/* Emulation for poll(2)
Contributed by Paolo Bonzini.
Copyright 2001, 2002, 2003, 2006, 2007, 2008 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
#include <config.h>
#include <sys/types.h>
#include "poll.h"
#include <errno.h>
#include <limits.h>
#ifdef __MSVCRT__
#include <windows.h>
#include <winsock2.h>
#include <io.h>
#include <stdio.h>
#include <conio.h>
#else
#include <sys/socket.h>
#include <sys/select.h>
#include <unistd.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_FILIO_H
#include <sys/filio.h>
#endif
#include <sys/time.h>
#include <time.h>
#ifndef INFTIM
#define INFTIM (-1)
#endif
/* BeOS does not have MSG_PEEK. */
#ifndef MSG_PEEK
#define MSG_PEEK 0
#endif
#ifdef __MSVCRT__
/* Declare data structures for ntdll functions. */
typedef struct _FILE_PIPE_LOCAL_INFORMATION {
ULONG NamedPipeType;
ULONG NamedPipeConfiguration;
ULONG MaximumInstances;
ULONG CurrentInstances;
ULONG InboundQuota;
ULONG ReadDataAvailable;
ULONG OutboundQuota;
ULONG WriteQuotaAvailable;
ULONG NamedPipeState;
ULONG NamedPipeEnd;
} FILE_PIPE_LOCAL_INFORMATION, *PFILE_PIPE_LOCAL_INFORMATION;
typedef struct _IO_STATUS_BLOCK
{
union u {
NTSTATUS Status;
PVOID Pointer;
};
ULONG_PTR Information;
} IO_STATUS_BLOCK, *PIO_STATUS_BLOCK;
#define FilePipeLocalInformation 24
typedef NTSTATUS (NTAPI *PNtQueryInformationFile)
(HANDLE, IO_STATUS_BLOCK *, VOID *, ULONG, FILE_INFORMATION_CLASS);
#ifndef PIPE_BUF
#define PIPE_BUF 512
#endif
/* Compute revents values for file handle H. */
static int
win32_compute_revents (HANDLE h, int sought)
{
int i, ret, happened;
INPUT_RECORD *irbuffer;
DWORD avail, nbuffer;
IO_STATUS_BLOCK iosb;
FILE_PIPE_LOCAL_INFORMATION fpli;
static PNtQueryInformationFile NtQueryInformationFile;
ret = WaitForSingleObject (h, 0);
if (ret != WAIT_OBJECT_0)
return sought & (POLLOUT | POLLWRNORM | POLLWRBAND);
switch (GetFileType (h))
{
case FILE_TYPE_PIPE:
if (!NtQueryInformationFile)
NtQueryInformationFile = (PNtQueryInformationFile)
GetProcAddress (GetModuleHandle ("ntdll.dll"),
"NtQueryInformationFile");
happened = 0;
if (!PeekNamedPipe (h, NULL, 0, NULL, &avail, NULL))
return POLLERR;
if (avail)
happened |= sought & (POLLIN | POLLRDNORM);
memset (&iosb, 0, sizeof (iosb));
memset (&fpli, 0, sizeof (fpli));
/* If NtQueryInformationFile fails, optimistically assume the pipe is
writable. This could happen on Win9x, because NtQueryInformationFile
is not available, or if we inherit a pipe that doesn't permit
FILE_READ_ATTRIBUTES access on the write end (I think this should
not happen since WinXP SP2; WINE seems fine too). Otherwise,
ensure that enough space is available for atomic writes. */
if (NtQueryInformationFile (h, &iosb, &fpli, sizeof (fpli),
FilePipeLocalInformation)
|| fpli.WriteQuotaAvailable >= PIPE_BUF
|| (fpli.OutboundQuota < PIPE_BUF &&
fpli.WriteQuotaAvailable == fpli.OutboundQuota))
happened |= sought & (POLLOUT | POLLWRNORM | POLLWRBAND);
return happened;
case FILE_TYPE_CHAR:
nbuffer = avail = 0;
bRet = GetNumberOfConsoleInputEvents (h, &nbuffer);
if (!bRet || nbuffer == 0)
return POLLHUP;
irbuffer = (INPUT_RECORD *) alloca (nbuffer * sizeof (INPUT_RECORD));
bRet = PeekConsoleInput (h, irbuffer, nbuffer, &avail);
if (!bRet || avail == 0)
return POLLHUP;
for (i = 0; i < avail; i++)
if (irbuffer[i].EventType == KEY_EVENT)
return sought & ~(POLLPRI | POLLRDBAND);
return sought & (POLLOUT | POLLWRNORM | POLLWRBAND);
default:
return sought & ~(POLLPRI | POLLRDBAND);
}
}
/* Convert fd_sets returned by select into revents values. */
static int
win32_compute_revents_socket (SOCKET h, int sought,
fd_set *rfds, fd_set *wfds, fd_set *efds)
{
int happened = 0;
if (FD_ISSET (h, rfds))
{
int r, error;
char data[64];
WSASetLastError (0);
r = recv (h, data, sizeof (data), MSG_PEEK);
error = WSAGetLastError ();
WSASetLastError (0);
if (r == 0)
happened |= POLLHUP;
/* If the event happened on an unconnected server socket,
that's fine. */
else if (r > 0 || ( /* (r == -1) && */ error == ENOTCONN))
happened |= (POLLIN | POLLRDNORM) & sought;
/* Distinguish hung-up sockets from other errors. */
else if (error == WSAESHUTDOWN || error == WSAECONNRESET
|| error == WSAECONNABORTED || error == WSAENETRESET)
happened |= POLLHUP;
else
happened |= POLLERR;
}
if (FD_ISSET (h, wfds))
happened |= (POLLOUT | POLLWRNORM | POLLWRBAND) & sought;
if (FD_ISSET (h, efds))
happened |= (POLLPRI | POLLRDBAND) & sought;
return happened;
}
#else /* !MinGW */
/* Convert select(2) returned fd_sets into poll(2) revents values. */
static int
compute_revents (int fd, int sought, fd_set *rfds, fd_set *wfds, fd_set *efds)
{
int happened;
if (FD_ISSET (fd, rfds))
{
int r;
int socket_errno;
#if defined __MACH__ && defined __APPLE__
/* There is a bug in Mac OS X that causes it to ignore MSG_PEEK
for some kinds of descriptors. Detect if this descriptor is a
connected socket, a server socket, or something else using a
0-byte recv, and use ioctl(2) to detect POLLHUP. */
r = recv (fd, NULL, 0, MSG_PEEK);
socket_errno = (r < 0) ? errno : 0;
if (r == 0 || socket_errno == ENOTSOCK)
ioctl (fd, FIONREAD, &r);
#else
char data[64];
r = recv (fd, data, sizeof (data), MSG_PEEK);
socket_errno = (r < 0) ? errno : 0;
#endif
if (r == 0)
happened |= POLLHUP;
/* If the event happened on an unconnected server socket,
that's fine. */
else if (r > 0 || ( /* (r == -1) && */ socket_errno == ENOTCONN))
happened |= (POLLIN | POLLRDNORM) & sought;
/* Distinguish hung-up sockets from other errors. */
else if (socket_errno == ESHUTDOWN || socket_errno == ECONNRESET
|| socket_errno == ECONNABORTED || socket_errno == ENETRESET)
happened |= POLLHUP;
else
happened |= POLLERR;
}
if (FD_ISSET (fd, wfds))
happened |= (POLLOUT | POLLWRNORM | POLLWRBAND) & sought;
if (FD_ISSET (fd, efds))
happened |= (POLLPRI | POLLRDBAND) & sought;
return happened;
}
#endif /* !MinGW */
int
poll (pfd, nfd, timeout)
struct pollfd *pfd;
nfds_t nfd;
int timeout;
{
#ifndef __MSVCRT__
fd_set rfds, wfds, efds;
struct timeval tv;
struct timeval *ptv;
int maxfd, rc;
nfds_t i;
#ifdef _SC_OPEN_MAX
static int sc_open_max = -1;
if (nfd < 0
|| (nfd > sc_open_max
&& (sc_open_max != -1
|| nfd > (sc_open_max = sysconf (_SC_OPEN_MAX)))))
{
errno = EINVAL;
return -1;
}
#else /* !_SC_OPEN_MAX */
#ifdef OPEN_MAX
if (nfd < 0 || 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 */
if (timeout == 0)
{
ptv = &tv;
ptv->tv_sec = 0;
ptv->tv_usec = 0;
}
else if (timeout > 0)
{
ptv = &tv;
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;
/* Windows use a linear array of sockets (of size FD_SETSIZE). The
descriptor value is not used to address the array. */
#if defined __CYGWIN__ || (!defined _WIN32 && !defined __WIN32__)
if (maxfd > FD_SETSIZE)
{
errno = EOVERFLOW;
return -1;
}
#endif
}
}
/* examine fd sets */
rc = select (maxfd + 1, &rfds, &wfds, &efds, ptv);
if (rc < 0)
return rc;
/* establish results */
rc = 0;
for (i = 0; i < nfd; i++)
if (pfd[i].fd < 0)
pfd[i].revents = 0;
else
{
int happened = compute_revents (pfd[i].fd, pfd[i].events,
&rfds, &wfds, &efds);
if (happened)
{
pfd[i].revents = happened;
rc++;
}
}
return rc;
#else
fd_set rfds, wfds, efds;
static struct timeval tv0;
struct timeval tv = { 0, 0 };
struct timeval *ptv;
static HANDLE hEvent;
HANDLE handle_array[FD_SET_SIZE + 2];
DWORD ret, wait_timeout, nhandles;
int nsock;
BOOL bRet;
MSG msg;
char sockbuf[256];
int rc;
nfds_t i;
if (nfd < 0 || nfd > FD_SET_SIZE || timeout < 0)
{
errno = EINVAL;
return -1;
}
if (!hEvent)
hEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
handle_array[0] = hEvent;
nhandles = 1;
nsock = 0;
/* Classify socket handles and create fd sets. */
FD_ZERO (&rfds);
FD_ZERO (&wfds);
FD_ZERO (&efds);
for (i = 0; i < nfd; i++)
{
if (pfd[i].fd < 0)
continue;
h = (HANDLE) _get_osfhandle (i);
assert (h != NULL);
optlen = sizeof(sockbuf);
if ((getsockopt ((SOCKET) h, SOL_SOCKET, SO_TYPE, sockbuf, &optlen)
!= SOCKET_ERROR)
|| WSAGetLastError() != WSAENOTSOCK)
{
int ev = 0;
/* see above; socket handles are mapped onto select. */
if (pfd[i].events & (POLLIN | POLLRDNORM))
{
FD_SET (pfd[i].fd, &rfds);
ev |= FD_READ | FD_ACCEPT;
}
if (pfd[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND))
{
FD_SET (pfd[i].fd, &wfds);
ev |= FD_WRITE | FD_CONNECT;
}
if (pfd[i].events & (POLLPRI | POLLRDBAND))
{
FD_SET (pfd[i].fd, &efds);
ev |= FD_OOB;
}
if (ev)
{
WSAEventSelect ((SOCKET) h, hEvent, ev);
nsock++;
}
}
else
{
if (pfd[i].events & (POLLIN | POLLRDNORM |
POLLOUT | POLLWRNORM | POLLWRBAND))
handle_array[nhandles++] = h;
}
}
if (timeout == INFTIM)
wait_timeout = INFINITE;
else
wait_timeout = timeout;
for (;;)
{
ret = MsgWaitForMultipleObjects (nhandles, handle_array, FALSE,
wait_timeout, QS_ALLINPUT);
if (ret == WAIT_OBJECT_0 + nhandles)
{
/* new input of some other kind */
while ((bRet = PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)) != 0)
{
TranslateMessage (&msg);
DispatchMessage (&msg);
}
}
else
break;
}
/* Now check if the sockets have some event set. */
select (nsock + 1, rfds, wfds, efds, &tv0);
/* Place a sentinel at the end of the array. */
handle_array[nhandles] = NULL;
nhandles = 1;
for (i = 0; i < nfd; i++)
{
int happened;
if (pfd[i].fd < 0)
{
pfd[i].revents = 0;
continue;
}
h = (HANDLE) _get_osfhandle (i);
if (h != handle_array[nhandles])
{
/* It's a socket. */
WSAEventSelect (h, 0, 0);
happened = win32_compute_revents_socket ((SOCKET) h, pfd[i].events,
&rfds, &wfds, &efds);
}
else
{
/* Not a socket. */
nhandles++;
happened = win32_compute_revents (h, pfd[i].events);
}
if (happened)
{
pfd[i].revents = happened;
rc++;
}
}
return rc;
#endif
}
