Hi,
I ran into the same problem a couple of days ago. I modified the
implementation of apr_poll_revents_get() to the attached file, to fix the
problem. Basically, if the socket is listening, then the WSARecv isn't done.
Also I added another fix where if the WSARecv returns zero bytes on a
stream-type socket, that indicates a graceful shutdown (APR_POLLHUP instead
of APR_POLLIN).
I can create a proper diff-style patch for this if people agree it's
sensible?
cya,
Saxon
----- Original Message -----
From: "INOUE Seiichiro" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, March 25, 2002 12:32 AM
Subject: [Q] apr_poll_revents_get() before apr_accept() on Windows
> Hi,
>
> I have a question about apr_poll_revents_get() behavior on Windows.
> I want to check whether the socket is apr_accept()'able.
> On Unix, I can check the socket becomes readable by apr_poll().
> On Windows, when I do the same thing, apr_poll_revents_get() returns
APR_POLLERR.
>
> In apr_poll_revents_get(), WSARecv() causes WSAENOTCONN,
> if the socket hasn't been apr_accept()'ed yet.
> (Windows2000 case. I don't know other Windows.)
>
> I attach a sample program for an easy reproduction.
>
> My question is,
> What is a proper solution?
> libapr should take care of it, or applications should?
>
> Thanks in advance.
>
> - INOUE Seiichiro <[EMAIL PROTECTED]>
> http://www.ariel-networks.com
APR_DECLARE(apr_status_t) apr_poll_revents_get(apr_int16_t *event,
apr_socket_t *sock,
apr_pollfd_t *aprset)
{
apr_int16_t revents = 0;
WSABUF data;
char buf[256];
DWORD dummy;
DWORD flags = MSG_PEEK;
BOOL optval;
int optlen;
/* We just want to PEEK at the data, so I am setting up a dummy WSABUF
* variable here.
*/
data.len = sizeof(buf);
data.buf = buf;
if (FD_ISSET(sock->sock, aprset->read)) {
revents |= APR_POLLIN;
/* Check if the socket is listening for a connection (SO_ACCEPTCONN
* is true) - if it is we just leave APR_POLLIN in revents and
* don't attempt the WSARecv, since it would return WSAENOTCONN.
*/
optlen = sizeof(optval);
getsockopt(sock->sock, SOL_SOCKET, SO_ACCEPTCONN, (char *)&optval,
&optlen);
if (!optval) {
/* The socket is not listening */
if (WSARecv(sock->sock, &data, 1, &dummy, &flags, NULL,
NULL) == SOCKET_ERROR) {
/* This is only legit since we don't return the error */
dummy = WSAGetLastError();
switch (dummy) {
case WSAECONNRESET:
case WSAECONNABORTED:
case WSAESHUTDOWN:
case WSAENETRESET: {
revents ^= APR_POLLIN;
revents |= APR_POLLHUP;
break;
}
case WSAENOTSOCK: {
revents ^= APR_POLLIN;
revents |= APR_POLLNVAL;
}
default: {
revents ^= APR_POLLIN;
revents |= APR_POLLERR;
}
}
}
else if ((dummy == 0) && (sock->type == SOCK_STREAM)) {
/* Zero bytes received (dummy is the number of bytes)
* from a stream socket indicates graceful shutdown.
*/
revents ^= APR_POLLIN;
revents |= APR_POLLHUP;
}
}
}
if (FD_ISSET(sock->sock, aprset->write)) {
revents |= APR_POLLOUT;
}
/* I am assuming that the except is for out of band data, not a failed
* connection on a non-blocking socket. Might be a bad assumption, but
* it works for now. rbb.
*/
if (FD_ISSET(sock->sock, aprset->except)) {
revents |= APR_POLLPRI;
}
(*event) = revents;
return APR_SUCCESS;
}
