1/*
2 * Copyright 2003-2007 Niels Provos <provos@citi.umich.edu>
3 * Copyright 2007-2012 Niels Provos and Nick Mathewson
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 *
28 * Mon 03/10/2003 - Modified by Davide Libenzi <davidel@xmailserver.org>
29 *
30 *     Added chain event propagation to improve the sensitivity of
31 *     the measure respect to the event loop efficency.
32 *
33 *
34 */
35
36#include "event2/event-config.h"
37
38#include <sys/types.h>
39#include <sys/stat.h>
40#ifdef EVENT__HAVE_SYS_TIME_H
41#include <sys/time.h>
42#endif
43#ifdef _WIN32
44#define WIN32_LEAN_AND_MEAN
45#include <windows.h>
46#else
47#include <sys/socket.h>
48#include <signal.h>
49#include <sys/resource.h>
50#endif
51#include <fcntl.h>
52#include <stdlib.h>
53#include <stdio.h>
54#include <string.h>
55#ifdef EVENT__HAVE_UNISTD_H
56#include <unistd.h>
57#endif
58#include <errno.h>
59
60#ifdef _WIN32
61#include <getopt.h>
62#endif
63
64#include <event.h>
65#include <evutil.h>
66
67static int count, writes, fired, failures;
68static evutil_socket_t *pipes;
69static int num_pipes, num_active, num_writes;
70static struct event *events;
71
72
73static void
74read_cb(evutil_socket_t fd, short which, void *arg)
75{
76	ev_intptr_t idx = (ev_intptr_t) arg, widx = idx + 1;
77	unsigned char ch;
78	ev_ssize_t n;
79
80	n = recv(fd, (char*)&ch, sizeof(ch), 0);
81	if (n >= 0)
82		count += n;
83	else
84		failures++;
85	if (writes) {
86		if (widx >= num_pipes)
87			widx -= num_pipes;
88		n = send(pipes[2 * widx + 1], "e", 1, 0);
89		if (n != 1)
90			failures++;
91		writes--;
92		fired++;
93	}
94}
95
96static struct timeval *
97run_once(void)
98{
99	evutil_socket_t *cp, space;
100	long i;
101	static struct timeval ts, te;
102
103	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
104		if (event_initialized(&events[i]))
105			event_del(&events[i]);
106		event_set(&events[i], cp[0], EV_READ | EV_PERSIST, read_cb, (void *)(ev_intptr_t) i);
107		event_add(&events[i], NULL);
108	}
109
110	event_loop(EVLOOP_ONCE | EVLOOP_NONBLOCK);
111
112	fired = 0;
113	space = num_pipes / num_active;
114	space = space * 2;
115	for (i = 0; i < num_active; i++, fired++)
116		(void) send(pipes[i * space + 1], "e", 1, 0);
117
118	count = 0;
119	writes = num_writes;
120	{ int xcount = 0;
121	evutil_gettimeofday(&ts, NULL);
122	do {
123		event_loop(EVLOOP_ONCE | EVLOOP_NONBLOCK);
124		xcount++;
125	} while (count != fired);
126	evutil_gettimeofday(&te, NULL);
127
128	if (xcount != count) fprintf(stderr, "Xcount: %d, Rcount: %d\n", xcount, count);
129	}
130
131	evutil_timersub(&te, &ts, &te);
132
133	return (&te);
134}
135
136int
137main(int argc, char **argv)
138{
139#ifdef HAVE_SETRLIMIT
140	struct rlimit rl;
141#endif
142	int i, c;
143	struct timeval *tv;
144	evutil_socket_t *cp;
145
146#ifdef _WIN32
147	WSADATA WSAData;
148	WSAStartup(0x101, &WSAData);
149#endif
150	num_pipes = 100;
151	num_active = 1;
152	num_writes = num_pipes;
153	while ((c = getopt(argc, argv, "n:a:w:")) != -1) {
154		switch (c) {
155		case 'n':
156			num_pipes = atoi(optarg);
157			break;
158		case 'a':
159			num_active = atoi(optarg);
160			break;
161		case 'w':
162			num_writes = atoi(optarg);
163			break;
164		default:
165			fprintf(stderr, "Illegal argument \"%c\"\n", c);
166			exit(1);
167		}
168	}
169
170#ifdef HAVE_SETRLIMIT
171	rl.rlim_cur = rl.rlim_max = num_pipes * 2 + 50;
172	if (setrlimit(RLIMIT_NOFILE, &rl) == -1) {
173		perror("setrlimit");
174		exit(1);
175	}
176#endif
177
178	events = calloc(num_pipes, sizeof(struct event));
179	pipes = calloc(num_pipes * 2, sizeof(evutil_socket_t));
180	if (events == NULL || pipes == NULL) {
181		perror("malloc");
182		exit(1);
183	}
184
185	event_init();
186
187	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
188#ifdef USE_PIPES
189		if (pipe(cp) == -1) {
190#else
191		if (evutil_socketpair(AF_UNIX, SOCK_STREAM, 0, cp) == -1) {
192#endif
193			perror("pipe");
194			exit(1);
195		}
196	}
197
198	for (i = 0; i < 25; i++) {
199		tv = run_once();
200		if (tv == NULL)
201			exit(1);
202		fprintf(stdout, "%ld\n",
203			tv->tv_sec * 1000000L + tv->tv_usec);
204	}
205
206	exit(0);
207}
208