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/* nbdkit
* Copyright Red Hat
*
* 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 name of Red Hat 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 RED HAT 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 RED HAT 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.
*/
/* Replacement for poll for platforms which lack this function. */
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#ifndef HAVE_POLL
#include "poll.h"
#ifdef WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#include <windows.h>
#include <errno.h>
/* This is provided by common/utils which hasn't been compiled yet.
* Programs using the poll replacement will need to link to
* libutils.la. XXX
*/
extern int translate_winsock_error (const char *fn, int err);
/* Windows doesn't have poll. It has something called WSAPoll in
* Winsock, but even Microsoft admit it is broken. Gnulib contains an
* elaborate emulation of poll written by Paolo Bonzini, but it's
* distributed under an incompatible license. However Winsock has
* select so we can write a simple (but slow) emulation of poll using
* select.
*/
int
poll (struct pollfd *fds, int n, int timeout)
{
int i, r;
fd_set readfds, writefds;
struct timeval tv, *tvp;
/* https://docs.microsoft.com/en-us/windows/win32/winsock/maximum-number-of-sockets-supported-2 */
if (n >= 64) {
errno = EINVAL;
return -1;
}
FD_ZERO (&readfds);
FD_ZERO (&writefds);
for (i = 0; i < n; ++i) {
if (fds[i].events & POLLIN)
FD_SET (fds[i].fd, &readfds);
if (fds[i].events & POLLOUT)
FD_SET (fds[i].fd, &writefds);
fds[i].revents = 0;
}
if (timeout >= 0) {
tv.tv_sec = timeout / 1000;
tv.tv_usec = timeout % 1000;
tvp = &tv;
}
else
tvp = NULL;
/* Windows ignores the nfds parameter of select. */
r = select (0, &readfds, &writefds, NULL, tvp);
if (r == -1) {
errno = translate_winsock_error ("select", WSAGetLastError ());
return -1;
}
r = 0;
for (i = 0; i < n; ++i) {
if (FD_ISSET (fds[i].fd, &readfds))
fds[i].revents |= POLLIN;
if (FD_ISSET (fds[i].fd, &writefds))
fds[i].revents |= POLLOUT;
if (fds[i].revents != 0)
r++;
}
return r;
}
#else /* !WIN32 */
#error "no replacement poll is available on this platform"
#endif
#endif /* !HAVE_POLL */
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