1 /* $OpenBSD: kqueue-pipe.c,v 1.7 2016/09/20 23:05:27 bluhm Exp $ */
2 /*
3 * Copyright 2001 Niels Provos <provos@citi.umich.edu>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by Niels Provos.
17 * 4. The name of the author may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/types.h>
33 #include <sys/time.h>
34 #include <sys/event.h>
35
36 #include <err.h>
37 #include <fcntl.h>
38 #include <stdio.h>
39 #include <string.h>
40 #include <unistd.h>
41
42 #include "main.h"
43
44 int
do_pipe(void)45 do_pipe(void)
46 {
47 int kq;
48 int n;
49 int fd[2];
50 struct kevent ev;
51 struct timespec ts;
52 char buf[8000];
53
54 ASS(pipe(fd) == 0,
55 warn("pipe"));
56 ASS(fcntl(fd[1], F_SETFL, O_NONBLOCK) == 0,
57 warn("fcntl"));
58
59 ASS((kq = kqueue()) >= 0,
60 warn("fcntl"));
61
62 memset(&ev, 0, sizeof(ev));
63 ev.ident = fd[1];
64 ev.filter = EVFILT_WRITE;
65 ev.flags = EV_ADD | EV_ENABLE;
66 n = kevent(kq, &ev, 1, NULL, 0, NULL);
67 ASSX(n != -1);
68
69 memset(buf, 0, sizeof(buf));
70 while ((n = write(fd[1], buf, sizeof(buf))) == sizeof(buf))
71 ;
72
73 ts.tv_sec = 0;
74 ts.tv_nsec = 0;
75 n = kevent(kq, NULL, 0, &ev, 1, &ts);
76 ASSX(n == 0);
77
78 read(fd[0], buf, sizeof(buf));
79
80 ts.tv_sec = 0;
81 ts.tv_nsec = 0;
82 n = kevent(kq, NULL, 0, &ev, 1, &ts);
83 ASSX(n != -1 && n != 0);
84
85 close(fd[0]);
86 close(fd[1]);
87 return (0);
88 }
89