rcl_subscription_t Struct Reference

#include <nros_generated.h>

Collaboration diagram for rcl_subscription_t:

Data Fields
void *	_executor
size_t	handle_id
struct rclc_node_ref_t	node
struct rclc_qos_t	qos
rclc_sched_context_id_t	sched_context_id
enum rclc_subscription_state_t	state
uint8_t	topic_name [256]
size_t	topic_name_len
uint8_t	type_hash [128]
size_t	type_hash_len
uint8_t	type_name [256]
size_t	type_name_len
const struct rclc_message_type_t *	type_support

Detailed Description

A subscription the executor dispatches (rclc's rcl_subscription_t).

phase-487 W1 (RFC-0096 D9, the C amendment): an entity the executor dispatches is owned by the executor. The subscriber, its receive buffer, the callback and its context all live in the executor arena's entry, and this struct holds the arena handle (handle_id, _executor) plus the DESCRIPTION the registration needs. The description has to be here because rclc's order is init first, rclc_executor_add_* second: at init there is no executor to hold it yet.

Before phase-487 this struct also carried the callback, the context and the polled form's subscriber storage (_opaque). On the dispatched road none of the three was read after registration, because the arena keeps its own copies. A subscription the caller drains itself is a [rclc_polling_subscription_t].

Field Documentation

_executor

void* rcl_subscription_t::_executor

issue 1437 — the rclc_executor_t holding this subscription's arena entry, or NULL before registration. Set beside [handle_id](Self::handle_id) by nros_executor_add_subscription_*: the pair is the same (executor_ptr, arena_entry_index) that ServiceServerInternal and ServiceClientInternal carry.

Internal: treat as opaque.

handle_id

size_t rcl_subscription_t::handle_id

Handle ID from executor registration (SIZE_MAX = not registered)

node

struct rclc_node_ref_t rcl_subscription_t::node

Pointer to parent node

qos

struct rclc_qos_t rcl_subscription_t::qos

QoS settings (stored during init, used by executor registration)

sched_context_id

rclc_sched_context_id_t rcl_subscription_t::sched_context_id

Phase 189.M3 — scheduling-context slot requested via [rclc_subscription_init_with_options]. 0 = inherit the executor / Node default (no explicit bind), matching the rcl_node_options_t::sched_context_id convention. When non-zero, nros_executor_add_subscription_* binds the freshly-created handle to this SC after registration.

state

enum rclc_subscription_state_t rcl_subscription_t::state

Current state

topic_name

uint8_t rcl_subscription_t::topic_name[256]

Topic name storage

topic_name_len

size_t rcl_subscription_t::topic_name_len

Topic name length

type_hash

uint8_t rcl_subscription_t::type_hash[128]

Type hash storage

type_hash_len

size_t rcl_subscription_t::type_hash_len

Type hash length

type_name

uint8_t rcl_subscription_t::type_name[256]

Type name storage

type_name_len

size_t rcl_subscription_t::type_name_len

Type name length

type_support

const struct rclc_message_type_t* rcl_subscription_t::type_support

phase-492 W8 — the descriptor this subscription was created with, kept so rclc_executor_add_subscription_with_context deserialises through its codec with rclc's arguments. Descriptors are generated static consts, so the pointer outlives the subscription.

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The documentation for this struct was generated from the following file:

• include/rclc/detail/nros_generated.h