Struct BarrierPollHandle 

pub struct BarrierPollHandle { /* private fields */ }

Handle used by source operators to poll for pending barriers.

Cloned from CheckpointBarrierInjector::handle and stored in the source operator. The fast path is a single atomic load.

Implementations

impl BarrierPollHandle

pub fn poll(&self, epoch: u64) -> Option<CheckpointBarrier>

Poll for a pending barrier.

Returns Some(CheckpointBarrier) if a barrier is pending and this call successfully claimed it (exactly-once delivery across handles sharing the same injector). Returns None if no barrier is pending or another handle already claimed it.

The epoch parameter is supplied by the caller (typically the source operator’s current epoch) and is embedded in the returned barrier. The injector does not encode the epoch in the atomic command word — only checkpoint ID and flags are packed.

Performance

Fast path (no barrier): single load(Relaxed) — < 10ns. Slow path (barrier pending): one compare_exchange.

Trait Implementations

impl Clone for BarrierPollHandle

fn clone(&self) -> BarrierPollHandle

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BarrierPollHandle

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

Formats the value using the given formatter.