1/*
2 * Copyright 2003 Niels Provos <provos@citi.umich.edu>
3 * All rights reserved.
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#ifdef HAVE_CONFIG_H
37#include "config.h"
38#endif
39
40#include <sys/types.h>
41#include <sys/stat.h>
42#include <sys/time.h>
43#ifdef WIN32
44#include <windows.h>
45#else
46#include <sys/socket.h>
47#include <signal.h>
48#include <sys/resource.h>
49#endif
50#include <fcntl.h>
51#include <stdlib.h>
52#include <stdio.h>
53#include <string.h>
54#include <unistd.h>
55#include <errno.h>
56
57#include <event.h>
58#include <evutil.h>
59
60
61static int count, writes, fired;
62static int *pipes;
63static int num_pipes, num_active, num_writes;
64static struct event *events;
65
66static void
67read_cb(int fd, short which, void *arg)
68{
69	long idx = (long) arg, widx = idx + 1;
70	u_char ch;
71
72	count += read(fd, &ch, sizeof(ch));
73	if (writes) {
74		if (widx >= num_pipes)
75			widx -= num_pipes;
76		write(pipes[2 * widx + 1], "e", 1);
77		writes--;
78		fired++;
79	}
80}
81
82static struct timeval *
83run_once(void)
84{
85	int *cp, space;
86	long i;
87	static struct timeval ts, te;
88
89	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
90		event_del(&events[i]);
91		event_set(&events[i], cp[0], EV_READ | EV_PERSIST, read_cb, (void *) i);
92		event_add(&events[i], NULL);
93	}
94
95	event_loop(EVLOOP_ONCE | EVLOOP_NONBLOCK);
96
97	fired = 0;
98	space = num_pipes / num_active;
99	space = space * 2;
100	for (i = 0; i < num_active; i++, fired++)
101		write(pipes[i * space + 1], "e", 1);
102
103	count = 0;
104	writes = num_writes;
105	{ int xcount = 0;
106	gettimeofday(&ts, NULL);
107	do {
108		event_loop(EVLOOP_ONCE | EVLOOP_NONBLOCK);
109		xcount++;
110	} while (count != fired);
111	gettimeofday(&te, NULL);
112
113	if (xcount != count) fprintf(stderr, "Xcount: %d, Rcount: %d\n", xcount, count);
114	}
115
116	evutil_timersub(&te, &ts, &te);
117
118	return (&te);
119}
120
121int
122main (int argc, char **argv)
123{
124#ifndef WIN32
125	struct rlimit rl;
126#endif
127	int i, c;
128	struct timeval *tv;
129	int *cp;
130
131	num_pipes = 100;
132	num_active = 1;
133	num_writes = num_pipes;
134	while ((c = getopt(argc, argv, "n:a:w:")) != -1) {
135		switch (c) {
136		case 'n':
137			num_pipes = atoi(optarg);
138			break;
139		case 'a':
140			num_active = atoi(optarg);
141			break;
142		case 'w':
143			num_writes = atoi(optarg);
144			break;
145		default:
146			fprintf(stderr, "Illegal argument \"%c\"\n", c);
147			exit(1);
148		}
149	}
150
151#ifndef WIN32
152	rl.rlim_cur = rl.rlim_max = num_pipes * 2 + 50;
153	if (setrlimit(RLIMIT_NOFILE, &rl) == -1) {
154		perror("setrlimit");
155		exit(1);
156	}
157#endif
158
159	events = calloc(num_pipes, sizeof(struct event));
160	pipes = calloc(num_pipes * 2, sizeof(int));
161	if (events == NULL || pipes == NULL) {
162		perror("malloc");
163		exit(1);
164	}
165
166	event_init();
167
168	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
169#ifdef USE_PIPES
170		if (pipe(cp) == -1) {
171#else
172		if (evutil_socketpair(AF_UNIX, SOCK_STREAM, 0, cp) == -1) {
173#endif
174			perror("pipe");
175			exit(1);
176		}
177	}
178
179	for (i = 0; i < 25; i++) {
180		tv = run_once();
181		if (tv == NULL)
182			exit(1);
183		fprintf(stdout, "%ld\n",
184			tv->tv_sec * 1000000L + tv->tv_usec);
185	}
186
187	exit(0);
188}
189