PX4-Autopilot/src/modules/uORB/uORB.h

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#ifndef _UORB_UORB_H
#define _UORB_UORB_H

/**
 * @file uORB.h
 * API for the uORB lightweight object broker.
 */

#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>

// Hack until everything is using this header
#include <systemlib/visibility.h>

/**
 * Object metadata.
 */
struct orb_metadata {
	const char *o_name;		/**< unique object name */
	const size_t o_size;		/**< object size */
};

typedef const struct orb_metadata *orb_id_t;

/**
 * Maximum number of multi topic instances
 */
#define ORB_MULTI_MAX_INSTANCES	4

/**
 * Topic priority.
 * Relevant for multi-topics / topic groups
 */
enum ORB_PRIO {
	ORB_PRIO_MIN = 0,
	ORB_PRIO_VERY_LOW = 25,
	ORB_PRIO_LOW = 50,
	ORB_PRIO_DEFAULT = 75,
	ORB_PRIO_HIGH = 100,
	ORB_PRIO_VERY_HIGH = 125,
	ORB_PRIO_MAX = 255
};

/**
 * Generates a pointer to the uORB metadata structure for
 * a given topic.
 *
 * The topic must have been declared previously in scope
 * with ORB_DECLARE().
 *
 * @param _name		The name of the topic.
 */
#define ORB_ID(_name)		&__orb_##_name

/**
 * Declare (prototype) the uORB metadata for a topic.
 *
 * @param _name		The name of the topic.
 */
#if defined(__cplusplus)
# define ORB_DECLARE(_name)		extern "C" const struct orb_metadata __orb_##_name __EXPORT
# define ORB_DECLARE_OPTIONAL(_name)	extern "C" const struct orb_metadata __orb_##_name __EXPORT
#else
# define ORB_DECLARE(_name)		extern const struct orb_metadata __orb_##_name __EXPORT
# define ORB_DECLARE_OPTIONAL(_name)	extern const struct orb_metadata __orb_##_name __EXPORT
#endif

/**
 * Define (instantiate) the uORB metadata for a topic.
 *
 * The uORB metadata is used to help ensure that updates and
 * copies are accessing the right data.
 *
 * Note that there must be no more than one instance of this macro
 * for each topic.
 *
 * @param _name		The name of the topic.
 * @param _struct	The structure the topic provides.
 */
#define ORB_DEFINE(_name, _struct)			\
	const struct orb_metadata __orb_##_name = {	\
		#_name,					\
		sizeof(_struct)				\
	}; struct hack

__BEGIN_DECLS

/**
 * ORB topic advertiser handle.
 *
 * Advertiser handles are global; once obtained they can be shared freely
 * and do not need to be closed or released.
 *
 * This permits publication from interrupt context and other contexts where
 * a file-descriptor-based handle would not otherwise be in scope for the
 * publisher.
 */
typedef void 	*orb_advert_t;

/**
 * @see uORB::Manager::orb_advertise()
 */
extern orb_advert_t orb_advertise(const struct orb_metadata *meta, const void *data) __EXPORT;

/**
 * @see uORB::Manager::orb_advertise_multi()
 */
extern orb_advert_t orb_advertise_multi(const struct orb_metadata *meta, const void *data, int *instance,
					int priority) __EXPORT;

/**
 * Advertise as the publisher of a topic.
 *
 * This performs the initial advertisement of a topic; it creates the topic
 * node in /obj if required and publishes the initial data.
 *
 * @see uORB::Manager::orb_advertise_multi() for meaning of the individual parameters
 */
extern int orb_publish_auto(const struct orb_metadata *meta, orb_advert_t *handle, const void *data, int *instance,
			    int priority);

/**
 * @see uORB::Manager::orb_publish()
 */
extern int	orb_publish(const struct orb_metadata *meta, orb_advert_t handle, const void *data) __EXPORT;

/**
 * @see uORB::Manager::orb_subscribe()
 */
extern int	orb_subscribe(const struct orb_metadata *meta) __EXPORT;

/**
 * @see uORB::Manager::orb_subscribe_multi()
 */
extern int	orb_subscribe_multi(const struct orb_metadata *meta, unsigned instance) __EXPORT;

/**
 * @see uORB::Manager::orb_unsubscribe()
 */
extern int	orb_unsubscribe(int handle) __EXPORT;

/**
 * @see uORB::Manager::orb_copy()
 */
extern int	orb_copy(const struct orb_metadata *meta, int handle, void *buffer) __EXPORT;

/**
 * @see uORB::Manager::orb_advertise()
 */
extern int	orb_check(int handle, bool *updated) __EXPORT;

/**
 * @see uORB::Manager::orb_stat()
 */
extern int	orb_stat(int handle, uint64_t *time) __EXPORT;

/**
 * @see uORB::Manager::orb_exists()
 */
extern int	orb_exists(const struct orb_metadata *meta, int instance) __EXPORT;

/**
 * Get the number of published instances of a topic group
 *
 * @param meta    ORB topic metadata.
 * @return    The number of published instances of this topic
 */
extern int	orb_group_count(const struct orb_metadata *meta) __EXPORT;

/**
 * @see uORB::Manager::orb_priority()
 */
extern int	orb_priority(int handle, int32_t *priority) __EXPORT;

/**
 * @see uORB::Manager::orb_set_interval()
 */
extern int	orb_set_interval(int handle, unsigned interval) __EXPORT;

__END_DECLS

/* Diverse uORB header defines */ //XXX: move to better location
#define ORB_ID_VEHICLE_ATTITUDE_CONTROLS    ORB_ID(actuator_controls_0)
typedef uint8_t arming_state_t;
typedef uint8_t main_state_t;
typedef uint8_t hil_state_t;
typedef uint8_t navigation_state_t;
typedef uint8_t switch_pos_t;

#endif /* _UORB_UORB_H */