create listener");
388 		return 1;
389 	}
390 
391 	slen = sizeof(ss);
392 	if (getsockname(evconnlistener_get_fd(listener), (struct sockaddr *)&ss,
393 		&slen) < 0) {
394 		perror("getsockname");
395 		return 1;
396 	}
397 
398 	if (cfg_connlimit > 0) {
399 		conn_bucket_cfg = ev_token_bucket_cfg_new(
400 			cfg_connlimit, cfg_connlimit * 4,
401 			cfg_connlimit, cfg_connlimit * 4,
402 			&cfg_tick);
403 		assert(conn_bucket_cfg);
404 	}
405 
406 	if (cfg_grouplimit > 0) {
407 		group_bucket_cfg = ev_token_bucket_cfg_new(
408 			cfg_grouplimit, cfg_grouplimit * 4,
409 			cfg_grouplimit, cfg_grouplimit * 4,
410 			&cfg_tick);
411 		group = ratelim_group = bufferevent_rate_limit_group_new(
412 			base, group_bucket_cfg);
413 		expected_total_persec = cfg_grouplimit - (cfg_group_drain / seconds_per_tick);
414 		expected_avg_persec = cfg_grouplimit / cfg_n_connections;
415 		if (cfg_connlimit > 0 && expected_avg_persec > cfg_connlimit)
416 			expected_avg_persec = cfg_connlimit;
417 		if (cfg_min_share >= 0)
418 			bufferevent_rate_limit_group_set_min_share(
419 				ratelim_group, cfg_min_share);
420 	}
421 
422 	if (expected_avg_persec < 0 && cfg_connlimit > 0)
423 		expected_avg_persec = cfg_connlimit;
424 
425 	if (expected_avg_persec > 0)
426 		expected_avg_persec /= seconds_per_tick;
427 	if (expected_total_persec > 0)
428 		expected_total_persec /= seconds_per_tick;
429 
430 	bevs = calloc(cfg_n_connections, sizeof(struct bufferevent *));
431 	states = calloc(cfg_n_connections, sizeof(struct client_state));
432 
433 	for (i = 0; i < cfg_n_connections; ++i) {
434 		bevs[i] = bufferevent_socket_new(base, -1,
435 		    BEV_OPT_CLOSE_ON_FREE|BEV_OPT_THREADSAFE);
436 		assert(bevs[i]);
437 		bufferevent_setcb(bevs[i], discard_readcb, loud_writecb,
438 		    write_on_connectedcb, &states[i]);
439 		bufferevent_enable(bevs[i], EV_READ|EV_WRITE);
440 		bufferevent_socket_connect(bevs[i], (struct sockaddr *)&ss,
441 		    slen);
442 	}
443 
444 	tv.tv_sec = cfg_duration - 1;
445 	tv.tv_usec = 995000;
446 
447 	event_base_loopexit(base, &tv);
448 
449 	tv.tv_sec = 0;
450 	tv.tv_usec = 100*1000;
451 	ms100_common = event_base_init_common_timeout(base, &tv);
452 
453 	periodic_level_check = event_new(base, -1, EV_PERSIST, check_group_bucket_levels_cb, NULL);
454 	event_add(periodic_level_check, ms100_common);
455 
456 	if (cfg_group_drain && ratelim_group) {
457 		group_drain_event = event_new(base, -1, EV_PERSIST, group_drain_cb, NULL);
458 		event_add(group_drain_event, &cfg_tick);
459 	}
460 
461 	event_base_dispatch(base);
462 
463 	ratelim_group = NULL; /* So no more responders get added */
464 	event_free(periodic_level_check);
465 	if (group_drain_event)
466 		event_free(group_drain_event);
467 
468 	for (i = 0; i < cfg_n_connections; ++i) {
469 		bufferevent_free(bevs[i]);
470 	}
471 	evconnlistener_free(listener);
472 
473 	/* Make sure no new echo_conns get added to the group. */
474 	ratelim_group = NULL;
475 
476 	/* This should get _everybody_ freed */
477 	while (n_echo_conns_open) {
478 		printf("waiting for %d conns\n", n_echo_conns_open);
479 		tv.tv_sec = 0;
480 		tv.tv_usec = 300000;
481 		event_base_loopexit(base, &tv);
482 		event_base_dispatch(base);
483 	}
484 
485 	if (group)
486 		bufferevent_rate_limit_group_free(group);
487 
488 	if (total_n_bev_checks) {
489 		printf("Average read bucket level: %f\n",
490 		    (double)total_rbucket_level/total_n_bev_checks);
491 		printf("Average write bucket level: %f\n",
492 		    (double)total_wbucket_level/total_n_bev_checks);
493 		printf("Highest read bucket level: %f\n",
494 		    (double)max_bucket_level);
495 		printf("Highest write bucket level: %f\n",
496 		    (double)min_bucket_level);
497 		printf("Average max-to-read: %f\n",
498 		    ((double)total_max_to_read)/total_n_bev_checks);
499 		printf("Average max-to-write: %f\n",
500 		    ((double)total_max_to_write)/total_n_bev_checks);
501 	}
502 	if (total_n_group_bev_checks) {
503 		printf("Average group read bucket level: %f\n",
504 		    ((double)total_group_rbucket_level)/total_n_group_bev_checks);
505 		printf("Average group write bucket level: %f\n",
506 		    ((double)total_group_wbucket_level)/total_n_group_bev_checks);
507 	}
508 
509 	total_received = 0;
510 	total_persec = 0.0;
511 	total_sq_persec = 0.0;
512 	for (i=0; i < cfg_n_connections; ++i) {
513 		double persec = states[i].received;
514 		persec /= cfg_duration;
515 		total_received += states[i].received;
516 		total_persec += persec;
517 		total_sq_persec += persec*persec;
518 		printf("%d: %f per second\n", i+1, persec);
519 	}
520 	printf("   total: %f per second\n",
521 	    ((double)total_received)/cfg_duration);
522 	if (expected_total_persec > 0) {
523 		double diff = expected_total_persec -
524 		    ((double)total_received/cfg_duration);
525 		printf("  [Off by %lf]\n", diff);
526 		if (cfg_grouplimit_tolerance > 0 &&
527 		    fabs(diff) > cfg_grouplimit_tolerance) {
528 			fprintf(stderr, "Group bandwidth out of bounds\n");
529 			ok = 0;
530 		}
531 	}
532 
533 	printf(" average: %f per second\n",
534 	    (((double)total_received)/cfg_duration)/cfg_n_connections);
535 	if (expected_avg_persec > 0) {
536 		double diff = expected_avg_persec - (((double)total_received)/cfg_duration)/cfg_n_connections;
537 		printf("  [Off by %lf]\n", diff);
538 		if (cfg_connlimit_tolerance > 0 &&
539 		    fabs(diff) > cfg_connlimit_tolerance) {
540 			fprintf(stderr, "Connection bandwidth out of bounds\n");
541 			ok = 0;
542 		}
543 	}
544 
545 	variance = total_sq_persec/cfg_n_connections - total_persec*total_persec/(cfg_n_connections*cfg_n_connections);
546 
547 	printf("  stddev: %f per second\n", sqrt(variance));
548 	if (cfg_stddev_tolerance > 0 &&
549 	    sqrt(variance) > cfg_stddev_tolerance) {
550 		fprintf(stderr, "Connection variance out of bounds\n");
551 		ok = 0;
552 	}
553 
554 	event_base_free(base);
555 	free(bevs);
556 	free(states);
557 
558 	return ok ? 0 : 1;
559 }
560 
561 static struct option {
562 	const char *name; int *ptr; int min; int isbool;
563 } options[] = {
564 	{ "-v", &cfg_verbose, 0, 1 },
565 	{ "-h", &cfg_help, 0, 1 },
566 	{ "-n", &cfg_n_connections, 1, 0 },
567 	{ "-d", &cfg_duration, 1, 0 },
568 	{ "-c", &cfg_connlimit, 0, 0 },
569 	{ "-g", &cfg_grouplimit, 0, 0 },
570 	{ "-G", &cfg_group_drain, -100000, 0 },
571 	{ "-t", &cfg_tick_msec, 10, 0 },
572 	{ "--min-share", &cfg_min_share, 0, 0 },
573 	{ "--check-connlimit", &cfg_connlimit_tolerance, 0, 0 },
574 	{ "--check-grouplimit", &cfg_grouplimit_tolerance, 0, 0 },
575 	{ "--check-stddev", &cfg_stddev_tolerance, 0, 0 },
576 #ifdef _WIN32
577 	{ "--iocp", &cfg_enable_iocp, 0, 1 },
578 #endif
579 	{ NULL, NULL, -1, 0 },
580 };
581 
582 static int
583 handle_option(int argc, char **argv, int *i, const struct option *opt)
584 {
585 	long val;
586 	char *endptr = NULL;
587 	if (opt->isbool) {
588 		*opt->ptr = 1;
589 		return 0;
590 	}
591 	if (*i + 1 == argc) {
592 		fprintf(stderr, "Too few arguments to '%s'\n",argv[*i]);
593 		return -1;
594 	}
595 	val = strtol(argv[*i+1], &endptr, 10);
596 	if (*argv[*i+1] == '\0' || !endptr || *endptr != '\0') {
597 		fprintf(stderr, "Couldn't parse numeric value '%s'\n",
598 		    argv[*i+1]);
599 		return -1;
600 	}
601 	if (val < opt->min || val > 0x7fffffff) {
602 		fprintf(stderr, "Value '%s' is out-of-range'\n",
603 		    argv[*i+1]);
604 		return -1;
605 	}
606 	*opt->ptr = (int)val;
607 	++*i;
608 	return 0;
609 }
610 
611 static void
612 usage(void)
613 {
614 	fprintf(stderr,
615 "test-ratelim [-v] [-n INT] [-d INT] [-c INT] [-g INT] [-t INT]\n\n"
616 "Pushes bytes through a number of possibly rate-limited connections, and\n"
617 "displays average throughput.\n\n"
618 "  -n INT: Number of connections to open (default: 30)\n"
619 "  -d INT: Duration of the test in seconds (default: 5 sec)\n");
620 	fprintf(stderr,
621 "  -c INT: Connection-rate limit applied to each connection in bytes per second\n"
622 "	   (default: None.)\n"
623 "  -g INT: Group-rate limit applied to sum of all usage in bytes per second\n"
624 "	   (default: None.)\n"
625 "  -G INT: drain INT bytes from the group limit every tick. (default: 0)\n"
626 "  -t INT: Granularity of timing, in milliseconds (default: 1000 msec)\n");
627 }
628 
629 int
630 main(int argc, char **argv)
631 {
632 	int i,j;
633 	double ratio;
634 
635 #ifdef _WIN32
636 	WORD wVersionRequested = MAKEWORD(2,2);
637 	WSADATA wsaData;
638 
639 	(void) WSAStartup(wVersionRequested, &wsaData);
640 #endif
641 
642 	evutil_weakrand_seed_(&weakrand_state, 0);
643 
644 #ifndef _WIN32
645 	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
646 		return 1;
647 #endif
648 	for (i = 1; i < argc; ++i) {
649 		for (j = 0; options[j].name; ++j) {
650 			if (!strcmp(argv[i],options[j].name)) {
651 				if (handle_option(argc,argv,&i,&options[j])<0)
652 					return 1;
653 				goto again;
654 			}
655 		}
656 		fprintf(stderr, "Unknown option '%s'\n", argv[i]);
657 		usage();
658 		return 1;
659 	again:
660 		;
661 	}
662 	if (cfg_help) {
663 		usage();
664 		return 0;
665 	}
666 
667 	cfg_tick.tv_sec = cfg_tick_msec / 1000;
668 	cfg_tick.tv_usec = (cfg_tick_msec % 1000)*1000;
669 
670 	seconds_per_tick = ratio = cfg_tick_msec / 1000.0;
671 
672 	cfg_connlimit *= ratio;
673 	cfg_grouplimit *= ratio;
674 
675 	{
676 		struct timeval tv;
677 		evutil_gettimeofday(&tv, NULL);
678 #ifdef _WIN32
679 		srand(tv.tv_usec);
680 #else
681 		srandom(tv.tv_usec);
682 #endif
683 	}
684 
685 #ifndef EVENT__DISABLE_THREAD_SUPPORT
686 	evthread_enable_lock_debugging();
687 #endif
688 
689 	return test_ratelimiting();
690 }
691