PX4-Autopilot/platforms/common/uORB/uORB.h

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#pragma once

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

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

typedef uint16_t orb_id_size_t;

/**
 * Object metadata.
 */
struct orb_metadata {
	const char    *o_name;              /**< unique object name */
	const uint16_t o_size;              /**< object size */
	const uint16_t o_size_no_padding;   /**< object size w/o padding at the end (for logger) */
	uint32_t message_hash;	/**< Hash over all fields for message compatibility checks */
	orb_id_size_t  o_id;                /**< ORB_ID enum */
	uint8_t o_queue;					/**< queue size */

};

typedef const struct orb_metadata *orb_id_t;

/**
 * Maximum number of multi topic instances. This must be <= 10 (because it's the last char of the node path)
 */
#if defined(CONSTRAINED_MEMORY)
# define ORB_MULTI_MAX_INSTANCES 4
#else
# define ORB_MULTI_MAX_INSTANCES 10
#endif

/**
 * 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 (used by code generators).
 *
 * @param _name		The name of the topic.
 */
#if defined(__cplusplus)
# define ORB_DECLARE(_name)		extern "C" const struct orb_metadata __orb_##_name __EXPORT
#else
# define ORB_DECLARE(_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.
 * @param _size_no_padding	Struct size w/o padding at the end
 * @param _message_hash	32 bit message hash over all fields
 * @param _orb_id_enum	ORB ID enum e.g.: ORB_ID::vehicle_status
 * @param _queue_size Queue size from topic definition
 */
#define ORB_DEFINE(_name, _struct, _size_no_padding, _message_hash, _orb_id_enum, _queue_size)               \
	const struct orb_metadata __orb_##_name = {     \
		#_name,                                 \
		sizeof(_struct),                \
		_size_no_padding,                       \
		_message_hash,                          \
		_orb_id_enum,                           \
		_queue_size                             \
	}; struct hack

__BEGIN_DECLS

int uorb_start(void);
int uorb_status(void);
int uorb_top(char **topic_filter, int num_filters);

/**
 * 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) __EXPORT;

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

/**
 * @see uORB::Manager::orb_publish()
 */
extern int orb_publish(const struct orb_metadata *meta, orb_advert_t handle, const void *data) __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
 */
static inline int orb_publish_auto(const struct orb_metadata *meta, orb_advert_t *handle, const void *data,
				   int *instance)
{
	if (!*handle) {
		*handle = orb_advertise_multi(meta, data, instance);

		if (*handle) {
			return 0;
		}

	} else {
		return orb_publish(meta, *handle, data);
	}

	return -1;
}

/**
 * @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_check()
 */
extern int	orb_check(int handle, bool *updated) __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_set_interval()
 */
extern int	orb_set_interval(int handle, unsigned interval) __EXPORT;

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

/**
 * Returns the C type string from a short type in message fields metadata, or nullptr
 * if not a short type
 */
const char *orb_get_c_type(unsigned char short_type);

/**
 * Returns the queue size of a topic
 * @param meta orb topic metadata
 */
extern uint8_t orb_get_queue_size(const struct orb_metadata *meta);

/**
 * Print a topic to console. Do not call this directly, use print_message() instead.
 * @param meta orb topic metadata
 * @param data expected to be aligned to the largest member
 */
void orb_print_message_internal(const struct orb_metadata *meta, const void *data, bool print_topic_name);

__END_DECLS

/* Diverse uORB header defines */ //XXX: move to better location
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;