const the listener array, saves a little RAM.

apps/mavlink/orb_listener.c

@@ -91,32 +91,32 @@ static uint64_t last_sensor_timestamp;
 static void	*uorb_receive_thread(void *arg);
 
 struct listener {
-	void	(*callback)(struct listener *l);
+	void	(*callback)(const struct listener *l);
 	int		*subp;
 	uintptr_t	arg;
 };
 
-static void	l_sensor_combined(struct listener *l);
-static void	l_vehicle_attitude(struct listener *l);
-static void	l_vehicle_gps_position(struct listener *l);
-static void	l_vehicle_status(struct listener *l);
-static void	l_rc_channels(struct listener *l);
-static void	l_input_rc(struct listener *l);
-static void	l_global_position(struct listener *l);
-static void	l_local_position(struct listener *l);
-static void	l_global_position_setpoint(struct listener *l);
-static void	l_local_position_setpoint(struct listener *l);
-static void	l_attitude_setpoint(struct listener *l);
-static void	l_actuator_outputs(struct listener *l);
-static void	l_actuator_armed(struct listener *l);
-static void	l_manual_control_setpoint(struct listener *l);
-static void	l_vehicle_attitude_controls(struct listener *l);
-static void	l_debug_key_value(struct listener *l);
-static void	l_optical_flow(struct listener *l);
-static void	l_vehicle_rates_setpoint(struct listener *l);
-static void	l_home(struct listener *l);
-
-struct listener listeners[] = {
+static void	l_sensor_combined(const struct listener *l);
+static void	l_vehicle_attitude(const struct listener *l);
+static void	l_vehicle_gps_position(const struct listener *l);
+static void	l_vehicle_status(const struct listener *l);
+static void	l_rc_channels(const struct listener *l);
+static void	l_input_rc(const struct listener *l);
+static void	l_global_position(const struct listener *l);
+static void	l_local_position(const struct listener *l);
+static void	l_global_position_setpoint(const struct listener *l);
+static void	l_local_position_setpoint(const struct listener *l);
+static void	l_attitude_setpoint(const struct listener *l);
+static void	l_actuator_outputs(const struct listener *l);
+static void	l_actuator_armed(const struct listener *l);
+static void	l_manual_control_setpoint(const struct listener *l);
+static void	l_vehicle_attitude_controls(const struct listener *l);
+static void	l_debug_key_value(const struct listener *l);
+static void	l_optical_flow(const struct listener *l);
+static void	l_vehicle_rates_setpoint(const struct listener *l);
+static void	l_home(const struct listener *l);
+
+static const struct listener listeners[] = {
 	{l_sensor_combined,		&mavlink_subs.sensor_sub,	0},
 	{l_vehicle_attitude,		&mavlink_subs.att_sub,		0},
 	{l_vehicle_gps_position,	&mavlink_subs.gps_sub,		0},
@@ -144,7 +144,7 @@ struct listener listeners[] = {
 static const unsigned n_listeners = sizeof(listeners) / sizeof(listeners[0]);
 
 void
-l_sensor_combined(struct listener *l)
+l_sensor_combined(const struct listener *l)
 {
 	struct sensor_combined_s raw;
 
@@ -199,7 +199,7 @@ l_sensor_combined(struct listener *l)
 }
 
 void
-l_vehicle_attitude(struct listener *l)
+l_vehicle_attitude(const struct listener *l)
 {
 	struct vehicle_attitude_s att;
 
@@ -222,7 +222,7 @@ l_vehicle_attitude(struct listener *l)
 }
 
 void
-l_vehicle_gps_position(struct listener *l)
+l_vehicle_gps_position(const struct listener *l)
 {
 	struct vehicle_gps_position_s gps;
 
@@ -256,7 +256,7 @@ l_vehicle_gps_position(struct listener *l)
 }
 
 void
-l_vehicle_status(struct listener *l)
+l_vehicle_status(const struct listener *l)
 {
 	/* immediately communicate state changes back to user */
 	orb_copy(ORB_ID(vehicle_status), status_sub, &v_status);
@@ -280,7 +280,7 @@ l_vehicle_status(struct listener *l)
 }
 
 void
-l_rc_channels(struct listener *l)
+l_rc_channels(const struct listener *l)
 {
 	/* copy rc channels into local buffer */
 	orb_copy(ORB_ID(rc_channels), rc_sub, &rc);
@@ -288,7 +288,7 @@ l_rc_channels(struct listener *l)
 }
 
 void
-l_input_rc(struct listener *l)
+l_input_rc(const struct listener *l)
 {
 	/* copy rc channels into local buffer */
 	orb_copy(ORB_ID(input_rc), mavlink_subs.input_rc_sub, &rc_raw);
@@ -310,7 +310,7 @@ l_input_rc(struct listener *l)
 }
 
 void
-l_global_position(struct listener *l)
+l_global_position(const struct listener *l)
 {
 	/* copy global position data into local buffer */
 	orb_copy(ORB_ID(vehicle_global_position), mavlink_subs.global_pos_sub, &global_pos);
@@ -340,7 +340,7 @@ l_global_position(struct listener *l)
 }
 
 void
-l_local_position(struct listener *l)
+l_local_position(const struct listener *l)
 {
 	/* copy local position data into local buffer */
 	orb_copy(ORB_ID(vehicle_local_position), mavlink_subs.local_pos_sub, &local_pos);
@@ -357,7 +357,7 @@ l_local_position(struct listener *l)
 }
 
 void
-l_global_position_setpoint(struct listener *l)
+l_global_position_setpoint(const struct listener *l)
 {
 	struct vehicle_global_position_setpoint_s global_sp;
 
@@ -379,7 +379,7 @@ l_global_position_setpoint(struct listener *l)
 }
 
 void
-l_local_position_setpoint(struct listener *l)
+l_local_position_setpoint(const struct listener *l)
 {
 	struct vehicle_local_position_setpoint_s local_sp;
 
@@ -396,7 +396,7 @@ l_local_position_setpoint(struct listener *l)
 }
 
 void
-l_attitude_setpoint(struct listener *l)
+l_attitude_setpoint(const struct listener *l)
 {
 	struct vehicle_attitude_setpoint_s att_sp;
 
@@ -413,7 +413,7 @@ l_attitude_setpoint(struct listener *l)
 }
 
 void
-l_vehicle_rates_setpoint(struct listener *l)
+l_vehicle_rates_setpoint(const struct listener *l)
 {
 	struct vehicle_rates_setpoint_s rates_sp;
 
@@ -430,7 +430,7 @@ l_vehicle_rates_setpoint(struct listener *l)
 }
 
 void
-l_actuator_outputs(struct listener *l)
+l_actuator_outputs(const struct listener *l)
 {
 	struct actuator_outputs_s act_outputs;
 
@@ -529,13 +529,13 @@ l_actuator_outputs(struct listener *l)
 }
 
 void
-l_actuator_armed(struct listener *l)
+l_actuator_armed(const struct listener *l)
 {
 	orb_copy(ORB_ID(actuator_armed), mavlink_subs.armed_sub, &armed);
 }
 
 void
-l_manual_control_setpoint(struct listener *l)
+l_manual_control_setpoint(const struct listener *l)
 {
 	struct manual_control_setpoint_s man_control;
 
@@ -553,7 +553,7 @@ l_manual_control_setpoint(struct listener *l)
 }
 
 void
-l_vehicle_attitude_controls(struct listener *l)
+l_vehicle_attitude_controls(const struct listener *l)
 {
 	struct actuator_controls_effective_s actuators;
 
@@ -581,7 +581,7 @@ l_vehicle_attitude_controls(struct listener *l)
 }
 
 void
-l_debug_key_value(struct listener *l)
+l_debug_key_value(const struct listener *l)
 {
 	struct debug_key_value_s debug;
 
@@ -597,7 +597,7 @@ l_debug_key_value(struct listener *l)
 }
 
 void
-l_optical_flow(struct listener *l)
+l_optical_flow(const struct listener *l)
 {
 	struct optical_flow_s flow;
 
@@ -608,7 +608,7 @@ l_optical_flow(struct listener *l)
 }
 
 void
-l_home(struct listener *l)
+l_home(const struct listener *l)
 {
 	struct home_position_s home;