Struct UserAnchor 

pub struct UserAnchor<U> { /* private fields */ }

Non-owning weak capability to the user lane (address-table endpoint). Holds no liveness: the lane closes when the last counting UserSender drops even while anchors are held. Every delivery first atomically acquires a temporary live UserSender, so a delivery racing the last sender drop either linearizes entirely before UserLaneClosed or fails with its payload entirely after.

Under cfg(loom) the anchor holds a strong Arc instead of a Weak (loom’s Arc has no downgrade): the semantic liveness is governed by the senders counter, NOT the strong count, so the model stays faithful — the strong-ref distinction is pure memory reclamation, covered on hardware by tests/leak.rs.

Implementations

impl<U> UserAnchor<U>

pub fn upgrade(&self) -> Option<UserSender<U>>

Acquire a temporary live UserSender iff the lane is still open.

The liveness increment is CONDITIONAL and atomic — one read-modify- write loop over the live-sender count that succeeds only while the count is nonzero. It never increments zero, so it can never resurrect a closed lane; a last-sender drop racing this upgrade is caught by the RMW reading zero, and the upgrade then fails with no side effect. The returned sender counts as live until dropped — held across an async send, released on success, error, or cancellation.

pub async fn send(&self, item: U) -> Result<(), UserClosed<U>>

Enqueue a user message through a temporary live sender, awaiting capacity (backpressure). The temporary sender stays alive across the await — the lane cannot close while the delivery is in flight — and is dropped on success, error, or future cancellation, releasing its temporary liveness.

Errors

Returns UserClosed carrying item if the lane is closed (no live counting sender, or the consumer is gone).

pub fn try_send(&self, item: U) -> Result<(), TrySendError<U>>

Enqueue a user message without blocking, through a temporary live sender.

Errors

TrySendError::Closed carrying item if the lane is closed (no live counting sender, or the consumer is gone); TrySendError::Full if the lane is at capacity.

Trait Implementations

impl<U> Clone for UserAnchor<U>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.