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/* Copyright (C) 1994 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <sys/poll.h>
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#include <sys/time.h>
/* Poll the file descriptors described by the NFDS structures starting at
FDS. If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
an event to occur; if TIMEOUT is -1, block until an event occurs.
Returns the number of file descriptors with events, zero if timed out,
or -1 for errors. */
int
poll (fds, nfds, timeout)
struct pollfd *fds;
unsigned long int nfds;
int timeout;
{
struct timeval tv;
fd_set rset, wset, xset;
struct pollfd *f;
int ready;
int maxfd = 0;
FD_ZERO (&rset);
FD_ZERO (&wset);
FD_ZERO (&xset);
for (f = fds; f < &fds[nfds]; ++f)
if (f->fd >= 0)
{
if (f->events & POLLIN)
FD_SET (f->fd, &rset);
if (f->events & POLLOUT)
FD_SET (f->fd, &wset);
if (f->events & POLLPRI)
FD_SET (f->fd, &xset);
if (f->fd > maxfd && (f->events & (POLLIN|POLLOUT|POLLPRI)))
maxfd = f->fd;
}
tv.tv_sec = timeout / 1000;
tv.tv_usec = (timeout + 999) / 1000;
ready = __select (maxfd + 1, &rset, &wset, &xset,
timeout == -1 ? NULL : &tv);
if (ready > 0)
for (f = fds; f < &fds[nfds]; ++f)
{
f->revents = 0;
if (f->fd >= 0)
{
if (FD_ISSET (f->fd, &rset))
f->revents |= POLLIN;
if (FD_ISSET (f->fd, &wset))
f->revents |= POLLOUT;
if (FD_ISSET (f->fd, &xset))
f->revents |= POLLPRI;
}
}
return ready;
}
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