ws: LCCSCF_PRIORITIZE_READS

include/libwebsockets/lws-client.h

@@ -61,6 +61,17 @@ enum lws_client_connect_ssl_connection_flags {
 	LCCSCF_H2_PRIOR_KNOWLEDGE		= (1 << 18),
 	LCCSCF_WAKE_SUSPEND__VALIDITY		= (1 << 19),
 	/* our validity checks are important enough to wake from suspend */
+	LCCSCF_PRIORITIZE_READS			= (1 << 20),
+	/**<
+	 * Normally lws balances reads and writes on all connections, so both
+	 * are possible even on busy connections, and we go around the event
+	 * loop more often to facilitate that, even if there is pending data.
+	 *
+	 * This flag indicates that you want to handle any pending reads on this
+	 * connection without yielding the service loop for anything else.  This
+	 * means you may block other connection processing in favour of incoming
+	 * data processing on this one if it receives back to back incoming rx.
+	 */
 };
 
 /** struct lws_client_connect_info - parameters to connect with when using

lib/roles/ws/ops-ws.c

@@ -1209,6 +1209,13 @@ drain:
 	}
 
 	pending = lws_ssl_pending(wsi);
+
+#if defined(LWS_WITH_CLIENT)
+	if (!pending && (wsi->flags & LCCSCF_PRIORITIZE_READS) &&
+	    lws_buflist_total_len(&wsi->buflist))
+		pending = 9999999;
+#endif
+
 	if (pending) {
 		if (lws_is_ws_with_ext(wsi))
 			pending = pending > wsi->ws->rx_ubuf_alloc ?