windows: proposed fix for CANCELLED

https://github.com/warmcat/libwebsockets/issues/1291

lib/plat/windows/windows-service.c

@@ -92,7 +92,10 @@ _lws_plat_service_tsi(struct lws_context *context, int timeout_ms, int tsi)
 		if (n < 0)
 			return -1;
 
-		/* Force WSAWaitForMultipleEvents() to check events and then return immediately. */
+		/*
+		 * Force WSAWaitForMultipleEvents() to check events
+		 * and then return immediately.
+		 */
 		timeout_ms = 0;
 
 		/* if something closed, retry this slot */
@@ -124,12 +127,21 @@ _lws_plat_service_tsi(struct lws_context *context, int timeout_ms, int tsi)
 		lws_pt_unlock(pt);
 	}
 
+	{
+		unsigned int eIdx;
+
+		for (eIdx = 0; eIdx < pt->fds_count; ++eIdx)
+			WSAEventSelect(pt->fds[eIdx].fd, pt->events,
+			       FD_READ | FD_WRITE | FD_OOB | FD_ACCEPT |
+			       FD_CONNECT | FD_CLOSE | FD_QOS |
+			       FD_ROUTING_INTERFACE_CHANGE |
+			       FD_ADDRESS_LIST_CHANGE);
+	}
+
 	ev = WSAWaitForMultipleEvents(1, &pt->events, FALSE, timeout_ms, FALSE);
 	if (ev == WSA_WAIT_EVENT_0) {
 		unsigned int eIdx;
 
-		WSAResetEvent(pt->events);
-
 		if (pt->context->tls_ops &&
 		    pt->context->tls_ops->fake_POLLIN_for_buffered)
 			pt->context->tls_ops->fake_POLLIN_for_buffered(pt);
@@ -137,13 +149,16 @@ _lws_plat_service_tsi(struct lws_context *context, int timeout_ms, int tsi)
 		for (eIdx = 0; eIdx < pt->fds_count; ++eIdx) {
 			unsigned int err;
 
-			if (WSAEnumNetworkEvents(pt->fds[eIdx].fd, 0,
+			if (WSAEnumNetworkEvents(pt->fds[eIdx].fd, pt->events,
 					&networkevents) == SOCKET_ERROR) {
 				lwsl_err("WSAEnumNetworkEvents() failed "
 					 "with error %d\n", LWS_ERRNO);
 				return -1;
 			}
 
+			if (!networkevents.lNetworkEvents)
+				networkevents.lNetworkEvents = LWS_POLLOUT;
+
 			pfd = &pt->fds[eIdx];
 			pfd->revents = (short)networkevents.lNetworkEvents;
 
@@ -171,10 +186,10 @@ _lws_plat_service_tsi(struct lws_context *context, int timeout_ms, int tsi)
 				lws_service_fd_tsi(context, pfd, tsi);
 			}
 		}
-	}
-
-	if (ev == WSA_WAIT_TIMEOUT)
+	} else if (ev == WSA_WAIT_TIMEOUT) {
 		lws_service_fd(context, NULL);
+	} else if (ev == WSA_WAIT_FAILED)
+		return 0;
 
 	return 0;
 }