Commit e2485c45 authored by Martti Mela's avatar Martti Mela

poll.c: added poll() emulation on select()

darcs-hash:20070206155046-1b897-95e7cb10fc69753e9213e9c9a9ab1f897edfb4f3.gz
parent 5807992b
/* Copyright (C) 1994,1996,1997,1998,1999,2001,2002
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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include "config.h"
#if !HAVE_POLL && HAVE_SELECT && HAVE_POLL_PORT
#include "sofia-sip/su.h"
//extern __typeof(poll) __libc_poll;
#if 1
#include <alloca.h>
#include <string.h>
#include "sofia-sip/su_wait.h"
#ifndef __NFDBITS
#define NBBY 8 /* bits in a byte */
#define __NFDBITS (sizeof(__int32_t) * NBBY) /* bits per mask */
#endif
#undef howmany
#ifndef howmany
#define howmany(x, y) (((x)+((y)-1))/(y)) * sizeof(uint32_t)
#endif
//libc_hidden_proto(memcpy)
//libc_hidden_proto(memset)
//libc_hidden_proto(getdtablesize)
//libc_hidden_proto(select)
/* uClinux 2.0 doesn't have poll, emulate it using select */
/* 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(struct pollfd *fds, nfds_t nfds, int timeout)
{
struct timeval tv;
#if HAVE_ALLOCA_H
static int max_fd_size;
int bytes;
fd_set *rset, *wset, *xset;
#else
fd_set rset[1], wset[1], xset[1];
#endif
struct pollfd *f;
int ready;
int maxfd = 0;
#if HAVE_ALLOCA_H
if (!max_fd_size)
max_fd_size = getdtablesize ();
bytes = howmany (max_fd_size, __NFDBITS);
rset = alloca (bytes);
wset = alloca (bytes);
xset = alloca (bytes);
/* We can't call FD_ZERO, since FD_ZERO only works with sets
of exactly __FD_SETSIZE size. */
memset (rset, 0, bytes);
memset (wset, 0, bytes);
memset (xset, 0, bytes);
#else
FD_ZERO(rset);
FD_ZERO(wset);
FD_ZERO(xset);
#endif
for (f = fds; f < &fds[nfds]; ++f)
{
f->revents = 0;
if (f->fd >= 0)
{
#if HAVE_ALLOCA_H
if (f->fd >= max_fd_size)
{
/* The user provides a file descriptor number which is higher
than the maximum we got from the `getdtablesize' call.
Maybe this is ok so enlarge the arrays. */
fd_set *nrset, *nwset, *nxset;
int nbytes;
max_fd_size = roundup (f->fd, __NFDBITS);
nbytes = howmany (max_fd_size, __NFDBITS);
nrset = alloca (nbytes);
nwset = alloca (nbytes);
nxset = alloca (nbytes);
memset ((char *) nrset + bytes, 0, nbytes - bytes);
memset ((char *) nwset + bytes, 0, nbytes - bytes);
memset ((char *) nxset + bytes, 0, nbytes - bytes);
rset = memcpy (nrset, rset, bytes);
wset = memcpy (nwset, wset, bytes);
xset = memcpy (nxset, xset, bytes);
bytes = nbytes;
}
#else
if (f->fd >= FD_SETSIZE) {
errno = EBADF;
return -1;
}
#endif /* HAVE_ALLOCA_H */
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 % 1000) * 1000;
while (1)
{
ready = select (maxfd + 1, rset, wset, xset,
timeout == -1 ? NULL : &tv);
/* It might be that one or more of the file descriptors is invalid.
We now try to find and mark them and then try again. */
if (ready == -1 && errno == EBADF)
{
struct timeval sngl_tv;
#if HAVE_ALLOCA_H
fd_set *sngl_rset = alloca (bytes);
fd_set *sngl_wset = alloca (bytes);
fd_set *sngl_xset = alloca (bytes);
/* Clear the original set. */
memset (rset, 0, bytes);
memset (wset, 0, bytes);
memset (xset, 0, bytes);
#else
fd_set sngl_rset[1];
fd_set sngl_wset[1];
fd_set sngl_xset[1];
FD_ZERO(rset);
FD_ZERO(wset);
FD_ZERO(xset);
#endif
/* This means we don't wait for input. */
sngl_tv.tv_sec = 0;
sngl_tv.tv_usec = 0;
maxfd = -1;
/* Reset the return value. */
ready = 0;
for (f = fds; f < &fds[nfds]; ++f)
if (f->fd != -1 && (f->events & (POLLIN|POLLOUT|POLLPRI))
&& (f->revents & POLLNVAL) == 0)
{
int n;
#if HAVE_ALLOCA_H
memset (sngl_rset, 0, bytes);
memset (sngl_wset, 0, bytes);
memset (sngl_xset, 0, bytes);
#else
FD_ZERO(rset);
FD_ZERO(wset);
FD_ZERO(xset);
#endif
if (f->events & POLLIN)
FD_SET (f->fd, sngl_rset);
if (f->events & POLLOUT)
FD_SET (f->fd, sngl_wset);
if (f->events & POLLPRI)
FD_SET (f->fd, sngl_xset);
n = select (f->fd + 1, sngl_rset, sngl_wset, sngl_xset,
&sngl_tv);
if (n != -1)
{
/* This descriptor is ok. */
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)
maxfd = f->fd;
if (n > 0)
/* Count it as being available. */
++ready;
}
else if (errno == EBADF)
f->revents |= POLLNVAL;
}
/* Try again. */
continue;
}
break;
}
if (ready > 0)
for (f = fds; f < &fds[nfds]; ++f)
{
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;
}
#endif
#endif
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment