1 /* $NetBSD: poll.c,v 1.3 2008/04/29 05:46:08 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 2003 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Charles Blundell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #include "namespace.h" 34 #include <lib.h> 35 36 #include <sys/types.h> 37 #include <sys/time.h> 38 #include <unistd.h> 39 #include <sys/poll.h> 40 #include <errno.h> 41 42 int 43 poll(struct pollfd *p, nfds_t nfds, int timout) 44 { 45 fd_set rd, wr, except; 46 struct timeval tv; 47 nfds_t i; 48 int highfd, rval; 49 50 /* 51 * select cannot tell us much wrt POLL*BAND, POLLPRI, POLLHUP or 52 * POLLNVAL. 53 */ 54 FD_ZERO(&rd); 55 FD_ZERO(&wr); 56 FD_ZERO(&except); 57 58 highfd = -1; 59 for (i = 0; i < nfds; i++) { 60 p[i].revents = 0; 61 if (p[i].fd < 0) 62 continue; 63 if (p[i].fd >= FD_SETSIZE) { 64 errno = EINVAL; 65 return -1; 66 } 67 if (p[i].fd > highfd) 68 highfd = p[i].fd; 69 70 if (p[i].events & (POLLIN|POLLRDNORM)) 71 FD_SET(p[i].fd, &rd); 72 if (p[i].events & (POLLOUT|POLLWRNORM|POLLWRBAND)) 73 FD_SET(p[i].fd, &wr); 74 if (p[i].events & (POLLRDBAND|POLLPRI)) 75 FD_SET(p[i].fd, &except); 76 } 77 78 tv.tv_sec = timout / 1000; 79 tv.tv_usec = (timout % 1000) * 1000; 80 81 rval = select(highfd + 1, &rd, &wr, &except, 82 timout == -1 ? NULL : &tv); 83 if (rval <= 0) 84 return rval; 85 86 rval = 0; 87 for (i = 0; i < nfds; i++) { 88 if (p[i].fd < 0) 89 continue; 90 if (FD_ISSET(p[i].fd, &rd)) 91 p[i].revents |= p[i].events & (POLLIN|POLLRDNORM); 92 if (FD_ISSET(p[i].fd, &wr)) 93 p[i].revents |= 94 p[i].events & (POLLOUT|POLLWRNORM|POLLWRBAND); 95 if (FD_ISSET(p[i].fd, &except)) 96 p[i].revents |= p[i].events & (POLLRDBAND|POLLPRI); 97 /* XXX: POLLERR/POLLHUP/POLLNVAL? */ 98 if (p[i].revents != 0) 99 rval++; 100 } 101 return rval; 102 } 103