Implement asynchronous name resolution

* process.c (Fmake_network_process): Do asynchronous DNS
lookups if we have getaddrinfo_a and the user requests :nowait.
(check_for_dns): New function.
(wait_reading_process_output): Check for pending name
resolution in the idle loop.

* process.h: Add structure for async DNS.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/process.h b/src/process.h
index e2e6ca92984..684434c1748 100644
--- a/src/process.h
+++ b/src/process.h
@@ -161,14 +161,26 @@ struct Lisp_Process
        flag indicates that `raw_status' contains a new status that still
        needs to be synced to `status'.  */
     bool_bf raw_status_new : 1;
+    /* Whether this is a nonblocking socket. */
     bool_bf is_non_blocking_client : 1;
+    /* Whether this is a server or a client socket. */
     bool_bf is_server : 1;
     int raw_status;
+    /* The length of the socket backlog. */
     int backlog;
+    /* The port number. */
     int port;
+    /* The socket type. */
     int socktype;
+    /* The socket protocol. */
     int ai_protocol;
 
+#ifdef HAVE_GETADDRINFO_A
+    /* Whether the socket is waiting for response from an asynchronous
+       DNS call. */
+    struct gaicb* dns_request;
+#endif
+
 #ifdef HAVE_GNUTLS
     gnutls_initstage_t gnutls_initstage;
     gnutls_session_t gnutls_state;