Enum BackPressureError 

pub enum BackPressureError {
    Saturated,
    DeadlineNear,
    DeadlineElapsed,
}

Errors returned by the deadline-aware back-pressure acquire path.

Distinct from AbiError so callers that want to discriminate “saturated forever” from “saturated because the per-instance deadline is approaching” can do so without having to inspect the surrounding context. Conversions to AbiError (for back-compat with the existing host-function return path) collapse both deadline variants onto AbiError::QuotaExceeded — the guest sees the same “no permits available” signal it already handles, and the richer variant survives in logs / metrics that bind directly to BackPressureError.

Variants

Saturated

The semaphore is saturated and (for the cap-0 sentinel) will never release a permit. Equivalent to the historical AbiError::QuotaExceeded surface — kept under that name so the conversion path is unambiguous.

DeadlineNear

The configured per-invocation deadline is within DEADLINE_NEAR_WINDOW of elapsing. In-flight permits are allowed to complete; new acquires are refused so the cohort drains under bounded budget.

DeadlineElapsed

The configured per-invocation deadline has already elapsed. All future acquires (including pending awaiters that have not yet observed a permit) are rejected.

Implementations

impl BackPressureError

pub fn name(self) -> &'static str

Stable, human-readable name (used for log fields).

Trait Implementations

impl Clone for BackPressureError

fn clone(&self) -> BackPressureError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for BackPressureError

impl Debug for BackPressureError

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

Formats the value using the given formatter.

impl Eq for BackPressureError

impl From<BackPressureError> for AbiError

fn from(e: BackPressureError) -> Self

Converts to this type from the input type.

impl PartialEq for BackPressureError

fn eq(&self, other: &BackPressureError) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for BackPressureError