1 /* $NetBSD: cmd_pollpal.c,v 1.1 2020/04/30 00:48:10 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2020 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __RCSID("$NetBSD: cmd_pollpal.c,v 1.1 2020/04/30 00:48:10 christos Exp $");
31
32 #include <sys/mman.h>
33
34 #include <errno.h>
35 #include <err.h>
36 #include <fcntl.h>
37 #include <poll.h>
38 #include <signal.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <stdarg.h>
42 #include <string.h>
43 #include <unistd.h>
44
45 #define BUFFLEN 100
46 #define TIMEOUT 10000
47
48 static int fd;
49
50 static __dead __printflike(2, 3) void
done(int e,const char * msg,...)51 done(int e, const char *msg, ...)
52 {
53 if (msg) {
54 va_list ap;
55
56 va_start(ap, msg);
57 verr(e, msg, ap);
58 /*NOTREACHED*/
59 va_end(ap);
60 }
61 exit(e);
62 }
63
64 static __dead void
handler(int sig)65 handler(int sig)
66 {
67 done(EXIT_SUCCESS, NULL);
68 }
69
70 static const char dev[] = "/dev/pollpal";
71 static const char wbuf[] = "abcdefghijklmnopqrstuvwxyz";
72
73 int
main(int argc,char ** argv)74 main(int argc, char **argv)
75 {
76 struct pollfd fds;
77 ssize_t ret;
78 size_t i;
79 char rbuf[BUFFLEN];
80
81 setprogname(argv[0]);
82
83 fd = open(dev, O_RDWR, 0);
84 if (fd == -1)
85 err(EXIT_FAILURE, "open `%s'", dev);
86
87 fds.fd = fd;
88 fds.events = POLLOUT|POLLIN;
89
90 signal(SIGINT, handler);
91 for (i = 1; i <= 100; i++) {
92 ret = poll(&fds, 1, TIMEOUT);
93 if (ret == -1) {
94 if (errno == EINTR)
95 continue;
96 done(EXIT_FAILURE, "poll");
97 }
98 printf("Poll_executing %zu times\n", i);
99 if (ret == 0) {
100 printf("%d seconds elapsed \n.TIMEOUT.\n",
101 TIMEOUT / 1000);
102 done(EXIT_SUCCESS, NULL);
103 }
104
105 if (fds.revents & (POLLERR | POLLHUP | POLLNVAL))
106 done(EXIT_FAILURE, "ERR|HUP|NVAL");
107
108 if (fds.revents & POLLOUT) {
109 do {
110 ret = write(fd, wbuf, sizeof(wbuf) - 1);
111 } while (ret == -1 && errno == EINTR);
112
113 if (ret == -1) {
114 done(EXIT_FAILURE, "write");
115 }
116 printf("Wrote %zd byte\n", ret);
117 }
118 if (fds.revents & POLLIN) {
119 memset(rbuf, 0, BUFFLEN);
120 do {
121 ret = read(fd, rbuf, BUFFLEN);
122 } while (ret == -1 && errno == EINTR);
123 if (ret == -1) {
124 done(EXIT_FAILURE, "read");
125 }
126 printf("Read %zd bytes\n", ret);
127 }
128 }
129 done(EXIT_SUCCESS, NULL);
130 }
131