Topic subscription API. More...

#include "rclc/types.h"
#include "rclc/detail/declared_qos.h"
#include "rclc/rclc.h"

Include dependency graph for subscription.h:

This graph shows which files directly or indirectly include this file:

Functions
static rcl_ret_t	rclc_subscription_init_best_effort (struct rcl_subscription_t subscription, const struct rcl_node_t node, const struct rclc_message_type_t type_info, const char topic_name)
	rclc's best-effort preset constructor for a subscription.

Detailed Description

Topic subscription API.

Create a subscription with rclc_subscription_init_default() (or rclc_subscription_init_with_qos()) and add it to an executor, which owns its subscriber and its callback: rclc_executor_add_subscription_with_context() delivers deserialised messages (rclc's own six arguments), rclc_executor_add_subscription_raw() CDR bytes.

For manual polling with no executor, use the separate type rclc_polling_subscription_t: create it with rclc_polling_subscription_init() and drain it with rclc_polling_subscription_take() (deserialised, the rcl_take analog) or rclc_polling_subscription_take_serialized() — or rclc_polling_subscription_take_sequence() for a batch and rclc_polling_subscription_take_validated() for the E2E-safety variant. The two types are separate since phase-487: a dispatched subscription's storage is in the executor arena, a polled one's is in the struct.

Function Documentation

◆ rclc_subscription_init_best_effort()

static rcl_ret_t rclc_subscription_init_best_effort	(	struct rcl_subscription_t *	subscription,
		const struct rcl_node_t *	node,
		const struct rclc_message_type_t *	type_info,
		const char *	topic_name
	)

inlinestatic

rclc's best-effort preset constructor for a subscription.

phase-417 W5.d; the sibling of rclc_publisher_init_best_effort() and the same argument. rclc's body (rclc/src/rclc/subscription.c @ 10eadcc) is rclc_subscription_init(..., &rmw_qos_profile_sensor_data) — best-effort, volatile, KEEP_LAST(5) — which RCLC_QOS_SENSOR_DATA mirrors.

Takes no callback, at rclc's arity: the callback is supplied at registration by rclc_executor_add_subscription_raw(), exactly where rclc supplies it (rclc_executor_add_subscription). That is the same split rclc_subscription_init_default already makes, so the two presets differ only in the profile they pass.

static inline: no symbol, no writable data.

Parameters

[out]	subscription	Zero-initialised subscription to fill in.
[in]	node	An initialised node.
[in]	type_info	Generated message type descriptor.
[in]	topic_name	Topic name, null-terminated.

Returns: Whatever rclc_subscription_init_with_qos() returns.

Functions

Detailed Description

Function Documentation

◆ rclc_subscription_init_best_effort()