2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 #include <sys/param.h>
37 #include <sys/types.h>
39 #include <sys/fcntl.h>
41 #include "pthread_private.h"
43 __weak_reference(__select, select);
46 _select(int numfds, fd_set * readfds, fd_set * writefds, fd_set * exceptfds,
47 struct timeval * timeout)
49 struct pthread *curthread = _get_curthread();
51 int i, ret = 0, f_wait = 1;
52 int pfd_index, got_events = 0, fd_count = 0;
53 struct pthread_poll_data data;
55 if (numfds > _thread_dtablesize) {
56 numfds = _thread_dtablesize;
58 /* Count the number of file descriptors to be polled: */
59 if (readfds || writefds || exceptfds) {
60 for (i = 0; i < numfds; i++) {
61 if ((readfds && FD_ISSET(i, readfds)) ||
62 (exceptfds && FD_ISSET(i, exceptfds)) ||
63 (writefds && FD_ISSET(i, writefds))) {
70 * Allocate memory for poll data if it hasn't already been
71 * allocated or if previously allocated memory is insufficient.
73 if ((curthread->poll_data.fds == NULL) ||
74 (curthread->poll_data.nfds < fd_count)) {
75 data.fds = (struct pollfd *) realloc(curthread->poll_data.fds,
76 sizeof(struct pollfd) * MAX(128, fd_count));
77 if (data.fds == NULL) {
83 * Note that the threads poll data always
84 * indicates what is allocated, not what is
85 * currently being polled.
87 curthread->poll_data.fds = data.fds;
88 curthread->poll_data.nfds = MAX(128, fd_count);
91 /* Check if a timeout was specified: */
93 if (timeout->tv_sec < 0 ||
94 timeout->tv_usec < 0 || timeout->tv_usec >= 1000000) {
99 /* Convert the timeval to a timespec: */
100 TIMEVAL_TO_TIMESPEC(timeout, &ts);
102 /* Set the wake up time: */
103 _thread_kern_set_timeout(&ts);
104 if (ts.tv_sec == 0 && ts.tv_nsec == 0)
108 _thread_kern_set_timeout(NULL);
112 /* Setup the wait data. */
113 data.fds = curthread->poll_data.fds;
114 data.nfds = fd_count;
117 * Setup the array of pollfds. Optimize this by
118 * running the loop in reverse and stopping when
119 * the number of selected file descriptors is reached.
121 for (i = numfds - 1, pfd_index = fd_count - 1;
122 (i >= 0) && (pfd_index >= 0); i--) {
123 data.fds[pfd_index].events = 0;
124 if (readfds && FD_ISSET(i, readfds)) {
125 data.fds[pfd_index].events = POLLRDNORM;
127 if (exceptfds && FD_ISSET(i, exceptfds)) {
128 data.fds[pfd_index].events |= POLLRDBAND;
130 if (writefds && FD_ISSET(i, writefds)) {
131 data.fds[pfd_index].events |= POLLWRNORM;
133 if (data.fds[pfd_index].events != 0) {
135 * Set the file descriptor to be polled and
136 * clear revents in case of a timeout which
137 * leaves fds unchanged:
139 data.fds[pfd_index].fd = i;
140 data.fds[pfd_index].revents = 0;
144 if (((ret = __sys_poll(data.fds, data.nfds, 0)) == 0) &&
146 curthread->data.poll_data = &data;
147 curthread->interrupted = 0;
148 _thread_kern_sched_state(PS_SELECT_WAIT, __FILE__, __LINE__);
149 if (curthread->interrupted) {
160 for (i = 0; i < fd_count; i++) {
162 * Check the results of the poll and clear
163 * this file descriptor from the fdset if
164 * the requested event wasn't ready.
168 * First check for invalid descriptor.
169 * If found, set errno and return -1.
171 if (data.fds[i].revents & POLLNVAL) {
177 if (readfds != NULL) {
178 if (FD_ISSET(data.fds[i].fd, readfds)) {
179 if ((data.fds[i].revents & (POLLIN
180 | POLLRDNORM | POLLERR
181 | POLLHUP | POLLNVAL)) != 0)
184 FD_CLR(data.fds[i].fd, readfds);
187 if (writefds != NULL) {
188 if (FD_ISSET(data.fds[i].fd, writefds)) {
189 if ((data.fds[i].revents & (POLLOUT
190 | POLLWRNORM | POLLWRBAND | POLLERR
191 | POLLHUP | POLLNVAL)) != 0)
194 FD_CLR(data.fds[i].fd,
198 if (exceptfds != NULL) {
199 if (FD_ISSET(data.fds[i].fd, exceptfds)) {
200 if (data.fds[i].revents & (POLLRDBAND |
204 FD_CLR(data.fds[i].fd,
218 __select(int numfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
219 struct timeval *timeout)
223 _thread_enter_cancellation_point();
224 ret = _select(numfds, readfds, writefds, exceptfds, timeout);
225 _thread_leave_cancellation_point();