src/common/fakepoll.c
/* $Id$ */
/*
* fakepoll.c
*
* On systems where 'poll' doesn't exist, fake it with 'select'.
*
* Copyright (c) 2001-2003, Nick Mathewson <nickm@freehaven.net>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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.
*
* * Neither the names of the copyright owners nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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.
*/
#include "defines.h"
#include "config.h"
#include "common.h"
/* prevents ISO C error */
#ifdef USE_FAKE_POLL
static void
FAKEPOLL(int stop)
{
if (!stop)
FAKEPOLL(1);
return;
}
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#if _MSC_VER > 1300
#include <winsock2.h>
#include <ws2tcpip.h>
#elif defined(_MSC_VER)
#include <winsock.h>
#endif
/* by default, windows handles only 64 fd's */
#if defined(MS_WINDOWS) && !defined(FD_SETSIZE)
#define FD_SETSIZE MAXCONNECTIONS
#endif
#include "util.h"
/**
* custom version of poll() using select() in the backend
* only used if you don't actually have poll on your system.
*/
int
poll(struct pollfd *ufds, unsigned int nfds, int timeout)
{
int idx, maxfd, fd;
int r;
#ifdef MS_WINDOWS
int any_fds_set = 0;
#endif
fd_set readfds, writefds, exceptfds;
#ifdef USING_FAKE_TIMEVAL
#undef timeval
#undef tv_sec
#undef tv_usec
#endif
struct timeval _timeout;
_timeout.tv_sec = timeout / 1000;
_timeout.tv_usec = (timeout % 1000) * 1000;
FD_ZERO(&readfds);
FD_ZERO(&writefds);
FD_ZERO(&exceptfds);
maxfd = -1;
for (idx = 0; idx < nfds; ++idx) {
ufds[idx].revents = 0;
fd = ufds[idx].fd;
if (fd > maxfd) {
maxfd = fd;
#ifdef MS_WINDOWS
any_fds_set = 1;
#endif
}
if (ufds[idx].events & POLLIN)
FD_SET(fd, &readfds);
if (ufds[idx].events & POLLOUT)
FD_SET(fd, &writefds);
FD_SET(fd, &exceptfds);
}
#ifdef MS_WINDOWS
if (!any_fds_set) {
Sleep(timeout);
return 0;
}
#endif
r = select(maxfd + 1, &readfds, &writefds, &exceptfds, timeout == -1 ? NULL : &_timeout);
if (r <= 0)
return r;
r = 0;
for (idx = 0; idx < nfds; ++idx) {
fd = ufds[idx].fd;
if (FD_ISSET(fd, &readfds))
ufds[idx].revents |= POLLIN;
if (FD_ISSET(fd, &writefds))
ufds[idx].revents |= POLLOUT;
if (FD_ISSET(fd, &exceptfds))
ufds[idx].revents |= POLLERR;
if (ufds[idx].revents)
++r;
}
return r;
}
#endif