1 /*-------------------------------------------------------------------------
4 * Microsoft Windows Win32 Socket Functions
6 * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
9 * $PostgreSQL: pgsql/src/backend/port/win32/socket.c,v 1.22 2009/06/11 14:49:00 momjian Exp $
11 *-------------------------------------------------------------------------
24 * Blocking socket functions implemented so they listen on both
25 * the socket and the signal event, required for signal handling.
29 * Convert the last socket error code into errno
32 TranslateSocketError(void)
34 switch (WSAGetLastError())
36 case WSANOTINITIALISED:
40 case WSAESOCKTNOSUPPORT:
42 case WSAEINVALIDPROVIDER:
43 case WSAEINVALIDPROCTABLE:
56 case WSAEPROTONOSUPPORT:
58 errno = EPROTONOSUPPORT;
84 errno = ECONNREFUSED; /* ENOTCONN? */
88 (errmsg_internal("Unknown win32 socket error code: %i", WSAGetLastError())));
94 pgwin32_poll_signals(void)
96 if (UNBLOCKED_SIGNAL_QUEUE())
98 pgwin32_dispatch_queued_signals();
109 int typelen = sizeof(type);
111 if (getsockopt(s, SOL_SOCKET, SO_TYPE, (char *) &type, &typelen))
114 return (type == SOCK_DGRAM) ? 1 : 0;
118 pgwin32_waitforsinglesocket(SOCKET s, int what, int timeout)
120 static HANDLE waitevent = INVALID_HANDLE_VALUE;
121 static SOCKET current_socket = -1;
122 static int isUDP = 0;
126 if (waitevent == INVALID_HANDLE_VALUE)
128 waitevent = CreateEvent(NULL, TRUE, FALSE, NULL);
130 if (waitevent == INVALID_HANDLE_VALUE)
132 (errmsg_internal("Failed to create socket waiting event: %i", (int) GetLastError())));
134 else if (!ResetEvent(waitevent))
136 (errmsg_internal("Failed to reset socket waiting event: %i", (int) GetLastError())));
139 * make sure we don't multiplex this kernel event object with a different
140 * socket from a previous call
143 if (current_socket != s)
145 if (current_socket != -1)
146 WSAEventSelect(current_socket, waitevent, 0);
147 isUDP = isDataGram(s);
152 if (WSAEventSelect(s, waitevent, what) == SOCKET_ERROR)
154 TranslateSocketError();
158 events[0] = pgwin32_signal_event;
159 events[1] = waitevent;
162 * Just a workaround of unknown locking problem with writing in UDP socket
163 * under high load: Client's pgsql backend sleeps infinitely in
164 * WaitForMultipleObjectsEx, pgstat process sleeps in pgwin32_select().
165 * So, we will wait with small timeout(0.1 sec) and if sockect is still
166 * blocked, try WSASend (see comments in pgwin32_select) and wait again.
168 if ((what & FD_WRITE) && isUDP)
172 r = WaitForMultipleObjectsEx(2, events, FALSE, 100, TRUE);
174 if (r == WAIT_TIMEOUT)
183 r = WSASend(s, &buf, 1, &sent, 0, NULL, NULL);
184 if (r == 0) /* Completed - means things are fine! */
186 else if (WSAGetLastError() != WSAEWOULDBLOCK)
188 TranslateSocketError();
197 r = WaitForMultipleObjectsEx(2, events, FALSE, timeout, TRUE);
199 if (r == WAIT_OBJECT_0 || r == WAIT_IO_COMPLETION)
201 pgwin32_dispatch_queued_signals();
205 if (r == WAIT_OBJECT_0 + 1)
207 if (r == WAIT_TIMEOUT)
210 (errmsg_internal("Bad return from WaitForMultipleObjects: %i (%i)", r, (int) GetLastError())));
215 * Create a socket, setting it to overlapped and non-blocking
218 pgwin32_socket(int af, int type, int protocol)
221 unsigned long on = 1;
223 s = WSASocket(af, type, protocol, NULL, 0, WSA_FLAG_OVERLAPPED);
224 if (s == INVALID_SOCKET)
226 TranslateSocketError();
227 return INVALID_SOCKET;
230 if (ioctlsocket(s, FIONBIO, &on))
232 TranslateSocketError();
233 return INVALID_SOCKET;
242 pgwin32_accept(SOCKET s, struct sockaddr * addr, int *addrlen)
247 * Poll for signals, but don't return with EINTR, since we don't handle
250 pgwin32_poll_signals();
252 rs = WSAAccept(s, addr, addrlen, NULL, 0);
253 if (rs == INVALID_SOCKET)
255 TranslateSocketError();
256 return INVALID_SOCKET;
262 /* No signal delivery during connect. */
264 pgwin32_connect(SOCKET s, const struct sockaddr * addr, int addrlen)
268 r = WSAConnect(s, addr, addrlen, NULL, NULL, NULL, NULL);
272 if (WSAGetLastError() != WSAEWOULDBLOCK)
274 TranslateSocketError();
278 while (pgwin32_waitforsinglesocket(s, FD_CONNECT, INFINITE) == 0)
280 /* Loop endlessly as long as we are just delivering signals */
287 pgwin32_recv(SOCKET s, char *buf, int len, int f)
295 if (pgwin32_poll_signals())
301 r = WSARecv(s, &wbuf, 1, &b, &flags, NULL, NULL);
302 if (r != SOCKET_ERROR && b > 0)
303 /* Read succeeded right away */
306 if (r == SOCKET_ERROR &&
307 WSAGetLastError() != WSAEWOULDBLOCK)
309 TranslateSocketError();
313 /* No error, zero bytes (win2000+) or error+WSAEWOULDBLOCK (<=nt4) */
315 for (n = 0; n < 5; n++)
317 if (pgwin32_waitforsinglesocket(s, FD_READ | FD_CLOSE | FD_ACCEPT,
319 return -1; /* errno already set */
321 r = WSARecv(s, &wbuf, 1, &b, &flags, NULL, NULL);
322 if (r == SOCKET_ERROR)
324 if (WSAGetLastError() == WSAEWOULDBLOCK)
327 * There seem to be cases on win2k (at least) where WSARecv
328 * can return WSAEWOULDBLOCK even when
329 * pgwin32_waitforsinglesocket claims the socket is readable.
330 * In this case, just sleep for a moment and try again. We try
331 * up to 5 times - if it fails more than that it's not likely
337 TranslateSocketError();
343 (errmsg_internal("Failed to read from ready socket (after retries)")));
349 pgwin32_send(SOCKET s, char *buf, int len, int flags)
355 if (pgwin32_poll_signals())
362 * Readiness of socket to send data to UDP socket may be not true: socket
363 * can become busy again! So loop until send or error occurs.
367 r = WSASend(s, &wbuf, 1, &b, flags, NULL, NULL);
368 if (r != SOCKET_ERROR && b > 0)
369 /* Write succeeded right away */
372 if (r == SOCKET_ERROR &&
373 WSAGetLastError() != WSAEWOULDBLOCK)
375 TranslateSocketError();
379 /* No error, zero bytes (win2000+) or error+WSAEWOULDBLOCK (<=nt4) */
381 if (pgwin32_waitforsinglesocket(s, FD_WRITE | FD_CLOSE, INFINITE) == 0)
390 * Wait for activity on one or more sockets.
391 * While waiting, allow signals to run
393 * NOTE! Currently does not implement exceptfds check,
394 * since it is not used in postgresql!
397 pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, const struct timeval * timeout)
399 WSAEVENT events[FD_SETSIZE * 2]; /* worst case is readfds totally
400 * different from writefds, so
401 * 2*FD_SETSIZE sockets */
402 SOCKET sockets[FD_SETSIZE * 2];
406 DWORD timeoutval = WSA_INFINITE;
411 Assert(exceptfds == NULL);
413 if (pgwin32_poll_signals())
416 FD_ZERO(&outreadfds);
417 FD_ZERO(&outwritefds);
420 * Write FDs are different in the way that it is only flagged by
421 * WSASelectEvent() if we have tried to write to them first. So try an
426 for (i = 0; i < writefds->fd_count; i++)
435 r = WSASend(writefds->fd_array[i], &buf, 1, &sent, 0, NULL, NULL);
436 if (r == 0) /* Completed - means things are fine! */
437 FD_SET (writefds->fd_array[i], &outwritefds);
440 { /* Not completed */
441 if (WSAGetLastError() != WSAEWOULDBLOCK)
444 * Not completed, and not just "would block", so an error
447 FD_SET (writefds->fd_array[i], &outwritefds);
450 if (outwritefds.fd_count > 0)
452 memcpy(writefds, &outwritefds, sizeof(fd_set));
455 return outwritefds.fd_count;
460 /* Now set up for an actual select */
464 /* timeoutval is in milliseconds */
465 timeoutval = timeout->tv_sec * 1000 + timeout->tv_usec / 1000;
470 for (i = 0; i < readfds->fd_count; i++)
472 events[numevents] = WSACreateEvent();
473 sockets[numevents] = readfds->fd_array[i];
477 if (writefds != NULL)
479 for (i = 0; i < writefds->fd_count; i++)
482 !FD_ISSET(writefds->fd_array[i], readfds))
484 /* If the socket is not in the read list */
485 events[numevents] = WSACreateEvent();
486 sockets[numevents] = writefds->fd_array[i];
492 for (i = 0; i < numevents; i++)
496 if (readfds && FD_ISSET(sockets[i], readfds))
497 flags |= FD_READ | FD_ACCEPT | FD_CLOSE;
499 if (writefds && FD_ISSET(sockets[i], writefds))
500 flags |= FD_WRITE | FD_CLOSE;
502 if (WSAEventSelect(sockets[i], events[i], flags) == SOCKET_ERROR)
504 TranslateSocketError();
505 for (i = 0; i < numevents; i++)
506 WSACloseEvent(events[i]);
511 events[numevents] = pgwin32_signal_event;
512 r = WaitForMultipleObjectsEx(numevents + 1, events, FALSE, timeoutval, TRUE);
513 if (r != WAIT_TIMEOUT && r != WAIT_IO_COMPLETION && r != (WAIT_OBJECT_0 + numevents))
516 * We scan all events, even those not signalled, in case more than one
517 * event has been tagged but Wait.. can only return one.
519 WSANETWORKEVENTS resEvents;
521 for (i = 0; i < numevents; i++)
523 ZeroMemory(&resEvents, sizeof(resEvents));
524 if (WSAEnumNetworkEvents(sockets[i], events[i], &resEvents) == SOCKET_ERROR)
526 (errmsg_internal("failed to enumerate network events: %i", (int) GetLastError())));
528 if (readfds && FD_ISSET(sockets[i], readfds))
530 if ((resEvents.lNetworkEvents & FD_READ) ||
531 (resEvents.lNetworkEvents & FD_ACCEPT) ||
532 (resEvents.lNetworkEvents & FD_CLOSE))
534 FD_SET (sockets[i], &outreadfds);
539 /* Write activity? */
540 if (writefds && FD_ISSET(sockets[i], writefds))
542 if ((resEvents.lNetworkEvents & FD_WRITE) ||
543 (resEvents.lNetworkEvents & FD_CLOSE))
545 FD_SET (sockets[i], &outwritefds);
553 /* Clean up all handles */
554 for (i = 0; i < numevents; i++)
556 WSAEventSelect(sockets[i], events[i], 0);
557 WSACloseEvent(events[i]);
560 if (r == WSA_WAIT_TIMEOUT)
569 if (r == WAIT_OBJECT_0 + numevents)
571 pgwin32_dispatch_queued_signals();
580 /* Overwrite socket sets with our resulting values */
582 memcpy(readfds, &outreadfds, sizeof(fd_set));
584 memcpy(writefds, &outwritefds, sizeof(fd_set));
590 * Return win32 error string, since strerror can't
591 * handle winsock codes
593 static char wserrbuf[256];
595 pgwin32_socket_strerror(int err)
597 static HANDLE handleDLL = INVALID_HANDLE_VALUE;
599 if (handleDLL == INVALID_HANDLE_VALUE)
601 handleDLL = LoadLibraryEx("netmsg.dll", NULL, DONT_RESOLVE_DLL_REFERENCES | LOAD_LIBRARY_AS_DATAFILE);
602 if (handleDLL == NULL)
604 (errmsg_internal("Failed to load netmsg.dll: %i", (int) GetLastError())));
607 ZeroMemory(&wserrbuf, sizeof(wserrbuf));
608 if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_FROM_HMODULE,
611 MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
613 sizeof(wserrbuf) - 1,
616 /* Failed to get id */
617 sprintf(wserrbuf, "Unknown winsock error %i", err);