Commit 1f8962d2 authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont

Revert "Improve Win32 poll replacement (and fix #1949)" et al

Looks like Winsock events operate in a weird and barely adaptable way.
Fixes #2369.

This reverts commit c6ea17a3.
This reverts commit 1a582db1.
This reverts commit 8bda7d72.
This reverts commit acade544.
parent 384ef890
/*****************************************************************************
* poll.c: I/O event multiplexing
*****************************************************************************
* Copyright © 2007-2008 Rémi Denis-Courmont
* Copyright © 2007 Rémi Denis-Courmont
* $Id$
*
* Author: Rémi Denis-Courmont
......@@ -28,7 +28,7 @@
#include <vlc_common.h>
#include <vlc_network.h>
#ifndef WIN32
#ifdef HAVE_POLL
struct pollfd;
int vlc_poll (struct pollfd *fds, unsigned nfds, int timeout)
......@@ -36,80 +36,73 @@ int vlc_poll (struct pollfd *fds, unsigned nfds, int timeout)
(void)fds; (void)nfds; (void)timeout;
abort ();
}
#else
#else /* !HAVE_POLL */
#include <string.h>
#include <stdlib.h>
#include <vlc_network.h>
int vlc_poll (struct pollfd *fds, unsigned nfds, int timeout)
{
WSAEVENT phEvents[nfds];
DWORD val;
vlc_testcancel ();
fd_set rdset, wrset, exset;
struct timeval tv = { 0, 0 };
int val = -1;
FD_ZERO (&rdset);
FD_ZERO (&wrset);
FD_ZERO (&exset);
for (unsigned i = 0; i < nfds; i++)
{
long events = FD_CLOSE;
int fd = fds[i].fd;
if (val < fd)
val = fd;
/* With POSIX, FD_SET & FD_ISSET are not defined if fd is negative or
* bigger or equal than FD_SETSIZE. That is one of the reasons why VLC
* uses poll() rather than select(). Most POSIX systems implement
* fd_set has a bit field with no sanity checks. This is especially bad
* on systems (such as BSD) that have no process open files limit by
* default, such that it is quite feasible to get fd >= FD_SETSIZE.
* The next instructions will result in a buffer overflow if run on
* a POSIX system, and the later FD_ISSET will do undefined memory
* access.
*
* With Winsock, fd_set is a table of integers. This is awfully slow.
* However, FD_SET and FD_ISSET silently and safely discard
* overflows. If it happens we will loose socket events. Note that
* most (if not all) Winsock SOCKET handles are actually bigger than
* FD_SETSIZE in terms of absolute value - they are not POSIX file
* descriptors. From Vista, there is a much nicer WSAPoll(), but Mingw
* is yet to support it.
*
* With BeOS, the situation is unknown (FIXME: document).
*/
if (fds[i].events & POLLIN)
events |= FD_READ | FD_ACCEPT;
FD_SET (fd, &rdset);
if (fds[i].events & POLLOUT)
events |= FD_WRITE;
FD_SET (fd, &wrset);
if (fds[i].events & POLLPRI)
events |= FD_OOB;
fds[i].revents = 0;
FD_SET (fd, &exset);
}
phEvents[i] = WSACreateEvent ();
WSAEventSelect (fds[i].fd, phEvents[i], events);
if (timeout >= 0)
{
div_t d = div (timeout, 1000);
tv.tv_sec = d.quot;
tv.tv_usec = d.rem * 1000;
}
int ret = 0, n = 0;
val = select (val + 1, &rdset, &wrset, &exset,
(timeout >= 0) ? &tv : NULL);
if (val == -1)
return -1;
switch (WaitForMultipleObjectsEx (nfds, phEvents, FALSE, timeout, TRUE))
{
case WAIT_IO_COMPLETION:
WSASetLastError (WSAEINTR);
ret = -1;
break;
case WAIT_TIMEOUT:
ret = 0;
break;
default:
for (unsigned i = 0; i < nfds; i++)
{
WSANETWORKEVENTS events;
if (WSAEnumNetworkEvents (fds[i].fd, phEvents[i], &events))
{
fds[i].revents |= POLLNVAL;
ret = -1;
continue;
int fd = fds[i].fd;
fds[i].revents = (FD_ISSET (fd, &rdset) ? POLLIN : 0)
| (FD_ISSET (fd, &wrset) ? POLLOUT : 0)
| (FD_ISSET (fd, &exset) ? POLLPRI : 0);
}
if (events.lNetworkEvents & FD_CLOSE)
fds[i].revents |= POLLHUP | (fds[i].events & POLLIN);
if (events.lNetworkEvents & FD_ACCEPT)
fds[i].revents |= POLLIN;
if (events.lNetworkEvents & FD_OOB)
fds[i].revents |= POLLPRI;
if (events.lNetworkEvents & FD_READ)
fds[i].revents |= POLLIN;
if (events.lNetworkEvents & FD_WRITE)
{
fds[i].revents |= POLLOUT;
if (events.iErrorCode[FD_WRITE_BIT])
fds[i].revents |= POLLERR;
}
if (fds[i].revents)
n++;
}
if (ret == 0)
ret = n;
}
for (unsigned i = 0; i < nfds; i++)
WSACloseEvent (phEvents[i]);
vlc_testcancel ();
return ret;
return val;
}
#endif /* WIN32 */
#endif /* !HAVE_POLL */
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