Trait NodeRuntime 

pub trait NodeRuntime {
    // Required method
    fn spin_once(&mut self, timeout_ms: u32) -> Result<(), ()>;

    // Provided methods
    fn apply_lifecycle(&mut self, autostart: u8) -> Result<(), ()> { ... }
    fn apply_param_services(
        &mut self,
        params: &[(&str, &str)],
    ) -> Result<(), ()> { ... }
    fn executor_handle(&mut self) -> *mut c_void { ... }
    fn observed_callback_counts(&self) -> (usize, usize) { ... }
    fn signal_callback(&mut self, _cb: SignaledCallback<'_>) { ... }
    fn dispatch_strategy(&self) -> DispatchStrategy { ... }
}

Phase 214.K.1 — backward-compat alias. The board-side dispatch sink was renamed NodeRuntime → NodeDispatchRuntime to disambiguate from the user-facing nros::NodeRuntime metadata trait. This alias stays for one release cycle so external impl callers (per-board crates outside the tree) get a clear deprecation arrow rather than a hard break. Node runtime sink the codegen-emitted run_plan(runtime) body talks to (Phase 212.N.7 step-3.1).

Object-safe + no_std. The concrete impl (ExecutorNodeRuntime in nros) owns the live executor; BoardEntry::run installs it on the per-boot RuntimeCtx::runtime slot before invoking the user setup closure.

Phase 214.K.1 — renamed from NodeRuntime to disambiguate from the user-facing nros::NodeRuntime metadata-sink trait in packages/core/nros/src/node.rs:112. The two traits live at different layers (board-side dispatch sink vs user-side metadata declaration sink) and the previous shared name forced explicit nros_platform:: / nros:: qualification at every use site + produced confusing impl NodeRuntime for X ambiguity. A #[deprecated] pub use NodeDispatchRuntime as NodeRuntime; re-export sits at the crate module level for one release cycle.

Required Methods

fn spin_once(&mut self, timeout_ms: u32) -> Result<(), ()>

Drive the underlying executor for at most timeout_ms milliseconds. Ok(()) on a clean spin (including timeout); Err(()) if the executor surfaces a spin error.

Result<_, ()> is deliberate: the board entry-point callers (nros-board-{freertos,nuttx,threadx} spin loops) only {:?}-print the error and B::exit_failure() — a typed enum would carry no extra info across the trait boundary, since the underlying ExecutorError from nros::node_runtime is mapped to () at the impl site (impl NodeDispatchRuntime for ExecutorNodeRuntime). #[allow] keeps the surface narrow.

Provided Methods

fn apply_lifecycle(&mut self, autostart: u8) -> Result<(), ()>

Phase 264 W2 — register the REP-2002 lifecycle services on the underlying executor + drive boot autostart. autostart: 0 = none, 1 = configure, 2 = configure+activate. Default no-op (non-executor runtimes, or nros built without lifecycle-services); the ExecutorNodeRuntime impl in nros does the real work behind that feature. nros::main! calls this (via RuntimeCtx::apply_lifecycle) when system.toml declares [lifecycle], mirroring the bake’s generate.rs::render_lifecycle_fn.

fn apply_param_services(&mut self, params: &[(&str, &str)]) -> Result<(), ()>

Phase 264 W4b — register the 6 ROS 2 parameter services on the underlying executor + seed a volatile RAM param store with the launch-baked <param> initials (params is the aggregate (name, value) slice, value as the raw launch string — the impl infers the ParameterValue type). After this, ros2 param list/get/set works against the running node; reconfigured values live in RAM until the next boot (RFC-0004 §10; persistence is out of scope, issue 0080). Default no-op (non-executor runtimes, or nros built without param-services); the ExecutorNodeRuntime impl in nros does the real work behind that feature. nros::main! calls this (via RuntimeCtx::apply_param_services) when system.toml declares [param_services], mirroring the bake’s generate.rs::render_param_persistence_fn.

fn executor_handle(&mut self) -> *mut c_void

Phase 258 (Track 2, 2a) — raw *mut Executor (as void*) for the owned-spin entry, so a Node pkg’s register(runtime) wrapper can call the uniform __nros_component_<pkg>_install(.., executor, ..) seam (nros::install_node_typed) instead of the retired opaque-fn-ptr register_dispatch_slot_dyn bridge. A pointer crosses the nros-platform → nros layering wall cleanly (the concrete ExecutorNodeRuntime lives in nros; this trait can’t name it).

Default null — sinks without a live executor (e.g. NullNodeRuntime, framework-dispatch-only runtimes) report no handle; the install path treats null as a registration error.

fn observed_callback_counts(&self) -> (usize, usize)

Observability counters from hosted/runtime tests.

Returns (all_callbacks, message_callbacks). Implementations that cannot observe callback dispatch keep the default zeros.

fn signal_callback(&mut self, _cb: SignaledCallback<'_>)

Hand a signaled callback to the framework-side dispatcher (Phase 216.A.2). Only meaningful for DispatchStrategy::Deferred (RTIC / Embassy) runtimes — Inline runtimes drive callbacks directly from spin_once and never call this. The default panic surfaces the mis-wire loudly rather than silently dropping the callback signal.

fn dispatch_strategy(&self) -> DispatchStrategy

Declare how this runtime delivers callbacks (Phase 216.A.2). nros check (Phase 216.D.1) cross-validates each Node pkg’s Node::DISPATCH against this value. Defaults to Inline so every existing impl reports the historical behavior unchanged.

Implementors

impl NodeDispatchRuntime for NullNodeRuntime