freebsd-skq/lib/libc_r/uthread/uthread_kevent.c
Daniel Eischen 9a6b83bf3b Prevent the thread-safe version of kevent from getting
into an infinite loop when a timeout value is supplied
and the timeout expires.

Reported by:	Dan Nelson <dnelson@emsphone.com>
Reviewed by:	jasone, jlemon
2000-11-09 05:00:06 +00:00

77 lines
2.5 KiB
C

/*-
* Copyright (c) 2000 Jonathan Lemon <jlemon@flugsvamp.com>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 <sys/types.h>
#include <sys/time.h>
#include <sys/event.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
int
kevent(int kq, const struct kevent *changelist, int nchanges,
struct kevent *eventlist, int nevents, const struct timespec *timeout)
{
struct timespec nullts = { 0, 0 };
int rc;
/* Set the wake up time */
_thread_kern_set_timeout(timeout);
rc = _thread_sys_kevent(kq, changelist, nchanges,
eventlist, nevents, &nullts);
if (rc == 0 && (timeout == NULL ||
timeout->tv_sec != 0 || timeout->tv_nsec != 0)) {
/* Save the socket file descriptor: */
_thread_run->data.fd.fd = kq;
_thread_run->data.fd.fname = __FILE__;
_thread_run->data.fd.branch = __LINE__;
do {
/* Reset the interrupted and timeout flags: */
_thread_run->interrupted = 0;
_thread_run->timeout = 0;
_thread_kern_sched_state(PS_FDR_WAIT,
__FILE__, __LINE__);
if (_thread_run->interrupted) {
errno = EINTR;
rc = -1;
break;
}
rc = _thread_sys_kevent(kq, NULL, 0,
eventlist, nevents, &nullts);
} while (rc == 0 && _thread_run->timeout == 0);
}
return (rc);
}
#endif