xref: /freebsd/contrib/ntp/sntp/libevent/test/bench_cascade.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /*
2  * Copyright 2007-2012 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  * 4. 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  */
27 
28 #include "event2/event-config.h"
29 
30 #include <sys/types.h>
31 #include <sys/stat.h>
32 #ifdef EVENT__HAVE_SYS_TIME_H
33 #include <sys/time.h>
34 #endif
35 #ifdef _WIN32
36 #define WIN32_LEAN_AND_MEAN
37 #include <windows.h>
38 #include <getopt.h>
39 #else /* _WIN32 */
40 #include <sys/socket.h>
41 #include <sys/resource.h>
42 #endif
43 #include <signal.h>
44 #include <fcntl.h>
45 #include <stdlib.h>
46 #include <stdio.h>
47 #include <string.h>
48 #ifdef EVENT__HAVE_UNISTD_H
49 #include <unistd.h>
50 #endif
51 #include <errno.h>
52 #include <event.h>
53 #include <evutil.h>
54 
55 /*
56  * This benchmark tests how quickly we can propagate a write down a chain
57  * of socket pairs.  We start by writing to the first socket pair and all
58  * events will fire subsequently until the last socket pair has been reached
59  * and the benchmark terminates.
60  */
61 
62 static int fired;
63 static evutil_socket_t *pipes;
64 static struct event *events;
65 
66 static void
67 read_cb(evutil_socket_t fd, short which, void *arg)
68 {
69 	char ch;
70 	evutil_socket_t sock = (evutil_socket_t)(ev_intptr_t)arg;
71 
72 	(void) recv(fd, &ch, sizeof(ch), 0);
73 	if (sock >= 0) {
74 		if (send(sock, "e", 1, 0) < 0)
75 			perror("send");
76 	}
77 	fired++;
78 }
79 
80 static struct timeval *
81 run_once(int num_pipes)
82 {
83 	int i;
84 	evutil_socket_t *cp;
85 	static struct timeval ts, te, tv_timeout;
86 
87 	events = (struct event *)calloc(num_pipes, sizeof(struct event));
88 	pipes = (evutil_socket_t *)calloc(num_pipes * 2, sizeof(evutil_socket_t));
89 
90 	if (events == NULL || pipes == NULL) {
91 		perror("malloc");
92 		exit(1);
93 	}
94 
95 	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
96 		if (evutil_socketpair(AF_UNIX, SOCK_STREAM, 0, cp) == -1) {
97 			perror("socketpair");
98 			exit(1);
99 		}
100 	}
101 
102 	/* measurements includes event setup */
103 	evutil_gettimeofday(&ts, NULL);
104 
105 	/* provide a default timeout for events */
106 	evutil_timerclear(&tv_timeout);
107 	tv_timeout.tv_sec = 60;
108 
109 	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
110 		evutil_socket_t fd = i < num_pipes - 1 ? cp[3] : -1;
111 		event_set(&events[i], cp[0], EV_READ, read_cb,
112 		    (void *)(ev_intptr_t)fd);
113 		event_add(&events[i], &tv_timeout);
114 	}
115 
116 	fired = 0;
117 
118 	/* kick everything off with a single write */
119 	if (send(pipes[1], "e", 1, 0) < 0)
120 		perror("send");
121 
122 	event_dispatch();
123 
124 	evutil_gettimeofday(&te, NULL);
125 	evutil_timersub(&te, &ts, &te);
126 
127 	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
128 		event_del(&events[i]);
129 		evutil_closesocket(cp[0]);
130 		evutil_closesocket(cp[1]);
131 	}
132 
133 	free(pipes);
134 	free(events);
135 
136 	return (&te);
137 }
138 
139 int
140 main(int argc, char **argv)
141 {
142 #ifdef EVENT__HAVE_SETRLIMIT
143 	struct rlimit rl;
144 #endif
145 	int i, c;
146 	struct timeval *tv;
147 
148 	int num_pipes = 100;
149 #ifdef _WIN32
150 	WSADATA WSAData;
151 	WSAStartup(0x101, &WSAData);
152 #endif
153 
154 	while ((c = getopt(argc, argv, "n:")) != -1) {
155 		switch (c) {
156 		case 'n':
157 			num_pipes = atoi(optarg);
158 			break;
159 		default:
160 			fprintf(stderr, "Illegal argument \"%c\"\n", c);
161 			exit(1);
162 		}
163 	}
164 
165 #ifdef EVENT__HAVE_SETRLIMIT
166 	rl.rlim_cur = rl.rlim_max = num_pipes * 2 + 50;
167 	if (setrlimit(RLIMIT_NOFILE, &rl) == -1) {
168 		perror("setrlimit");
169 		exit(1);
170 	}
171 #endif
172 
173 	event_init();
174 
175 	for (i = 0; i < 25; i++) {
176 		tv = run_once(num_pipes);
177 		if (tv == NULL)
178 			exit(1);
179 		fprintf(stdout, "%ld\n",
180 			tv->tv_sec * 1000000L + tv->tv_usec);
181 	}
182 
183 #ifdef _WIN32
184 	WSACleanup();
185 #endif
186 
187 	exit(0);
188 }
189