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#include <event.h>
61#include <evutil.h>
62
63static int count, writes, fired;
64static int *pipes;
65static int num_pipes, num_active, num_writes;
66static struct event *events;
67
68
69static void
70read_cb(evutil_socket_t fd, short which, void *arg)
71{
72	long idx = (long) arg, widx = idx + 1;
73	u_char ch;
74
75	count += recv(fd, (char*)&ch, sizeof(ch), 0);
76	if (writes) {
77		if (widx >= num_pipes)
78			widx -= num_pipes;
79		send(pipes[2 * widx + 1], "e", 1, 0);
80		writes--;
81		fired++;
82	}
83}
84
85static struct timeval *
86run_once(void)
87{
88	int *cp, space;
89	long i;
90	static struct timeval ts, te;
91
92	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
93		if (event_initialized(&events[i]))
94			event_del(&events[i]);
95		event_set(&events[i], cp[0], EV_READ | EV_PERSIST, read_cb, (void *) i);
96		event_add(&events[i], NULL);
97	}
98
99	event_loop(EVLOOP_ONCE | EVLOOP_NONBLOCK);
100
101	fired = 0;
102	space = num_pipes / num_active;
103	space = space * 2;
104	for (i = 0; i < num_active; i++, fired++)
105		send(pipes[i * space + 1], "e", 1, 0);
106
107	count = 0;
108	writes = num_writes;
109	{ int xcount = 0;
110	evutil_gettimeofday(&ts, NULL);
111	do {
112		event_loop(EVLOOP_ONCE | EVLOOP_NONBLOCK);
113		xcount++;
114	} while (count != fired);
115	evutil_gettimeofday(&te, NULL);
116
117	if (xcount != count) fprintf(stderr, "Xcount: %d, Rcount: %d\n", xcount, count);
118	}
119
120	evutil_timersub(&te, &ts, &te);
121
122	return (&te);
123}
124
125int
126main(int argc, char **argv)
127{
128#ifndef WIN32
129	struct rlimit rl;
130#endif
131	int i, c;
132	struct timeval *tv;
133	int *cp;
134
135#ifdef WIN32
136	WSADATA WSAData;
137	WSAStartup(0x101, &WSAData);
138#endif
139	num_pipes = 100;
140	num_active = 1;
141	num_writes = num_pipes;
142	while ((c = getopt(argc, argv, "n:a:w:")) != -1) {
143		switch (c) {
144		case 'n':
145			num_pipes = atoi(optarg);
146			break;
147		case 'a':
148			num_active = atoi(optarg);
149			break;
150		case 'w':
151			num_writes = atoi(optarg);
152			break;
153		default:
154			fprintf(stderr, "Illegal argument \"%c\"\n", c);
155			exit(1);
156		}
157	}
158
159#ifndef WIN32
160	rl.rlim_cur = rl.rlim_max = num_pipes * 2 + 50;
161	if (setrlimit(RLIMIT_NOFILE, &rl) == -1) {
162		perror("setrlimit");
163		exit(1);
164	}
165#endif
166
167	events = calloc(num_pipes, sizeof(struct event));
168	pipes = calloc(num_pipes * 2, sizeof(int));
169	if (events == NULL || pipes == NULL) {
170		perror("malloc");
171		exit(1);
172	}
173
174	event_init();
175
176	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
177#ifdef USE_PIPES
178		if (pipe(cp) == -1) {
179#else
180		if (evutil_socketpair(AF_UNIX, SOCK_STREAM, 0, cp) == -1) {
181#endif
182			perror("pipe");
183			exit(1);
184		}
185	}
186
187	for (i = 0; i < 25; i++) {
188		tv = run_once();
189		if (tv == NULL)
190			exit(1);
191		fprintf(stdout, "%ld\n",
192			tv->tv_sec * 1000000L + tv->tv_usec);
193	}
194
195	exit(0);
196}
197