/* Emulation for poll(2)
Contributed by Paolo Bonzini.
Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
This file is part of gnulib.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/types.h>
#include "poll.h"
#include <errno.h>
#include <limits.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <unistd.h>
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
# include <sys/time.h>
# else
# include <time.h>
# endif
#endif
#ifndef INFTIM
#define INFTIM (-1)
#endif
#ifndef EOVERFLOW
#define EOVERFLOW EINVAL
#endif
int
poll (pfd, nfd, timeout)
struct pollfd *pfd;
nfds_t nfd;
int timeout;
{
fd_set rfds, wfds, efds;
struct timeval tv, *ptv;
int maxfd, rc, happened;
nfds_t i;
char data[64];
#ifdef _SC_OPEN_MAX
if (nfd > sysconf (_SC_OPEN_MAX))
{
errno = EINVAL;
return -1;
}
#else /* !_SC_OPEN_MAX */
#ifdef OPEN_MAX
if (nfd > OPEN_MAX)
{
errno = EINVAL;
return -1;
}
#endif /* OPEN_MAX -- else, no check is needed */
#endif /* !_SC_OPEN_MAX */
/* EFAULT is not necessary to implement, but let's do it in the
simplest case. */
if (!pfd)
{
errno = EFAULT;
return -1;
}
/* convert timeout number into a timeval structure */
ptv = &tv;
if (timeout >= 0)
{
/* return immediately or after timeout */
ptv->tv_sec = timeout / 1000;
ptv->tv_usec = (timeout % 1000) * 1000;
}
else if (timeout == INFTIM)
/* wait forever */
ptv = NULL;
else
{
errno = EINVAL;
return -1;
}
/* create fd sets and determine max fd */
maxfd = -1;
FD_ZERO (&rfds);
FD_ZERO (&wfds);
FD_ZERO (&efds);
for (i = 0; i < nfd; i++)
{
if (pfd[i].fd < 0)
continue;
if (pfd[i].events & (POLLIN | POLLRDNORM))
FD_SET (pfd[i].fd, &rfds);
/* see select(2): "the only exceptional condition detectable
is out-of-band data received on a socket", hence we push
POLLWRBAND events onto wfds instead of efds. */
if (pfd[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND))
FD_SET (pfd[i].fd, &wfds);
if (pfd[i].events & (POLLPRI | POLLRDBAND))
FD_SET (pfd[i].fd, &efds);
if (pfd[i].fd >= maxfd
&& (pfd[i].events & (POLLIN | POLLOUT | POLLPRI
| POLLRDNORM | POLLRDBAND
| POLLWRNORM | POLLWRBAND)))
{
maxfd = pfd[i].fd;
if (maxfd > FD_SETSIZE)
{
errno = EOVERFLOW;
return -1;
}
}
}
/* examine fd sets */
rc = select (maxfd + 1, &rfds, &wfds, &efds, ptv);
/* establish results */
if (rc > 0)
{
rc = 0;
for (i = 0; i < nfd; i++)
{
pfd[i].revents = 0;
if (pfd[i].fd < 0)
continue;
happened = 0;
if (FD_ISSET (pfd[i].fd, &rfds))
{
/* support for POLLHUP. An hung up descriptor does not
increase the return value! */
if (recv (pfd[i].fd, data, 64, MSG_PEEK) == -1)
{
if (errno == ESHUTDOWN || errno == ECONNRESET
|| errno == ECONNABORTED || errno == ENETRESET)
pfd[i].revents |= POLLHUP;
}
else
happened |= POLLIN | POLLRDNORM;
}
if (FD_ISSET (pfd[i].fd, &wfds))
happened |= POLLOUT | POLLWRNORM | POLLWRBAND;
if (FD_ISSET (pfd[i].fd, &efds))
happened |= POLLPRI | POLLRDBAND;
pfd[i].revents |= pfd[i].events & happened;
rc += (happened > 0);
}
}
return rc;
}
