lib/libc_r/uthread/uthread_poll.c

   1 /*
   2  * Copyright (c) 1999 Daniel Eischen <eischen@vigrid.com>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Daniel Eischen.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/lib/libc_r/uthread/uthread_poll.c,v 1.9.2.4 2002/10/22 14:44:03 fjoe Exp $
  33  * $DragonFly: src/lib/libc_r/uthread/uthread_poll.c,v 1.2 2003/06/17 04:26:48 dillon Exp $
  34  */
  35 #include <unistd.h>
  36 #include <errno.h>
  37 #include <string.h>
  38 #include <poll.h>
  39 #include <sys/types.h>
  40 #include <sys/time.h>
  41 #include <sys/fcntl.h>
  42 #include <pthread.h>
  43 #include "pthread_private.h"
  44
  45
  46 int
  47 _poll(struct pollfd *fds, unsigned int nfds, int timeout)
  48 {
  49         struct pthread  *curthread = _get_curthread();
  50         struct timespec ts;
  51         int             numfds = nfds;
  52         int             i, ret = 0;
  53         struct pthread_poll_data data;
  54
  55         if (numfds > _thread_dtablesize) {
  56                 numfds = _thread_dtablesize;
  57         }
  58         /* Check if a timeout was specified: */
  59         if (timeout == INFTIM) {
  60                 /* Wait for ever: */
  61                 _thread_kern_set_timeout(NULL);
  62         } else if (timeout > 0) {
  63                 /* Convert the timeout in msec to a timespec: */
  64                 ts.tv_sec = timeout / 1000;
  65                 ts.tv_nsec = (timeout % 1000) * 1000000;
  66
  67                 /* Set the wake up time: */
  68                 _thread_kern_set_timeout(&ts);
  69         } else if (timeout < 0) {
  70                 /* a timeout less than zero but not == INFTIM is invalid */
  71                 errno = EINVAL;
  72                 return (-1);
  73         }
  74
  75         if (((ret = __sys_poll(fds, numfds, 0)) == 0) && (timeout != 0)) {
  76                 data.nfds = numfds;
  77                 data.fds = fds;
  78
  79                 /*
  80                  * Clear revents in case of a timeout which leaves fds
  81                  * unchanged:
  82                  */
  83                 for (i = 0; i < numfds; i++) {
  84                         fds[i].revents = 0;
  85                 }
  86
  87                 curthread->data.poll_data = &data;
  88                 curthread->interrupted = 0;
  89                 _thread_kern_sched_state(PS_POLL_WAIT, __FILE__, __LINE__);
  90                 if (curthread->interrupted) {
  91                         errno = EINTR;
  92                         ret = -1;
  93                 } else {
  94                         ret = data.nfds;
  95                 }
  96         }
  97
  98         return (ret);
  99 }
 100
 101 int
 102 poll(struct pollfd *fds, unsigned int nfds, int timeout)
 103 {
 104         int ret;
 105
 106         _thread_enter_cancellation_point();
 107         ret = _poll(fds, nfds, timeout);
 108         _thread_leave_cancellation_point();
 109
 110         return ret;
 111 }