+#ifdef TCP_QUICKACK /* Avoid pure-ACKs while in tls protocol pingpong phase */
+ /* Unfortunately we cannot be certain to do this before a TLS-on-connect
+ Client Hello arrives and is acked. We do it as early as possible. */
+ (void) setsockopt(accept_socket, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
+#endif