Fix an architectural issue with the ORB that prevented publication from interrupt context.

ORB topic advertisements are now global handles that can be used in any context.  It is still possible to open a topic node as a publisher, but it's not the default.  As a consequence, the type of the handle returned from orb_advertise has changed; all other API remains the same.

apps/px4/attitude_estimator_bm/attitude_estimator_bm.c

@@ -154,7 +154,7 @@ int attitude_estimator_bm_main(int argc, char *argv[])
 	bool publishing = false;
 
 	/* advertise attitude */
-	int pub_att = orb_advertise(ORB_ID(vehicle_attitude), &att);
+	orb_advert_t pub_att = orb_advertise(ORB_ID(vehicle_attitude), &att);
 	publishing = true;
 
 	struct pollfd fds[] = {

apps/px4/fmu/fmu.cpp

@@ -89,7 +89,7 @@ private:
 	int		_task;
 	int		_t_actuators;
 	int		_t_armed;
-	int		_t_outputs;
+	orb_advert_t	_t_outputs;
 	unsigned	_num_outputs;
 
 	volatile bool	_task_should_exit;
@@ -566,15 +566,13 @@ fake(int argc, char *argv[])
 
 	ac.control[3] = strtol(argv[4], 0, 0) / 100.0f;
 
-	int handle = orb_advertise(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, &ac);
+	orb_advert_t handle = orb_advertise(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, &ac);
 
 	if (handle < 0) {
 		puts("advertise failed");
 		exit(1);
 	}
 
-	close(handle);
-
 	exit(0);
 }
 

apps/px4/px4io/driver/px4io.cpp

@@ -99,7 +99,7 @@ protected:
 	void			set_channels(unsigned count, const servo_position_t *data);
 
 private:
-	int			_publication;
+	orb_advert_t		_publication;
 	struct rc_input_values	_input;
 };