freebsd-skq/lib/libc_r/uthread/uthread_select.c
archie af2ae1a6ea Make the libc_r version of select() set the readable or writable
file descriptor bit if poll() returns POLLERR, POLLHUP, or POLLNVAL.
Othewise, it's possible for select() to return successfully but
with no bits set.

Reviewed by:	deischen
MFC after:	3 days
PR:		bin/42175
2002-08-29 21:39:19 +00:00

232 lines
6.5 KiB
C

/*
* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <unistd.h>
#include <errno.h>
#include <poll.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/fcntl.h>
#include <pthread.h>
#include "pthread_private.h"
__weak_reference(__select, select);
int
_select(int numfds, fd_set * readfds, fd_set * writefds, fd_set * exceptfds,
struct timeval * timeout)
{
struct pthread *curthread = _get_curthread();
struct timespec ts;
int i, ret = 0, f_wait = 1;
int pfd_index, got_events = 0, fd_count = 0;
struct pthread_poll_data data;
if (numfds > _thread_dtablesize) {
numfds = _thread_dtablesize;
}
/* Check if a timeout was specified: */
if (timeout) {
if (timeout->tv_sec < 0 ||
timeout->tv_usec < 0 || timeout->tv_usec >= 1000000) {
errno = EINVAL;
return (-1);
}
/* Convert the timeval to a timespec: */
TIMEVAL_TO_TIMESPEC(timeout, &ts);
/* Set the wake up time: */
_thread_kern_set_timeout(&ts);
if (ts.tv_sec == 0 && ts.tv_nsec == 0)
f_wait = 0;
} else {
/* Wait for ever: */
_thread_kern_set_timeout(NULL);
}
/* Count the number of file descriptors to be polled: */
if (readfds || writefds || exceptfds) {
for (i = 0; i < numfds; i++) {
if ((readfds && FD_ISSET(i, readfds)) ||
(exceptfds && FD_ISSET(i, exceptfds)) ||
(writefds && FD_ISSET(i, writefds))) {
fd_count++;
}
}
}
/*
* Allocate memory for poll data if it hasn't already been
* allocated or if previously allocated memory is insufficient.
*/
if ((curthread->poll_data.fds == NULL) ||
(curthread->poll_data.nfds < fd_count)) {
data.fds = (struct pollfd *) realloc(curthread->poll_data.fds,
sizeof(struct pollfd) * MAX(128, fd_count));
if (data.fds == NULL) {
errno = ENOMEM;
ret = -1;
}
else {
/*
* Note that the threads poll data always
* indicates what is allocated, not what is
* currently being polled.
*/
curthread->poll_data.fds = data.fds;
curthread->poll_data.nfds = MAX(128, fd_count);
}
}
if (ret == 0) {
/* Setup the wait data. */
data.fds = curthread->poll_data.fds;
data.nfds = fd_count;
/*
* Setup the array of pollfds. Optimize this by
* running the loop in reverse and stopping when
* the number of selected file descriptors is reached.
*/
for (i = numfds - 1, pfd_index = fd_count - 1;
(i >= 0) && (pfd_index >= 0); i--) {
data.fds[pfd_index].events = 0;
if (readfds && FD_ISSET(i, readfds)) {
data.fds[pfd_index].events = POLLRDNORM;
}
if (exceptfds && FD_ISSET(i, exceptfds)) {
data.fds[pfd_index].events |= POLLRDBAND;
}
if (writefds && FD_ISSET(i, writefds)) {
data.fds[pfd_index].events |= POLLWRNORM;
}
if (data.fds[pfd_index].events != 0) {
/*
* Set the file descriptor to be polled and
* clear revents in case of a timeout which
* leaves fds unchanged:
*/
data.fds[pfd_index].fd = i;
data.fds[pfd_index].revents = 0;
pfd_index--;
}
}
if (((ret = __sys_poll(data.fds, data.nfds, 0)) == 0) &&
(f_wait != 0)) {
curthread->data.poll_data = &data;
curthread->interrupted = 0;
_thread_kern_sched_state(PS_SELECT_WAIT, __FILE__, __LINE__);
if (curthread->interrupted) {
errno = EINTR;
data.nfds = 0;
ret = -1;
} else
ret = data.nfds;
}
}
if (ret >= 0) {
numfds = 0;
for (i = 0; i < fd_count; i++) {
/*
* Check the results of the poll and clear
* this file descriptor from the fdset if
* the requested event wasn't ready.
*/
/*
* First check for invalid descriptor.
* If found, set errno and return -1.
*/
if (data.fds[i].revents & POLLNVAL) {
errno = EBADF;
return -1;
}
got_events = 0;
if (readfds != NULL) {
if (FD_ISSET(data.fds[i].fd, readfds)) {
if ((data.fds[i].revents & (POLLIN
| POLLRDNORM | POLLERR
| POLLHUP | POLLNVAL)) != 0)
got_events++;
else
FD_CLR(data.fds[i].fd, readfds);
}
}
if (writefds != NULL) {
if (FD_ISSET(data.fds[i].fd, writefds)) {
if ((data.fds[i].revents & (POLLOUT
| POLLWRNORM | POLLWRBAND | POLLERR
| POLLHUP | POLLNVAL)) != 0)
got_events++;
else
FD_CLR(data.fds[i].fd,
writefds);
}
}
if (exceptfds != NULL) {
if (FD_ISSET(data.fds[i].fd, exceptfds)) {
if (data.fds[i].revents & (POLLRDBAND |
POLLPRI))
got_events++;
else
FD_CLR(data.fds[i].fd,
exceptfds);
}
}
if (got_events != 0)
numfds+=got_events;
}
ret = numfds;
}
return (ret);
}
int
__select(int numfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
struct timeval *timeout)
{
int ret;
_thread_enter_cancellation_point();
ret = _select(numfds, readfds, writefds, exceptfds, timeout);
_thread_leave_cancellation_point();
return ret;
}