xref: /freebsd/contrib/libevent/test/test-ratelim.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*
2  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 #include "../util-internal.h"
27 
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <assert.h>
32 #include <math.h>
33 
34 #ifdef _WIN32
35 #include <winsock2.h>
36 #include <ws2tcpip.h>
37 #else
38 #include <sys/socket.h>
39 #include <netinet/in.h>
40 # ifdef _XOPEN_SOURCE_EXTENDED
41 #  include <arpa/inet.h>
42 # endif
43 #endif
44 #include <signal.h>
45 
46 #include "event2/bufferevent.h"
47 #include "event2/buffer.h"
48 #include "event2/event.h"
49 #include "event2/util.h"
50 #include "event2/listener.h"
51 #include "event2/thread.h"
52 
53 #ifndef MIN
54 #define MIN(a,b) (((a)<(b))?(a):(b))
55 #endif
56 
57 static struct evutil_weakrand_state weakrand_state;
58 
59 static int cfg_verbose = 0;
60 static int cfg_help = 0;
61 
62 static int cfg_n_connections = 30;
63 static int cfg_duration = 5;
64 static int cfg_connlimit = 0;
65 static int cfg_grouplimit = 0;
66 static int cfg_tick_msec = 1000;
67 static int cfg_min_share = -1;
68 static int cfg_group_drain = 0;
69 
70 static int cfg_connlimit_tolerance = -1;
71 static int cfg_grouplimit_tolerance = -1;
72 static int cfg_stddev_tolerance = -1;
73 
74 #ifdef _WIN32
75 static int cfg_enable_iocp = 0;
76 #endif
77 
78 static struct timeval cfg_tick = { 0, 500*1000 };
79 
80 static struct ev_token_bucket_cfg *conn_bucket_cfg = NULL;
81 static struct ev_token_bucket_cfg *group_bucket_cfg = NULL;
82 struct bufferevent_rate_limit_group *ratelim_group = NULL;
83 static double seconds_per_tick = 0.0;
84 
85 struct client_state {
86 	size_t queued;
87 	ev_uint64_t received;
88 
89 };
90 static const struct timeval *ms100_common=NULL;
91 
92 /* Timers bias for slow CPUs, affects:
93  * - cfg_connlimit_tolerance  (--check-connlimit)
94  * - cfg_grouplimit_tolerance (--check-grouplimit)
95  * - cfg_stddev_tolerance     (--check-stddev)
96  */
97 static int timer_bias_events;
98 static struct timeval timer_bias_start;
99 double timer_bias_spend;
100 /* Real cost is less (approximately ~5 usec),
101  * this macros adjusted to make the bias less */
102 #define TIMER_MAX_COST_USEC 10
103 
104 /* info from check_bucket_levels_cb */
105 static int total_n_bev_checks = 0;
106 static ev_int64_t total_rbucket_level=0;
107 static ev_int64_t total_wbucket_level=0;
108 static ev_int64_t total_max_to_read=0;
109 static ev_int64_t total_max_to_write=0;
110 static ev_int64_t max_bucket_level=EV_INT64_MIN;
111 static ev_int64_t min_bucket_level=EV_INT64_MAX;
112 
113 /* from check_group_bucket_levels_cb */
114 static int total_n_group_bev_checks = 0;
115 static ev_int64_t total_group_rbucket_level = 0;
116 static ev_int64_t total_group_wbucket_level = 0;
117 
118 static int n_echo_conns_open = 0;
119 
120 /* Info on the open connections */
121 struct bufferevent **bevs;
122 struct client_state *states;
123 struct bufferevent_rate_limit_group *group = NULL;
124 
125 static void check_bucket_levels_cb(evutil_socket_t fd, short events, void *arg);
126 
127 static void
128 loud_writecb(struct bufferevent *bev, void *ctx)
129 {
130 	struct client_state *cs = ctx;
131 	struct evbuffer *output = bufferevent_get_output(bev);
132 	char buf[1024];
133 	int r = evutil_weakrand_(&weakrand_state);
134 	memset(buf, r, sizeof(buf));
135 	while (evbuffer_get_length(output) < 8192) {
136 		evbuffer_add(output, buf, sizeof(buf));
137 		cs->queued += sizeof(buf);
138 	}
139 }
140 
141 static void
142 discard_readcb(struct bufferevent *bev, void *ctx)
143 {
144 	struct client_state *cs = ctx;
145 	struct evbuffer *input = bufferevent_get_input(bev);
146 	size_t len = evbuffer_get_length(input);
147 	evbuffer_drain(input, len);
148 	cs->received += len;
149 }
150 
151 static void
152 write_on_connectedcb(struct bufferevent *bev, short what, void *ctx)
153 {
154 	if (what & BEV_EVENT_CONNECTED) {
155 		loud_writecb(bev, ctx);
156 		/* XXXX this shouldn't be needed. */
157 		bufferevent_enable(bev, EV_READ|EV_WRITE);
158 	}
159 }
160 
161 static void
162 echo_readcb(struct bufferevent *bev, void *ctx)
163 {
164 	struct evbuffer *input = bufferevent_get_input(bev);
165 	struct evbuffer *output = bufferevent_get_output(bev);
166 
167 	evbuffer_add_buffer(output, input);
168 	if (evbuffer_get_length(output) > 1024000)
169 		bufferevent_disable(bev, EV_READ);
170 }
171 
172 static void
173 echo_writecb(struct bufferevent *bev, void *ctx)
174 {
175 	struct evbuffer *output = bufferevent_get_output(bev);
176 	if (evbuffer_get_length(output) < 512000)
177 		bufferevent_enable(bev, EV_READ);
178 }
179 
180 static void
181 echo_eventcb(struct bufferevent *bev, short what, void *ctx)
182 {
183 	if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
184 		--n_echo_conns_open;
185 		bufferevent_free(bev);
186 	}
187 }
188 
189 static void
190 echo_listenercb(struct evconnlistener *listener, evutil_socket_t newsock,
191     struct sockaddr *sourceaddr, int socklen, void *ctx)
192 {
193 	struct event_base *base = ctx;
194 	int flags = BEV_OPT_CLOSE_ON_FREE|BEV_OPT_THREADSAFE;
195 	struct bufferevent *bev;
196 
197 	bev = bufferevent_socket_new(base, newsock, flags);
198 	bufferevent_setcb(bev, echo_readcb, echo_writecb, echo_eventcb, NULL);
199 	if (conn_bucket_cfg) {
200 		struct event *check_event =
201 		    event_new(base, -1, EV_PERSIST, check_bucket_levels_cb, bev);
202 		bufferevent_set_rate_limit(bev, conn_bucket_cfg);
203 
204 		assert(bufferevent_get_token_bucket_cfg(bev) != NULL);
205 		event_add(check_event, ms100_common);
206 	}
207 	if (ratelim_group)
208 		bufferevent_add_to_rate_limit_group(bev, ratelim_group);
209 	++n_echo_conns_open;
210 	bufferevent_enable(bev, EV_READ|EV_WRITE);
211 }
212 
213 /* Called periodically to check up on how full the buckets are */
214 static void
215 check_bucket_levels_cb(evutil_socket_t fd, short events, void *arg)
216 {
217 	struct bufferevent *bev = arg;
218 
219 	ev_ssize_t r = bufferevent_get_read_limit(bev);
220 	ev_ssize_t w = bufferevent_get_write_limit(bev);
221 	ev_ssize_t rm = bufferevent_get_max_to_read(bev);
222 	ev_ssize_t wm = bufferevent_get_max_to_write(bev);
223 	/* XXXX check that no value is above the cofigured burst
224 	 * limit */
225 	total_rbucket_level += r;
226 	total_wbucket_level += w;
227 	total_max_to_read += rm;
228 	total_max_to_write += wm;
229 #define B(x) \
230 	if ((x) > max_bucket_level)		\
231 		max_bucket_level = (x);		\
232 	if ((x) < min_bucket_level)		\
233 		min_bucket_level = (x)
234 	B(r);
235 	B(w);
236 #undef B
237 
238 	total_n_bev_checks++;
239 	if (total_n_bev_checks >= .8 * ((double)cfg_duration / cfg_tick_msec) * cfg_n_connections) {
240 		event_free(event_base_get_running_event(bufferevent_get_base(bev)));
241 	}
242 }
243 
244 static void
245 check_group_bucket_levels_cb(evutil_socket_t fd, short events, void *arg)
246 {
247 	if (ratelim_group) {
248 		ev_ssize_t r = bufferevent_rate_limit_group_get_read_limit(ratelim_group);
249 		ev_ssize_t w = bufferevent_rate_limit_group_get_write_limit(ratelim_group);
250 		total_group_rbucket_level += r;
251 		total_group_wbucket_level += w;
252 	}
253 	++total_n_group_bev_checks;
254 }
255 
256 static void
257 group_drain_cb(evutil_socket_t fd, short events, void *arg)
258 {
259 	bufferevent_rate_limit_group_decrement_read(ratelim_group, cfg_group_drain);
260 	bufferevent_rate_limit_group_decrement_write(ratelim_group, cfg_group_drain);
261 }
262 
263 static void
264 timer_bias_cb(evutil_socket_t fd, short events, void *arg)
265 {
266 	struct event *event = arg;
267 	struct timeval end;
268 	struct timeval diff;
269 
270 	/** XXX: use rdtsc? (portability issues?) */
271 	evutil_gettimeofday(&end, NULL);
272 	evutil_timersub(&end, &timer_bias_start, &diff);
273 	timer_bias_spend += diff.tv_sec + diff.tv_usec * 1e6;
274 	timer_bias_start = end;
275 
276 	if (++timer_bias_events == 100)
277 		event_del(event);
278 }
279 static double
280 timer_bias_calculate(void)
281 {
282 	struct event_config *cfg = NULL;
283 	struct event_base *base = NULL;
284 	struct event *timer = NULL;
285 	struct timeval tv = { 0, 1 };
286 	int done = 0;
287 
288 	cfg = event_config_new();
289 	if (!cfg)
290 		goto err;
291 	if (event_config_set_flag(cfg, EVENT_BASE_FLAG_PRECISE_TIMER))
292 		goto err;
293 	base = event_base_new_with_config(cfg);
294 	if (!base)
295 		goto err;
296 
297 	timer = event_new(base, -1, EV_PERSIST, timer_bias_cb, event_self_cbarg());
298 	if (!timer || event_add(timer, &tv)) {
299 		goto err;
300 	}
301 
302 	evutil_gettimeofday(&timer_bias_start, NULL);
303 	event_base_dispatch(base);
304 	done = 1;
305 
306 err:
307 	if (cfg)
308 		event_config_free(cfg);
309 	if (timer)
310 		event_free(timer);
311 	if (base)
312 		event_base_free(base);
313 
314 	if (done)
315 		return MIN(timer_bias_spend / 1e6 / timer_bias_events / TIMER_MAX_COST_USEC, 5);
316 
317 	fprintf(stderr, "Couldn't create event for CPU cycle counter bias\n");
318 	return -1;
319 }
320 
321 static int
322 test_ratelimiting(void)
323 {
324 	struct event_base *base;
325 	struct sockaddr_in sin;
326 	struct evconnlistener *listener;
327 
328 	struct sockaddr_storage ss;
329 	ev_socklen_t slen;
330 
331 	int i;
332 
333 	struct timeval tv;
334 
335 	ev_uint64_t total_received;
336 	double total_sq_persec, total_persec;
337 	double variance;
338 	double expected_total_persec = -1.0, expected_avg_persec = -1.0;
339 	int ok = 1;
340 	struct event_config *base_cfg;
341 	struct event *periodic_level_check;
342 	struct event *group_drain_event=NULL;
343 	double timer_bias;
344 
345 	memset(&sin, 0, sizeof(sin));
346 	sin.sin_family = AF_INET;
347 	sin.sin_addr.s_addr = htonl(0x7f000001); /* 127.0.0.1 */
348 	sin.sin_port = 0; /* unspecified port */
349 
350 	if (0)
351 		event_enable_debug_mode();
352 
353 	timer_bias = timer_bias_calculate();
354 	if (timer_bias > 1) {
355 		fprintf(stderr, "CPU is slow, timers bias is %f\n", timer_bias);
356 		cfg_connlimit_tolerance  *= timer_bias;
357 		cfg_grouplimit_tolerance *= timer_bias;
358 		cfg_stddev_tolerance     *= timer_bias;
359 	} else {
360 		printf("CPU is fast enough, timers bias is %f\n", timer_bias);
361 	}
362 
363 	base_cfg = event_config_new();
364 
365 #ifdef _WIN32
366 	if (cfg_enable_iocp) {
367 #ifdef EVTHREAD_USE_WINDOWS_THREADS_IMPLEMENTED
368 		evthread_use_windows_threads();
369 #endif
370 		event_config_set_flag(base_cfg, EVENT_BASE_FLAG_STARTUP_IOCP);
371 	}
372 #endif
373 
374 	base = event_base_new_with_config(base_cfg);
375 	event_config_free(base_cfg);
376 	if (! base) {
377 		fprintf(stderr, "Couldn't create event_base");
378 		return 1;
379 	}
380 
381 	listener = evconnlistener_new_bind(base, echo_listenercb, base,
382 	    LEV_OPT_CLOSE_ON_FREE|LEV_OPT_REUSEABLE, -1,
383 	    (struct sockaddr *)&sin, sizeof(sin));
384 	if (! listener) {
385 		fprintf(stderr, "Couldn't create listener");
386 		return 1;
387 	}
388 
389 	slen = sizeof(ss);
390 	if (getsockname(evconnlistener_get_fd(listener), (struct sockaddr *)&ss,
391 		&slen) < 0) {
392 		perror("getsockname");
393 		return 1;
394 	}
395 
396 	if (cfg_connlimit > 0) {
397 		conn_bucket_cfg = ev_token_bucket_cfg_new(
398 			cfg_connlimit, cfg_connlimit * 4,
399 			cfg_connlimit, cfg_connlimit * 4,
400 			&cfg_tick);
401 		assert(conn_bucket_cfg);
402 	}
403 
404 	if (cfg_grouplimit > 0) {
405 		group_bucket_cfg = ev_token_bucket_cfg_new(
406 			cfg_grouplimit, cfg_grouplimit * 4,
407 			cfg_grouplimit, cfg_grouplimit * 4,
408 			&cfg_tick);
409 		group = ratelim_group = bufferevent_rate_limit_group_new(
410 			base, group_bucket_cfg);
411 		expected_total_persec = cfg_grouplimit - (cfg_group_drain / seconds_per_tick);
412 		expected_avg_persec = cfg_grouplimit / cfg_n_connections;
413 		if (cfg_connlimit > 0 && expected_avg_persec > cfg_connlimit)
414 			expected_avg_persec = cfg_connlimit;
415 		if (cfg_min_share >= 0)
416 			bufferevent_rate_limit_group_set_min_share(
417 				ratelim_group, cfg_min_share);
418 	}
419 
420 	if (expected_avg_persec < 0 && cfg_connlimit > 0)
421 		expected_avg_persec = cfg_connlimit;
422 
423 	if (expected_avg_persec > 0)
424 		expected_avg_persec /= seconds_per_tick;
425 	if (expected_total_persec > 0)
426 		expected_total_persec /= seconds_per_tick;
427 
428 	bevs = calloc(cfg_n_connections, sizeof(struct bufferevent *));
429 	states = calloc(cfg_n_connections, sizeof(struct client_state));
430 
431 	for (i = 0; i < cfg_n_connections; ++i) {
432 		bevs[i] = bufferevent_socket_new(base, -1,
433 		    BEV_OPT_CLOSE_ON_FREE|BEV_OPT_THREADSAFE);
434 		assert(bevs[i]);
435 		bufferevent_setcb(bevs[i], discard_readcb, loud_writecb,
436 		    write_on_connectedcb, &states[i]);
437 		bufferevent_enable(bevs[i], EV_READ|EV_WRITE);
438 		bufferevent_socket_connect(bevs[i], (struct sockaddr *)&ss,
439 		    slen);
440 	}
441 
442 	tv.tv_sec = cfg_duration - 1;
443 	tv.tv_usec = 995000;
444 
445 	event_base_loopexit(base, &tv);
446 
447 	tv.tv_sec = 0;
448 	tv.tv_usec = 100*1000;
449 	ms100_common = event_base_init_common_timeout(base, &tv);
450 
451 	periodic_level_check = event_new(base, -1, EV_PERSIST, check_group_bucket_levels_cb, NULL);
452 	event_add(periodic_level_check, ms100_common);
453 
454 	if (cfg_group_drain && ratelim_group) {
455 		group_drain_event = event_new(base, -1, EV_PERSIST, group_drain_cb, NULL);
456 		event_add(group_drain_event, &cfg_tick);
457 	}
458 
459 	event_base_dispatch(base);
460 
461 	ratelim_group = NULL; /* So no more responders get added */
462 	event_free(periodic_level_check);
463 	if (group_drain_event)
464 		event_free(group_drain_event);
465 
466 	for (i = 0; i < cfg_n_connections; ++i) {
467 		bufferevent_free(bevs[i]);
468 	}
469 	evconnlistener_free(listener);
470 
471 	/* Make sure no new echo_conns get added to the group. */
472 	ratelim_group = NULL;
473 
474 	/* This should get _everybody_ freed */
475 	while (n_echo_conns_open) {
476 		printf("waiting for %d conns\n", n_echo_conns_open);
477 		tv.tv_sec = 0;
478 		tv.tv_usec = 300000;
479 		event_base_loopexit(base, &tv);
480 		event_base_dispatch(base);
481 	}
482 
483 	if (group)
484 		bufferevent_rate_limit_group_free(group);
485 
486 	if (total_n_bev_checks) {
487 		printf("Average read bucket level: %f\n",
488 		    (double)total_rbucket_level/total_n_bev_checks);
489 		printf("Average write bucket level: %f\n",
490 		    (double)total_wbucket_level/total_n_bev_checks);
491 		printf("Highest read bucket level: %f\n",
492 		    (double)max_bucket_level);
493 		printf("Highest write bucket level: %f\n",
494 		    (double)min_bucket_level);
495 		printf("Average max-to-read: %f\n",
496 		    ((double)total_max_to_read)/total_n_bev_checks);
497 		printf("Average max-to-write: %f\n",
498 		    ((double)total_max_to_write)/total_n_bev_checks);
499 	}
500 	if (total_n_group_bev_checks) {
501 		printf("Average group read bucket level: %f\n",
502 		    ((double)total_group_rbucket_level)/total_n_group_bev_checks);
503 		printf("Average group write bucket level: %f\n",
504 		    ((double)total_group_wbucket_level)/total_n_group_bev_checks);
505 	}
506 
507 	total_received = 0;
508 	total_persec = 0.0;
509 	total_sq_persec = 0.0;
510 	for (i=0; i < cfg_n_connections; ++i) {
511 		double persec = states[i].received;
512 		persec /= cfg_duration;
513 		total_received += states[i].received;
514 		total_persec += persec;
515 		total_sq_persec += persec*persec;
516 		printf("%d: %f per second\n", i+1, persec);
517 	}
518 	printf("   total: %f per second\n",
519 	    ((double)total_received)/cfg_duration);
520 	if (expected_total_persec > 0) {
521 		double diff = expected_total_persec -
522 		    ((double)total_received/cfg_duration);
523 		printf("  [Off by %lf]\n", diff);
524 		if (cfg_grouplimit_tolerance > 0 &&
525 		    fabs(diff) > cfg_grouplimit_tolerance) {
526 			fprintf(stderr, "Group bandwidth out of bounds\n");
527 			ok = 0;
528 		}
529 	}
530 
531 	printf(" average: %f per second\n",
532 	    (((double)total_received)/cfg_duration)/cfg_n_connections);
533 	if (expected_avg_persec > 0) {
534 		double diff = expected_avg_persec - (((double)total_received)/cfg_duration)/cfg_n_connections;
535 		printf("  [Off by %lf]\n", diff);
536 		if (cfg_connlimit_tolerance > 0 &&
537 		    fabs(diff) > cfg_connlimit_tolerance) {
538 			fprintf(stderr, "Connection bandwidth out of bounds\n");
539 			ok = 0;
540 		}
541 	}
542 
543 	variance = total_sq_persec/cfg_n_connections - total_persec*total_persec/(cfg_n_connections*cfg_n_connections);
544 
545 	printf("  stddev: %f per second\n", sqrt(variance));
546 	if (cfg_stddev_tolerance > 0 &&
547 	    sqrt(variance) > cfg_stddev_tolerance) {
548 		fprintf(stderr, "Connection variance out of bounds\n");
549 		ok = 0;
550 	}
551 
552 	event_base_free(base);
553 	free(bevs);
554 	free(states);
555 
556 	return ok ? 0 : 1;
557 }
558 
559 static struct option {
560 	const char *name; int *ptr; int min; int isbool;
561 } options[] = {
562 	{ "-v", &cfg_verbose, 0, 1 },
563 	{ "-h", &cfg_help, 0, 1 },
564 	{ "-n", &cfg_n_connections, 1, 0 },
565 	{ "-d", &cfg_duration, 1, 0 },
566 	{ "-c", &cfg_connlimit, 0, 0 },
567 	{ "-g", &cfg_grouplimit, 0, 0 },
568 	{ "-G", &cfg_group_drain, -100000, 0 },
569 	{ "-t", &cfg_tick_msec, 10, 0 },
570 	{ "--min-share", &cfg_min_share, 0, 0 },
571 	{ "--check-connlimit", &cfg_connlimit_tolerance, 0, 0 },
572 	{ "--check-grouplimit", &cfg_grouplimit_tolerance, 0, 0 },
573 	{ "--check-stddev", &cfg_stddev_tolerance, 0, 0 },
574 #ifdef _WIN32
575 	{ "--iocp", &cfg_enable_iocp, 0, 1 },
576 #endif
577 	{ NULL, NULL, -1, 0 },
578 };
579 
580 static int
581 handle_option(int argc, char **argv, int *i, const struct option *opt)
582 {
583 	long val;
584 	char *endptr = NULL;
585 	if (opt->isbool) {
586 		*opt->ptr = 1;
587 		return 0;
588 	}
589 	if (*i + 1 == argc) {
590 		fprintf(stderr, "Too few arguments to '%s'\n",argv[*i]);
591 		return -1;
592 	}
593 	val = strtol(argv[*i+1], &endptr, 10);
594 	if (*argv[*i+1] == '\0' || !endptr || *endptr != '\0') {
595 		fprintf(stderr, "Couldn't parse numeric value '%s'\n",
596 		    argv[*i+1]);
597 		return -1;
598 	}
599 	if (val < opt->min || val > 0x7fffffff) {
600 		fprintf(stderr, "Value '%s' is out-of-range'\n",
601 		    argv[*i+1]);
602 		return -1;
603 	}
604 	*opt->ptr = (int)val;
605 	++*i;
606 	return 0;
607 }
608 
609 static void
610 usage(void)
611 {
612 	fprintf(stderr,
613 "test-ratelim [-v] [-n INT] [-d INT] [-c INT] [-g INT] [-t INT]\n\n"
614 "Pushes bytes through a number of possibly rate-limited connections, and\n"
615 "displays average throughput.\n\n"
616 "  -n INT: Number of connections to open (default: 30)\n"
617 "  -d INT: Duration of the test in seconds (default: 5 sec)\n");
618 	fprintf(stderr,
619 "  -c INT: Connection-rate limit applied to each connection in bytes per second\n"
620 "	   (default: None.)\n"
621 "  -g INT: Group-rate limit applied to sum of all usage in bytes per second\n"
622 "	   (default: None.)\n"
623 "  -G INT: drain INT bytes from the group limit every tick. (default: 0)\n"
624 "  -t INT: Granularity of timing, in milliseconds (default: 1000 msec)\n");
625 }
626 
627 int
628 main(int argc, char **argv)
629 {
630 	int i,j;
631 	double ratio;
632 
633 #ifdef _WIN32
634 	WORD wVersionRequested = MAKEWORD(2,2);
635 	WSADATA wsaData;
636 
637 	(void) WSAStartup(wVersionRequested, &wsaData);
638 #endif
639 
640 	evutil_weakrand_seed_(&weakrand_state, 0);
641 
642 #ifndef _WIN32
643 	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
644 		return 1;
645 #endif
646 	for (i = 1; i < argc; ++i) {
647 		for (j = 0; options[j].name; ++j) {
648 			if (!strcmp(argv[i],options[j].name)) {
649 				if (handle_option(argc,argv,&i,&options[j])<0)
650 					return 1;
651 				goto again;
652 			}
653 		}
654 		fprintf(stderr, "Unknown option '%s'\n", argv[i]);
655 		usage();
656 		return 1;
657 	again:
658 		;
659 	}
660 	if (cfg_help) {
661 		usage();
662 		return 0;
663 	}
664 
665 	cfg_tick.tv_sec = cfg_tick_msec / 1000;
666 	cfg_tick.tv_usec = (cfg_tick_msec % 1000)*1000;
667 
668 	seconds_per_tick = ratio = cfg_tick_msec / 1000.0;
669 
670 	cfg_connlimit *= ratio;
671 	cfg_grouplimit *= ratio;
672 
673 	{
674 		struct timeval tv;
675 		evutil_gettimeofday(&tv, NULL);
676 #ifdef _WIN32
677 		srand(tv.tv_usec);
678 #else
679 		srandom(tv.tv_usec);
680 #endif
681 	}
682 
683 #ifndef EVENT__DISABLE_THREAD_SUPPORT
684 	evthread_enable_lock_debugging();
685 #endif
686 
687 	return test_ratelimiting();
688 }
689