1 /* $OpenBSD: kqueue-pipe.c,v 1.6 2015/08/13 10:13:05 uebayasi 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 #include <sys/types.h> 32 #include <sys/time.h> 33 #include <sys/event.h> 34 #include <stdio.h> 35 #include <unistd.h> 36 #include <fcntl.h> 37 #include <string.h> 38 39 int do_pipe(void); 40 41 int 42 do_pipe(void) 43 { 44 int kq; 45 int n; 46 int fd[2]; 47 struct kevent ev; 48 struct timespec ts; 49 char buf[8000]; 50 51 if (pipe(fd) == -1) 52 return (1); 53 if (fcntl(fd[1], F_SETFL, O_NONBLOCK) == -1) 54 return (1); 55 56 if ((kq = kqueue()) == -1) 57 return (1); 58 59 memset(&ev, 0, sizeof(ev)); 60 ev.ident = fd[1]; 61 ev.filter = EVFILT_WRITE; 62 ev.flags = EV_ADD | EV_ENABLE; 63 n = kevent(kq, &ev, 1, NULL, 0, NULL); 64 if (n == -1) 65 return (1); 66 67 memset(buf, 0, sizeof(buf)); 68 while ((n = write(fd[1], buf, sizeof(buf))) == sizeof(buf)) 69 ; 70 71 ts.tv_sec = 0; 72 ts.tv_nsec = 0; 73 n = kevent(kq, NULL, 0, &ev, 1, &ts); 74 if (n != 0) 75 return (1); 76 77 read(fd[0], buf, sizeof(buf)); 78 79 ts.tv_sec = 0; 80 ts.tv_nsec = 0; 81 n = kevent(kq, NULL, 0, &ev, 1, &ts); 82 if (n == -1 || n == 0) 83 return (1); 84 85 close(fd[0]); 86 close(fd[1]); 87 return (0); 88 } 89