diff options
| -rw-r--r-- | ares/ares_fds.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/ares/ares_fds.c b/ares/ares_fds.c index e8d2ee28b..a305b3b28 100644 --- a/ares/ares_fds.c +++ b/ares/ares_fds.c @@ -30,20 +30,23 @@ int ares_fds(ares_channel channel, fd_set *read_fds, fd_set *write_fds) ares_socket_t nfds; int i; - /* No queries, no file descriptors. */ - if (!channel->queries) - return 0; - nfds = 0; for (i = 0; i < channel->nservers; i++) { server = &channel->servers[i]; - if (server->udp_socket != ARES_SOCKET_BAD) + /* We only need to register interest in UDP sockets if we have + * outstanding queries. + */ + if (channel->queries && server->udp_socket != ARES_SOCKET_BAD) { FD_SET(server->udp_socket, read_fds); if (server->udp_socket >= nfds) nfds = server->udp_socket + 1; } + /* We always register for TCP events, because we want to know + * when the other side closes the connection, so we don't waste + * time trying to use a broken connection. + */ if (server->tcp_socket != ARES_SOCKET_BAD) { FD_SET(server->tcp_socket, read_fds); |