diff options
Diffstat (limited to 'src/backend/port/win32/socket.c')
| -rw-r--r-- | src/backend/port/win32/socket.c | 28 |
1 files changed, 12 insertions, 16 deletions
diff --git a/src/backend/port/win32/socket.c b/src/backend/port/win32/socket.c index 5d8fb7fc91d..6cc3ebd9824 100644 --- a/src/backend/port/win32/socket.c +++ b/src/backend/port/win32/socket.c @@ -523,11 +523,16 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c FD_ZERO(&outwritefds); /* - * Write FDs are different in the way that it is only flagged by - * WSASelectEvent() if we have tried to write to them first. So try an - * empty write + * Windows does not guarantee to log an FD_WRITE network event indicating + * that more data can be sent unless the previous send() failed with + * WSAEWOULDBLOCK. While our caller might well have made such a call, we + * cannot assume that here. Therefore, if waiting for write-ready, force + * the issue by doing a dummy send(). If the dummy send() succeeds, + * assume that the socket is in fact write-ready, and return immediately. + * Also, if it fails with something other than WSAEWOULDBLOCK, return a + * write-ready indication to let our caller deal with the error condition. */ - if (writefds) + if (writefds != NULL) { for (i = 0; i < writefds->fd_count; i++) { @@ -539,20 +544,11 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c buf.len = 0; r = WSASend(writefds->fd_array[i], &buf, 1, &sent, 0, NULL, NULL); - if (r == 0) /* Completed - means things are fine! */ + if (r == 0 || WSAGetLastError() != WSAEWOULDBLOCK) FD_SET(writefds->fd_array[i], &outwritefds); - - else - { /* Not completed */ - if (WSAGetLastError() != WSAEWOULDBLOCK) - - /* - * Not completed, and not just "would block", so an error - * occurred - */ - FD_SET(writefds->fd_array[i], &outwritefds); - } } + + /* If we found any write-ready sockets, just return them immediately */ if (outwritefds.fd_count > 0) { memcpy(writefds, &outwritefds, sizeof(fd_set)); |