Crate nros

Expand description

§nros

A lightweight ROS 2 client library for embedded systems.

This crate provides a unified API for building ROS 2 nodes in Rust, with support for no_std environments and embedded targets.

§Features

no_std compatible: Works on bare-metal and RTOS targets
Zero-copy where possible: Minimizes memory allocations
Type-safe: Compile-time verification of message types
ROS 2 compatible: Interoperates with standard ROS 2 nodes via rmw_zenoh

§Quick Start

use nros::prelude::*;
use std_msgs::msg::Int32;

let config = ExecutorConfig::from_env().node_name("my_node");
let mut executor = Executor::open(&config)?;

let node = executor.node_builder("my_node").build()?;
let publisher = executor.node_mut(node).create_publisher::<Int32>("/my_topic")?;
publisher.publish(&Int32 { data: 42 })?;

executor.node_mut(node).create_subscription::<Int32, _>("/topic", |msg: &Int32| {
    println!("Received: {}", msg.data);
})?;

executor.spin(SpinOptions::default());

§Executor Sizing

The executor’s static memory layout is controlled via environment variables at build time:

NROS_EXECUTOR_MAX_CBS (default 4) — maximum number of registered callbacks (subscriptions + timers + services + guard conditions).
NROS_EXECUTOR_ARENA_SIZE (default 4096) — byte budget for storing callback closures inline.

A subscription’s arena receive buffer is sized from the MESSAGE TYPE’s own serialized bound (phase-392 W3c), not from that knob, wherever the bound is reachable. .rx_buffer::<N>() is the opt-out: it says “give me exactly N bytes per slot” and skips the derivation, which is what a peer that pads or a .msg bound looser than the traffic needs (e.g. node_mut(id).subscription(t).typed::<M>().rx_buffer::<4096>().build(cb)).

§Transport Backends

Phase 248 C5c — nros is RMW- and platform-AGNOSTIC. It carries only the rmw-cffi vtable; the concrete backend (zenoh / xrce / cyclonedds) enters the link graph via the board crate (embedded), the board-less app’s own nros-rmw-* dep (native), or the nros-c/nros-cpp staticlib root (D3), and self-registers through the RMW_INIT_ENTRIES walker at Executor::open. The concrete session type is resolved automatically; advanced users can access it via nros::internals::RmwSession.

§Crate Features

nros exposes only FUNCTIONAL features — std/alloc, the rmw-cffi vtable, lending, bridge/config, param-services, lifecycle-services, safety-e2e, stream, ffi-sync, and the ROS edition (ros-humble/ros-iron). There are NO platform-* or concrete rmw-* selector features (Phase 248 C7). Platform + RMW are selected by the board / staticlib root via dependencies, not nros features. The zephyr_component_main! entry macro is gated only on rmw-cffi (it’s framework entry codegen, like nros::main!), not a platform feature.

ROS edition (select one; RFC-0056 — the per-distro interop profile):

ros-humble - ROS 2 Humble (default; TypeHashNotSupported, XCDR1)
ros-iron - ROS 2 Iron (RIHS01 type hash)
ros-jazzy - ROS 2 Jazzy (RIHS01; XCDR2/appendable is phase-303)

Other:

std (default) - Enable standard library support
alloc - Enable heap allocation without full std

§Further Reading

guide — tutorials: getting started, services, configuration, ROS 2 interop, and troubleshooting
Message Generation — codegen reference (all options, output structure, bundled interfaces)
Environment Variables — complete buffer tuning reference
ROS 2 Interop — protocol details (key expressions, liveliness, attachments)
Examples — working examples by platform (native, QEMU, ESP32, Zephyr)

Re-exports§

pub use retired_env::RETIRED_ENV_VARS;
pub use env::ExecutorConfigEnvExt;
pub use env::rmw_selector;
pub use init::ContextSource;
pub use init::InitError;
pub use init::InitOptions;
pub use init::Context;
pub use init::init;
pub use init::init_with_args;
pub use node::ActionExecutor;
pub use node::Callback;
pub use node::CallbackCtx;
pub use node::ClientDispatch;
pub use node::EntityBounds;
pub use node::NodeActionClient;
pub use node::NodeActionServer;
pub use node::NodeDeclError;
pub use node::NodeOptions;
pub use node::NodeParameter;
pub use node::NodePublisher;
pub use node::NodeResult;
pub use node::NodeRuntime;
pub use node::NodeServiceClient;
pub use node::NodeServiceServer;
pub use node::NodeSubscription;
pub use node::NodeTimer;
pub use node::PublisherResolver;
pub use node::TickCtx;
pub use node::CallbackEffects;
pub use node::Component;
pub use node::DeclarativeNode;
pub use node::ExecutableNode;
pub use node::NodeContext;
pub use node_metadata::SourceMetadataExport;
pub use node_metadata::CallbackEffectKind;
pub use node_metadata::CallbackEffectMetadata;
pub use node_metadata::EntityKind;
pub use node_metadata::EntityMetadata;
pub use node_metadata::MetadataRecorder;
pub use node_metadata::MetadataString;
pub use node_metadata::NodeMetadata;
pub use node_metadata::NodeMetadataError;
pub use node_metadata::ParameterDefault;
pub use node_metadata::SourceLocationMetadata;
pub use node_metadata::SourceNameKind;
pub use dispatch_tag::ActionTag;
pub use dispatch_tag::ServiceTag;
pub use dispatch_tag::SubscriptionTag;
pub use node_runtime::ComponentSlotStorage;
pub use node_runtime::install_node_typed_in;
pub use node_runtime::install_node_typed_with_launch_in;
pub use node_runtime::ExecutorError;
pub use node_runtime::ExecutorNodeRuntime;
pub use node_runtime::RegisteredNode;
pub use node_runtime::install_node_typed;
pub use node_runtime::install_node_typed_with_launch;
pub use node_runtime::install_node_typed_with_node_identity;
pub use node_runtime::install_node_typed_with_params;
pub use nros_core::heapless;

Modules§

cdr: CDR encapsulation constants and helpers for FFI layers that handle raw CDR bytes (e.g. nros-c, nros-cpp action and service paths).
config: Build-time runtime configuration — phase-391 W5.
contract: Contract monitors on target, and the /diagnostics reporter they publish through — issues 1635 and 1676, ONE implementation for every language.
derive: Derive macros for message types
dispatch_tag: Phase 216.A.4 — tag types Node authors hold on Self::State to match against incoming Callback in ExecutableNode::on_callback.
embedded: Prelude module for convenient imports
env: issue 0687 — the hosted edge of configuration: every env var nano-ros honours is read here, and the core takes values. The hosted edge of configuration: the process environment.
executor_handle: Issue 1535 — what a void* executor handle crossing the language seam is, and the one check every seam in this crate makes before treating it as an Executor (a C/C++ entry’s handle is an nros-cpp context, not one). Issue 1535 — what a void* executor handed across the language seam IS.
guide: Tutorials and guides for using nros.
host_env: Issue 1763 — the same env rung for a #![no_std] image inside a host process (threadx-linux, freertos-posix), read with the C library’s getenv. target_os = "linux" is “a C library is linked” on this tree. Compiled on every Linux build, not only not(feature = "env") ones: feature unification can turn nros/env on under a caller whose own env is off, and the caller must still find this. Where a caller has env, it uses the std::env reader instead (nros-c/nros-cpp resolve_boot). Issue 1763 — the boot-config ENV rung for a #![no_std] image that still runs inside a host process, read through the C library’s getenv.
init: Phase 212.L.5 — top-level init API; phase-427 W9 — on every target.
internals: Backend-specific internal types.
lifecycle: Re-export of the full lifecycle module so examples can reach LifecycleCallbackSlot, LifecyclePollingNodeCtx, etc.
logging: The whole logging facade — sinks, the early-record ring, the throttle primitives, init/flush/add_sink.
monitor
node: Rust component API shared by metadata discovery and generated runtimes.
node_metadata: Node source metadata recorded without opening middleware.
node_runtime: Phase 212.M.5.a.2 — executor-backed component runtime.
port_park: phase-436 W7 — installing a port’s park primitive, with the wake-object constraint stated once. Board entries reach it through this facade because that is the dependency they already carry.
prelude
qos: The five presets under their older, shorter names.
retired_env: phase-484 W8c — the retired env aliases both hosted readers refuse. phase-484 W8c — the RETIRED runtime env aliases and their canonical names.
runtime_storage: Caller-supplied storage for the component pool — phase-391 W5, step 2.
sizes: Compile-time opaque storage sizes for FFI consumers.
time: Monotonic time for portable node code (issue #504).

Macros§

declarative_component: Emit a no-op ExecutableNode impl for a declarative-only component (W.5.1). The generated runtime calls on_callback unconditionally, so a component instantiated into a generated binary must impl ExecutableNode; components without callback bodies use this to satisfy that contract:
force_link_backend: Define Zephyr’s rust_main for a self-bringup Rust component package.
log_debug: Emit at crate::Severity::Debug.
log_error: Emit at crate::Severity::Error.
log_fatal: Emit at crate::Severity::Fatal.
log_info: Emit at crate::Severity::Info.
log_warn: Emit at crate::Severity::Warn.
nros_debug_throttle: Emit at crate::Severity::Debug, at most once per interval_ms at this call site.
nros_debug_throttle_at: Emit at crate::Severity::Debug, at most once per interval_ms at this call site, measured against the now_ns the CALLER supplies.
nros_error_throttle: Emit at crate::Severity::Error, at most once per interval_ms at this call site.
nros_error_throttle_at: Emit at crate::Severity::Error, at most once per interval_ms at this call site, measured against the now_ns the CALLER supplies.
nros_fatal_throttle: Emit at crate::Severity::Fatal, at most once per interval_ms at this call site.
nros_fatal_throttle_at: Emit at crate::Severity::Fatal, at most once per interval_ms at this call site, measured against the now_ns the CALLER supplies.
nros_info_throttle: Emit at crate::Severity::Info, at most once per interval_ms at this call site.
nros_info_throttle_at: Emit at crate::Severity::Info, at most once per interval_ms at this call site, measured against the now_ns the CALLER supplies.
nros_trace: Emit at crate::Severity::Trace.
nros_trace_throttle: Emit at crate::Severity::Trace, at most once per interval_ms at this call site.
nros_trace_throttle_at: Emit at crate::Severity::Trace, at most once per interval_ms at this call site, measured against the now_ns the CALLER supplies.
nros_warn_throttle: Emit at crate::Severity::Warn, at most once per interval_ms at this call site.
nros_warn_throttle_at: Emit at crate::Severity::Warn, at most once per interval_ms at this call site, measured against the now_ns the CALLER supplies.
panic_halt
panic_to_platform
rx_buffer_for: Route this image’s panics to its platform — phase-366 W5.c / RFC-0077.
zephyr_component_main

Structs§

ActionClient: Typed action client handle.
ActionClientCore: Type-agnostic action client core handling the raw-bytes protocol.
ActionServer: Typed action server with goal state management.
ActionServerCore: Type-agnostic action server core handling the raw-bytes protocol.
ActionServerHandle: Handle to an action server registered in the executor’s arena.
ActionServerRawHandle: Handle to a raw (untyped) action server registered in the executor’s arena.
ActiveGoal: Active goal tracking for action server.
BakedBootConfig: Build-time-baked boot config, emitted (in W4b) into the .nros_boot_config linker section by the entry macro / cmake. Fixed-size + pointer-free so a future post-link tool can patch it in place (RFC-0045). The resolver reads it on embedded via BootConfig::from_baked (in nros-node).
BootConfig: Session-identity subset a caller supplies to ExecutorConfig::resolve.
CdrReader: CDR reader for deserialization
CdrWriter
Clock: A clock for querying time
CompletedGoal: Completed goal with result.
Duration: ROS Duration representation
EmbeddedPublisher: Typed publisher handle.
EmbeddedRawPublisher: Typeless publisher handle. Use when the wire format is not ROS CDR (e.g. PX4 uORB raw POD bytes, custom binary protocols).
EmbeddedServiceClient: Typed service client handle with internal buffers.
EmbeddedServiceServer: Typed service server handle with internal buffers.
Executor
ExecutorConfig: Configuration for opening an embedded executor session.
ExecutorSizing: Per-entry executor sizing — the entity counts an Executor is built to hold. Public + non-generic (the “C/C++ is a thin wrapper” principle): the entry / macro / FFI supplies these as plain usizes rather than as type/const generics C can’t name. Used to size + carve the backing.
FeedbackStream: A stream of feedback messages from an action server.
FloatingPointRange: Floating point range constraints for parameters
GoalFeedbackStream: A goal-filtered feedback stream.
GoalId: Unique identifier for a goal
GoalInfo: Information about a goal
GoalStatusStamped: Goal status with associated goal info
GuardCondition: Handle for triggering a guard condition from outside the executor.
HandleId: Opaque handle identifier returned by registration methods.
HandleSet: A set of handle IDs, represented as a bitset.
IntegerRange: Integer range constraints for parameters
LifecyclePollingNode: Standalone lifecycle state machine for no_std environments.
LogRecord: One log entry, handed to each LogSink.
Logger: A named logger with a runtime severity threshold.
MandatoryParameter: A parameter that must always have a value
MessageInfo: Metadata about a received message
Node: A ROS 2 node — rclrs’s Node, and the ONE node type (phase-483 W2).
NodeKey: Which node a parameter belongs to.
OnSetContext: Two machine words of caller context, carried verbatim to an OnSetParameterFn.
OnSetParameterHandle: A registered OnSetParameterFn, returned by ParameterServer::add_on_set_parameters_callback and consumed by ParameterServer::remove_on_set_parameters_callback.
OptUs: Optional time field with a sentinel 0 for “absent”.
OptionalParameter: A parameter that may or may not have a value
Parameter: A named parameter with value and optional descriptor
ParameterBuilder: Builder for declaring a typed parameter
ParameterDescriptor: Parameter descriptor containing metadata
ParameterServer: Parameter server over caller-owned storage
ParameterStorage: Backing storage a caller places, then lends to a ParameterServer.
ParameterTable: The slot table a ParameterServer borrows.
Promise: A pending reply from a non-blocking service or action call.
PublishLoan: Writable loan into a EmbeddedRawPublisher’s slot.
PublisherOptions: Options for creating a publisher
QoSOverride: Phase 211.H — one per-topic QoS override, lowered from a ROS 2 qos_overrides.<topic>.<role>.<policy> launch parameter by the planner and baked into a &'static [QoSOverride] table by the entry codegen. The node folds the matching entries into the entity’s QoSProfile at create_publisher / create_subscription time (setup-time, single linear scan, no alloc), before the backend-compat validate_against — so an override the active RMW can’t honour still errors loudly, never a silent downgrade.
QoSPolicyMask: Bitmask of QoS policies a backend can honour. See Session::supported_qos_policies.
QoSProfile: Full DDS-shaped QoS profile. Matches the field set of upstream rmw_qos_profile_t.
RawActionClientSpec: Inputs for raw (untyped) action-client registration.
RawActionServerSpec: Inputs for raw (untyped) action-server registration.
RawActiveGoal: Goal tracked by the core — only GoalId + status, no typed data.
RawMessageInfo: Raw-subscription message info: MessageInfo metadata plus the sample’s wire-level attachment bytes, borrowed for the callback scope.
RawSubscription: Typeless subscription handle. Counterpart of EmbeddedRawPublisher.
ReadOnlyParameter: A parameter whose value cannot be changed after declaration
ReadinessSnapshot: Snapshot of handle readiness at the start of a spin iteration.
RecvView: Read-only view into a RawSubscription’s receive buffer.
RmwConfig: Middleware-agnostic session configuration.
SchedContext: First-class scheduling capability — one SC per scheduling concern, shared by every callback that should run under the same budget / period / deadline / class.
SchedContextId: Identifier for a SchedContext registered with an Executor. 110.B.b adds storage [Option<SchedContext>; MAX_SC]; this index addresses into that array.
ServiceClient: Service client handle
ServiceInfo: Service information for service client/server
ServiceRequest: Service request from a client
ServiceServer: Service server handle
SessionHandle: Phase 228.E — an opaque, Send handle to an Executor’s RMW session.
SessionSpec: Phase 128.F.1 — per-backend session declaration for Executor::open_multi. Each spec names an RMW backend (must match one a backend registered under via nros_rmw_cffi_register_named / the RMW_INIT_ENTRIES linker section) and the locator + domain id to open against it.
ShutdownCallbackHandle: Handle to a registered shutdown hook, returned by Executor::add_pre_shutdown_callback / Executor::add_on_shutdown_callback and consumed by the matching remove_*. rclcpp’s PreShutdownCallbackHandle / OnShutdownCallbackHandle.
SpinOnceResult: Result of a single spin iteration
SpinOptions: Options controlling a blocking spin loop — rclrs’s SpinOptions.
SpinPeriodPollingResult: Result from a single period of polling execution (no_std compatible).
SpinPeriodResult: Result from a single period with monotonic-clock measurement.
Subscription: Typed subscription handle with internal receive buffer.
SubscriptionOptions: Options for creating a subscriber
ThrottleState: Per-call-site throttle window.
TierBackingShort: issue 1571 — the spawned tiers’ executor backing. nros::main! emits one TierExecutorBacking static per tiered entry and hands its slots to the board’s run_tiers, which refuses a short block through check_tier_executor_backing and opens each spawned tier with Executor::open_with_session_slot. Gated like the module it names (has_rmw + alloc in nros-node). issue 1571 — the tier backing a board was handed does not cover the tiers it must spawn. Carries both counts so the refusal names them.
TierExecutorBacking: issue 1571 — the spawned tiers’ executor backing. nros::main! emits one TierExecutorBacking static per tiered entry and hands its slots to the board’s run_tiers, which refuses a short block through check_tier_executor_backing and opens each spawned tier with Executor::open_with_session_slot. Gated like the module it names (has_rmw + alloc in nros-node). issue 1571 — the spawned tiers’ executor backing, N slots in ONE named static that the ENTRY owns.
TierSetupGate: issue 1571 — the spawned tiers’ executor backing. nros::main! emits one TierExecutorBacking static per tiered entry and hands its slots to the board’s run_tiers, which refuses a short block through check_tier_executor_backing and opens each spawned tier with Executor::open_with_session_slot. Gated like the module it names (has_rmw + alloc in nros-node). Issue 1733 — the ONE gate a tier runner holds across each tier’s open-and-setup so no two tiers declare entities on the shared session at once.
TierSetupGuard: issue 1571 — the spawned tiers’ executor backing. nros::main! emits one TierExecutorBacking static per tiered entry and hands its slots to the board’s run_tiers, which refuses a short block through check_tier_executor_backing and opens each spawned tier with Executor::open_with_session_slot. Gated like the module it names (has_rmw + alloc in nros-node). Issue 1733 — proof of holding a TierSetupGate; dropping it opens the gate.
TierTaskMemory: issue 1598 — each spawned tier’s TASK memory (stack + control block): nros::main! emits one TierTaskMemory static per spawned tier, sized from its stack_bytes, and hands the TierTaskMemorySet rows to a board whose tier runner creates the task over them (FreeRTOS xTaskCreateStatic). issue 1598 — one spawned tier’s stack and control block, as ONE named static the entry owns. STACK_U64S is the tier’s stack in 8-byte words; TCB_U64S the control-block region, TIER_TASK_TCB_U64S by default and 0 for a kernel whose control block the port keeps itself (Zephyr’s struct k_thread, issue 1232 — a Rust entry cannot size it).
TierTaskMemoryRaw: issue 1598 — each spawned tier’s TASK memory (stack + control block): nros::main! emits one TierTaskMemory static per spawned tier, sized from its stack_bytes, and hands the TierTaskMemorySet rows to a board whose tier runner creates the task over them (FreeRTOS xTaskCreateStatic). issue 1598 — one spawned tier’s task memory as a board receives it: raw, Copy, no lifetime. The ENTRY owns the bytes (TierTaskMemory); the handout is once-only (TierTaskMemorySet::take), which is what makes the raw pointers exclusive.
TierTaskMemorySet: issue 1598 — each spawned tier’s TASK memory (stack + control block): nros::main! emits one TierTaskMemory static per spawned tier, sized from its stack_bytes, and hands the TierTaskMemorySet rows to a board whose tier runner creates the task over them (FreeRTOS xTaskCreateStatic). issue 1598 — the spawned tiers’ task memory, N rows in spawn (chain) order, behind a once-only latch.
Time: ROS Time representation
TimeTriggeredSchedule: Fixed-size, no_std-friendly cyclic schedule. N is the declared maximum window count; window_count is the active length (callers can build the array up to N and set window_count to the actual size used).
TimeTriggeredWindow: One slot in a time-triggered schedule.
TimerDuration: Duration type for timer periods
TimerHandle: A handle to a timer stored in a node
TimerState: Internal timer state
TopicInfo: Topic information for pub/sub
TransportConfig: Transport session configuration
UndeclaredParameters: Provides access to undeclared parameters in a ParameterServer

Enums§

BootConfigError
CancelResponse: Per-goal cancel decision returned from a server’s cancel callback.
CancelReturnCode: action_msgs/srv/CancelGoal RPC return codes.
ClockType: Type of clock to use for time queries
DeadlineAction: RFC-0052 / phase-296 W3b.5 — what the executor DOES when a dispatched callback runs past its bound SC’s deadline_us. Distinct from DeadlinePolicy (which says where the deadline COMES from); this is the miss REACTION, lowered from the tier table’s deadline_policy string (ignore | warn | skip | fault).
DeadlinePolicy: How an EDF deadline is interpreted relative to a callback firing.
DeclarationError: Why a declaration was refused — phase-417 W4.a.
DeserError: Deserialization error.
DispatchStrategy: How a Node expects its callbacks to fire.
ExecutorSemantics: Data communication semantics for the executor.
GoalResponse: Goal accept/reject response codes
GoalStatus: Goal status states
InvocationMode: Per-callback invocation mode.
LifecycleError: Error type for lifecycle transitions.
LifecycleState: Lifecycle state (REP-2002)
LifecycleTransition: Lifecycle transition (REP-2002)
LoanError: Error type for EmbeddedRawPublisher::try_loan.
NodeError: Error type for generic embedded node operations.
ParameterError: Error type for typed parameter operations
ParameterRange: Range constraints for a parameter
ParameterType: ROS 2 parameter types
ParameterValue: Parameter value container
Priority: Criticality bucket for SchedContext. Phase 110.C uses this to pick which BucketedFifoSet / BucketedEdfSet slot a callback dispatches through; later phases (110.D) map it to OS priority.
QoSDurabilityPolicy: QoS durability policy
QoSHistoryPolicy: QoS history policy
QoSLivelinessPolicy: QoS liveliness policy. Matches DDS LIVELINESS semantics.
QoSOverrideRole: Phase 211.H — which side of a topic a QoSOverride targets. Mirrors the <role> segment of a ROS 2 qos_overrides.<topic>.<role>.<policy> launch parameter.
QoSOverrideValue: Phase 211.H — a single policy value a QoSOverride sets. A typed enum (not a string) so the codegen that bakes these from the plan catches an unknown policy / mistyped value at generation time rather than silently no-op-ing at runtime.
QoSReliabilityPolicy: QoS reliability policy
SchedClass: Scheduling class — picks the runtime queue + selection policy for the contained callbacks.
SerError: Serialization error.
SessionMode: Session mode
SetParameterResult: Result of setting a parameter
Severity: REP-2012 severity levels: rcutils’s five, in rcutils’s order, plus Trace.
ShutdownPhase: Which of the two ordered shutdown phases a hook belongs to.
TimeTriggeredScheduleError: Validation errors for a TimeTriggeredSchedule.
TimerClockSource: Which clock advances a timer (phase-425 W4, RFC-0075-adjacent: this is the distinction rclcpp draws between create_wall_timer and create_timer).
TimerMode: Timer mode (repeating, one-shot, or inert)
TransitionResult: Result of a lifecycle transition callback.
TransportError: Transport error types.
Trigger: Executor-level trigger condition.
WakeSourceId: phase-436 B2 — the other half of the seam, for the boards that now use it.

Constants§

BOOT_SET_DOMAIN: Bit 2 — domain_id field is set.
BOOT_SET_LOCATOR: Bit 1 — locator field is set.
BOOT_SET_NAMESPACE: Bit 3 — namespace field is set.
BOOT_SET_NODE_NAME: Bit 0 — node_name field is set.
DEFAULT_RX_BUF_SIZE: The configured default receive-buffer size (NROS_SUBSCRIPTION_BUFFER_SIZE).
DOMAIN_ID_EXPLICIT_ZERO_C_ABI: Issue #227 — C/C++-ABI escape for an EXPLICIT domain 0.
DOMAIN_ID_MAX: RFC-0045 / issue #206 — maximum valid ROS 2 domain ID. The ROS 2 / DDS convention (RTPS port arithmetic) caps usable domains at 232; values above it are a configuration error in EVERY language front-end (never a silent clamp or silent 0). Mirrored into the generated C header — keep the mirror in sync (the #160 drift class).
EXECUTOR_BACKING_DEFAULT_U64S: issue 1571 — the spawned tiers’ executor backing. nros::main! emits one TierExecutorBacking static per tiered entry and hands its slots to the board’s run_tiers, which refuses a short block through check_tier_executor_backing and opens each spawned tier with Executor::open_with_session_slot. Gated like the module it names (has_rmw + alloc in nros-node). The reservation’s size when nothing overrides it: one default-sized executor’s worth.
MAX_LOGGERS: Maximum number of named loggers that can be registered via register_logger. Beyond this, get_logger returns DEFAULT_LOGGER.
MAX_ON_SET_CALLBACKS: How many on-set-parameters callbacks ONE store holds, across every node.
MAX_WAKE_SOURCES: phase-436 B2 — the other half of the seam, for the boards that now use it.
NROS_BOOT_CONFIG_MAGIC: 0x4E524243 = ASCII “NRBC”. A post-link tool scans for this magic to locate the struct in a firmware image.
NROS_BOOT_CONFIG_VERSION: Layout version — lets the resolver reject a mismatched baked struct.
PUBLISHER_GID_SIZE: Size of the publisher Global Identifier (GID), in bytes.
QOS_PROFILE_ACTION_STATUS_DEFAULT: The action-status preset — reliable + transient-local, depth 1.
QOS_PROFILE_CLOCK: The clock preset — sensor-data shaped with depth 1.
QOS_PROFILE_DEFAULT: Phase 108.B — standard ROS-2-equivalent QoS profiles. Match upstream rmw_qos_profile_default etc. field-by-field. Backends validate against these synchronously at create time; no silent downgrade. rmw_qos_profile_default — reliable, volatile, keep-last(10).
QOS_PROFILE_PARAMETERS: rmw_qos_profile_parameters — reliable, depth 1000.
QOS_PROFILE_PARAMETER_EVENTS: rmw_qos_profile_parameter_events.
QOS_PROFILE_SENSOR_DATA: rmw_qos_profile_sensor_data — best-effort, keep-last(5).
QOS_PROFILE_SERVICES_DEFAULT: rmw_qos_profile_services_default.
QOS_PROFILE_SYSTEM_DEFAULT: rmw_qos_profile_system_default — the RMW implementation’s own defaults.
TIER_TASK_TCB_U64S: issue 1598 — each spawned tier’s TASK memory (stack + control block): nros::main! emits one TierTaskMemory static per spawned tier, sized from its stack_bytes, and hands the TierTaskMemorySet rows to a board whose tier runner creates the task over them (FreeRTOS xTaskCreateStatic). issue 1598 — the control-block region every TierTaskMemory carries, in 8-byte words. An UPPER BOUND over the kernels that take it (a FreeRTOS StaticTask_t on Cortex-M is about a hundred bytes); the port REFUSES a region smaller than its own control block at spawn, by name, so a kernel whose block outgrows this fails loudly rather than overrunning the stack that follows. Rust cannot name a C type’s size at macro time, which is why this one number is a bound and the stack beside it is exact.

Statics§

DEFAULT_LOGGER: Catch-all logger returned when the requested name is not registered (or the intern table is full).

Traits§

BoardConfig: Universal board configuration accessors.
ClientTrait: Service client trait for sending requests.
Deserialize: Trait for types that can be deserialized from CDR format
LogSink: Backend a log record is delivered to.
ParameterVariant: Trait for types that can be used as typed parameters
Publisher: Publisher trait for sending messages.
Rmw: Factory trait for compile-time middleware selection.
RosAction: Trait for ROS 2 action types
RosMessage: Trait for ROS message types
RosService: Trait for ROS service types
SecNanosecMsg: A generated message whose field set is { sec: i32, nanosec: u32 } — builtin_interfaces/msg/Time and its Duration twin.
Serialize: Trait for types that can be serialized to CDR format
ServiceTrait: Service server trait for handling requests.
Session: Transport session trait — the per-process anchor an RMW backend gives to the executor.
SubscriptionTrait: Subscription trait for receiving messages.
Transport: Transport backend trait (legacy).

Functions§

action_channel_type: The per-channel DDS type name for a RAW-registered action server.
arena_size_for: phase-271 — default arena bytes for a per-entry executor holding cbs callback slots. Scales the build-time ARENA_SIZE (which is sized for the default MAX_CBS) linearly by cbs, so a per-entry ExecutorSizing with a caller-chosen cbs gets the same per-slot arena budget the global default used — a fat entry (more callbacks) gets a larger arena, a lean one a smaller one — without a workspace-global NROS_EXECUTOR_ARENA_SIZE. Floored at the full default so no per-entry executor is ever smaller than a single-slot build would have been (the arena is a worst-case upper bound; over-provision is safe, under-provision fails entity creation).
baked_domain_from_c_abi: Map the C/C++ ABI’s u8 domain argument onto the resolver’s baked rung.
check_tier_executor_backing: issue 1571 — the spawned tiers’ executor backing. nros::main! emits one TierExecutorBacking static per tiered entry and hands its slots to the board’s run_tiers, which refuses a short block through check_tier_executor_backing and opens each spawned tier with Executor::open_with_session_slot. Gated like the module it names (has_rmw + alloc in nros-node). issue 1571 — the ONE refusal every board’s run_tiers makes before it opens anything: n_tiers tiers run, one on the boot executor, so n_tiers - 1 must each find a slot. Checked up front rather than at each spawn, so a short block never leaves a half-spawned tier chain.
fully_qualified_name: phase-381 follow-up — the node-FQN join, at the crate root because that is where a user looks after Executor::get_node_names hands them the two halves. nros_node::names also has expand_name / resolve_name, which stay behind node_metadata — they are the entity-name seam, not this. Phase 305 W3 (issue 0255) — the ONE name-resolution seam: ROS 2 source-name expansion (~/relative → FQN, ns=/ collapse) + launch remap substitution (exact-FQN match, first rule wins; no wildcards). Implemented in nros_node::names so both the Rust ExecutorSink and the C-ABI executor-side remap table share one lowering; re-exported here next to SourceNameKind as the source-metadata-level entry point. A node’s fully-qualified name, joined from its two halves.
get_logger: Look up a registered logger by name. Returns DEFAULT_LOGGER if none is registered (call register_logger for a 'static Logger to publish one).
get_or_create_logger: Look up a logger by name, CREATING one if the name is new.
register_logger: Publish logger under its name so subsequent get_logger calls with that name return THIS reference.

Type Aliases§

LifecycleCallbackFn: Lifecycle callback function pointer (no_std compatible).
NextDeadlineFn: phase-436 B2 — the other half of the seam, for the boards that now use it.
OnSetParameterFn: An on-set-parameters callback — phase-417 W4.a.
RawCancelCallback: Raw action cancel callback.
RawGoalCallback: Raw action goal callback that receives CDR bytes without deserialization.
RawServiceCallback: Raw service callback that receives and produces CDR bytes.
RawSubscriptionCallback: Raw subscription callback that receives CDR bytes without deserialization.
ShutdownCallbackFn: A shutdown hook: extern "C" so the same slot serves Rust, C and C++ without a second registry, and so no allocator is involved.
TierExecutorBackingSlot: issue 1571 — the spawned tiers’ executor backing. nros::main! emits one TierExecutorBacking static per tiered entry and hands its slots to the board’s run_tiers, which refuses a short block through check_tier_executor_backing and opens each spawned tier with Executor::open_with_session_slot. Gated like the module it names (has_rmw + alloc in nros-node). issue 1571 — one spawned tier executor’s backing: exactly the words an executor opened with ExecutorSizing::DEFAULT carves.
TimerCallbackFn: Timer callback as a bare function pointer (no_std, no heap required).

Crate nros

Crate nros Copy item path

§nros

§Features

§Quick Start

§Executor Sizing

§Transport Backends

§Crate Features

§Further Reading

Re-exports§

Modules§

Macros§

Structs§

Enums§

Constants§

Statics§

Traits§

Functions§

Type Aliases§

Crate nros