blob: 73a85248031ef4f1ac7a7579ab16eb22f8342b04 [file] [log] [blame]
Darren Tucker8d36f9a2014-02-06 10:44:13 +11001/* $Id: bsd-poll.c,v 1.6 2014/02/05 23:44:13 dtucker Exp $ */
Darren Tuckerfebf0f52007-06-25 22:15:12 +10002
3/*
4 * Copyright (c) 2004, 2005, 2007 Darren Tucker (dtucker at zip com au).
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include "includes.h"
Darren Tucker7ec87332008-02-29 13:57:47 +110020#if !defined(HAVE_POLL)
Darren Tuckerfebf0f52007-06-25 22:15:12 +100021
Darren Tucker8c333ec2013-11-08 21:12:58 +110022#include <sys/types.h>
23#include <sys/time.h>
Darren Tuckerfebf0f52007-06-25 22:15:12 +100024#ifdef HAVE_SYS_SELECT_H
25# include <sys/select.h>
26#endif
27
Darren Tuckerfebf0f52007-06-25 22:15:12 +100028#include <errno.h>
Darren Tucker8c333ec2013-11-08 21:12:58 +110029#include <stdlib.h>
30#include <unistd.h>
Darren Tuckerfebf0f52007-06-25 22:15:12 +100031#include "bsd-poll.h"
32
33/*
34 * A minimal implementation of poll(2), built on top of select(2).
35 *
36 * Only supports POLLIN and POLLOUT flags in pfd.events, and POLLIN, POLLOUT
37 * and POLLERR flags in revents.
38 *
39 * Supports pfd.fd = -1 meaning "unused" although it's not standard.
40 */
41
42int
43poll(struct pollfd *fds, nfds_t nfds, int timeout)
44{
45 nfds_t i;
46 int saved_errno, ret, fd, maxfd = 0;
47 fd_set *readfds = NULL, *writefds = NULL, *exceptfds = NULL;
48 size_t nmemb;
49 struct timeval tv, *tvp = NULL;
50
51 for (i = 0; i < nfds; i++) {
Darren Tucker661f63b2008-08-30 07:32:37 +100052 fd = fds[i].fd;
Darren Tuckerfebf0f52007-06-25 22:15:12 +100053 if (fd >= FD_SETSIZE) {
54 errno = EINVAL;
55 return -1;
56 }
Darren Tucker661f63b2008-08-30 07:32:37 +100057 maxfd = MAX(maxfd, fd);
Darren Tuckerfebf0f52007-06-25 22:15:12 +100058 }
59
60 nmemb = howmany(maxfd + 1 , NFDBITS);
61 if ((readfds = calloc(nmemb, sizeof(fd_mask))) == NULL ||
62 (writefds = calloc(nmemb, sizeof(fd_mask))) == NULL ||
63 (exceptfds = calloc(nmemb, sizeof(fd_mask))) == NULL) {
64 saved_errno = ENOMEM;
65 ret = -1;
66 goto out;
67 }
68
69 /* populate event bit vectors for the events we're interested in */
70 for (i = 0; i < nfds; i++) {
71 fd = fds[i].fd;
72 if (fd == -1)
73 continue;
74 if (fds[i].events & POLLIN) {
75 FD_SET(fd, readfds);
76 FD_SET(fd, exceptfds);
77 }
78 if (fds[i].events & POLLOUT) {
79 FD_SET(fd, writefds);
80 FD_SET(fd, exceptfds);
81 }
82 }
83
84 /* poll timeout is msec, select is timeval (sec + usec) */
85 if (timeout >= 0) {
86 tv.tv_sec = timeout / 1000;
87 tv.tv_usec = (timeout % 1000) * 1000;
88 tvp = &tv;
89 }
90
91 ret = select(maxfd + 1, readfds, writefds, exceptfds, tvp);
92 saved_errno = errno;
93
94 /* scan through select results and set poll() flags */
95 for (i = 0; i < nfds; i++) {
96 fd = fds[i].fd;
97 fds[i].revents = 0;
98 if (fd == -1)
99 continue;
100 if (FD_ISSET(fd, readfds)) {
101 fds[i].revents |= POLLIN;
102 }
103 if (FD_ISSET(fd, writefds)) {
104 fds[i].revents |= POLLOUT;
105 }
106 if (FD_ISSET(fd, exceptfds)) {
107 fds[i].revents |= POLLERR;
108 }
109 }
110
111out:
Darren Tucker8d36f9a2014-02-06 10:44:13 +1100112 free(readfds);
113 free(writefds);
114 free(exceptfds);
Darren Tuckerfebf0f52007-06-25 22:15:12 +1000115 if (ret == -1)
116 errno = saved_errno;
117 return ret;
118}
119#endif