Send more packets together with nice_agent_send_messages_nonblocking

conf/janus.jcfg.sample.in

@@ -105,6 +105,13 @@ general: {
 									# As such, if you want to use this you should
 									# provision the correct value according to the
 									# available resources (e.g., CPUs available).
+	#disable_sendmmsg = true		# By default, Janus tries to take advantage of
+									# sendmmsg to send multiple packets at the same
+									# time and optimize media delivery, by reducing
+									# the number of system calls. If you want to
+									# disable this behaviour and make it work more
+									# like Janus did previously, by sending one
+									# packet at the time, uncomment this property.
 	#allow_loop_indication = true	# In case a static number of event loops is
 									# configured as explained above, by default
 									# new handles will be allocated on one loop or

ice.c

@@ -147,6 +147,17 @@ gboolean janus_is_opaqueid_in_api_enabled(void) {
 	return opaqueid_in_api;
 }
 
+/* Since #2295, we support sendmmsg to send multiple packets at the same time
+ * and optimize media delivery; this can disabled at startup, if needed */
+static gboolean use_sendmmsg = TRUE;
+void janus_disable_sendmmsg(void) {
+	JANUS_LOG(LOG_WARN, "Disabling sendmmsg mode, will send one packet at a time\n");
+	use_sendmmsg = FALSE;
+}
+gboolean janus_is_sendmmsg_enabled(void) {
+	return use_sendmmsg;
+}
+
 /* Only needed in case we're using static event loops spawned at startup (disabled by default) */
 typedef struct janus_ice_static_event_loop {
 	int id;
@@ -5118,6 +5129,15 @@ static gboolean janus_ice_send_or_store(janus_ice_handle *handle,
 		janus_ice_component *component, janus_ice_queued_packet *pkt) {
 	if(!handle || !component || !pkt)
 		return FALSE;
+	if(!use_sendmmsg) {
+		/* We're not using sendmmsg, use nice_agent_send right away */
+		int sent = nice_agent_send(handle->agent, component->stream_id,
+			component->component_id, pkt->length, (const gchar *)pkt->data);
+		if(sent < pkt->length) {
+			JANUS_LOG(LOG_ERR, "[%"SCNu64"] ... only sent %d bytes? (was %d)\n", handle->handle_id, sent, pkt->length);
+		}
+		return sent == pkt->length;
+	}
 	/* First of all, let's set this packet in the first available NiceOutputMessage */
 	if(component->pending_messages_num == JANUS_MAX_PENDING_MESSAGES) {
 		JANUS_LOG(LOG_WARN, "[%"SCNu64"] Too many packets pending? Dumping this packet...\n", handle->handle_id);

ice.h

@@ -206,6 +206,11 @@ void janus_enable_opaqueid_in_api(void);
 /*! \brief Method to check whether opaque ID have to be added to Janus API responses/events
  * @returns TRUE if they need to be present, FALSE otherwise */
 gboolean janus_is_opaqueid_in_api_enabled(void);
+/*! \brief Method to disable the new sendmmsg mode */
+void janus_disable_sendmmsg(void);
+/*! \brief Method to check whether the sendmmsg mode is enabled
+ * @returns TRUE if it's enabled (default), FALSE otherwise */
+gboolean janus_is_sendmmsg_enabled(void);
 
 
 /*! \brief Helper method to get a string representation of a libnice ICE state

janus.c

@@ -373,6 +373,8 @@ static json_t *janus_info(const char *transaction) {
 		json_object_set_new(info, "turn-server", json_string(server));
 	}
 	json_object_set_new(info, "static-event-loops", json_integer(janus_ice_get_static_event_loops()));
+	if(!janus_is_sendmmsg_enabled())
+		json_object_set_new(info, "sendmmsg-enabled", json_false());
 	json_object_set_new(info, "api_secret", api_secret ? json_true() : json_false());
 	json_object_set_new(info, "auth_token", janus_auth_is_enabled() ? json_true() : json_false());
 	json_object_set_new(info, "event_handlers", janus_events_is_enabled() ? json_true() : json_false());
@@ -4835,6 +4837,10 @@ gint main(int argc, char *argv[])
 			loops_api = janus_is_true(item->value);
 		janus_ice_set_static_event_loops(loops, loops_api);
 	}
+	/* Also check if we need to disable the new sendmmsg mode */
+	item = janus_config_get(config, config_general, janus_config_type_item, "disable_sendmmsg");
+	if(item && item->value && janus_is_true(item->value))
+		janus_disable_sendmmsg();
 	/* Initialize the ICE stack now */
 	janus_ice_init(ice_lite, ice_tcp, full_trickle, ignore_mdns, ipv6, rtp_min_port, rtp_max_port);
 	if(janus_ice_set_stun_server(stun_server, stun_port) < 0) {