fix-wait-for-writable-socket-on-windows.patch

diff --git a/src/backend/storage/ipc/latch.c b/src/backend/storage/ipc/latch.c
index ea7f930..300b866 100644
--- a/src/backend/storage/ipc/latch.c
+++ b/src/backend/storage/ipc/latch.c
@@ -1401,6 +1401,37 @@ WaitEventSetWaitBlock(WaitEventSet *set, int cur_timeout,
 			WaitEventAdjustWin32(set, cur_event);
 			cur_event->reset = false;
 		}
+
+		if (cur_event->events & WL_SOCKET_WRITEABLE)
+		{
+			char		c;
+			WSABUF		buf;
+			DWORD		sent;
+			int			r;
+
+			buf.buf = &c;
+			buf.len = 0;
+
+			r = WSASend(cur_event->fd, &buf, 1, &sent, 0, NULL, NULL);
+			if (r == 0)
+			{
+				occurred_events->pos = cur_event->pos;
+				occurred_events->user_data = cur_event->user_data;
+				occurred_events->events = WL_SOCKET_WRITEABLE;
+				occurred_events->fd = cur_event->fd;
+				return 1;
+			}
+			else
+			{
+				if (WSAGetLastError() != WSAEWOULDBLOCK)
+					/*
+					 * Not completed, and not just "would block", so an error
+					 * occurred
+					 */
+					elog(ERROR, "failed writability check on socket: error code %u",
+						 WSAGetLastError());
+			}
+		}
 	}
 
 	/*