Struct CheckpointBarrierInjector 

pub struct CheckpointBarrierInjector { /* private fields */ }

Cross-thread barrier injector for source operators.

The coordinator thread publishes a barrier command via trigger. Source operators poll via BarrierPollHandle::poll on each iteration of their event loop.

Fast Path

The poll path is a single AtomicU64::load(Relaxed) — typically < 10ns. Only when a barrier is pending does the source perform a compare-exchange to claim it.

Implementations

impl CheckpointBarrierInjector

pub fn new() -> Self

Create a new injector with no pending barrier.

pub fn handle(&self) -> BarrierPollHandle

Get a handle that source operators use to poll for barriers.

pub fn can_trigger(&self) -> bool

Whether no barrier command is currently being published, pending, or consumed. The coordinator uses this as an all-source preflight before fan-out.

pub fn trigger(&self, barrier: CheckpointBarrier) -> bool

Trigger a new checkpoint barrier.

The next BarrierPollHandle::poll call on any source will observe this barrier and return it. Returns false without modifying the pending command if the identity is zero or noncanonical, or if another trigger is being published, is pending, or is being consumed.

Arguments

• barrier - Exact barrier command to publish. checkpoint_id and epoch must name the same nonzero durable checkpoint.

pub fn cancel_exact(&self, barrier: CheckpointBarrier) -> bool

Cancel the pending barrier with this exact checkpoint identity.

Returns true only when this call claims and cancels a pending command whose checkpoint ID and epoch both match. A stale identity, an idle injector, or a barrier already claimed by a poller returns false. Mismatched pending commands remain available to pollers unchanged.

Trait Implementations

impl Clone for CheckpointBarrierInjector

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CheckpointBarrierInjector

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

Formats the value using the given formatter.

impl Default for CheckpointBarrierInjector

fn default() -> Self

Returns the “default value” for a type.