Struct PubMonitorCell 

pub struct PubMonitorCell {
    pub count: AtomicU32,
    pub max_latency_us: AtomicU32,
    pub last_publish_stamp_age_us: AtomicU32,
}

One contracted publisher’s counters. Baked as a static by codegen (or declared by the fixture); the publisher handle bumps count on every publish, the executor reads deltas on spin ticks.

Fields

count: AtomicU32

max_latency_us: AtomicU32

W3b.5 — max observed take→publish latency (µs) in the current check window. Written by the dispatch loop (fetch_max), drained (swap 0) by the latency check.

last_publish_stamp_age_us: AtomicU32

Age of the stamp this publisher last put ON THE WIRE, in microseconds: epoch_now - outgoing header.stamp.

Distinct from max_latency_us, which times this node’s own take→publish work. This says how old the DATA is that the node just published, which is the quantity a chain is made of.

It exists to answer a question max-age-runtime cannot. That rule measures epoch_now - stamp on the TAKE path, so if every node in a chain propagates the original stamp – the usual ROS convention, each node copying its input’s stamp to its output – the age at the final consumer already IS the end-to-end latency. If any node re-stamps with now, the clock silently resets and the same number becomes single-hop age instead. Same units, same magnitude, no warning.

A publish age near zero on a node that consumes input is the signature of re-stamping. Recording it here is what lets a chain’s provenance be checked at all, rather than assumed.

0 = never observed, matching the other cells: the type has no STAMP_OFFSET, or no epoch source is installed.

Implementations

impl PubMonitorCell

pub const fn new() -> Self

Trait Implementations

impl Debug for PubMonitorCell

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for PubMonitorCell

fn default() -> PubMonitorCell

Returns the “default value” for a type.