Struct AsyncWeightedSemaphore 

pub struct AsyncWeightedSemaphore { /* private fields */ }

A semaphore admitting weighted permits under a runtime-adjustable capacity limit.

Acquisition waits until the in-flight weight plus the requested weight fits under the current limit. The limit can be raised or lowered while permits are held; a single permit whose weight exceeds the limit is admitted when nothing else is in flight, so it cannot deadlock.

Implementations

impl AsyncWeightedSemaphore

pub fn new(limit: u64) -> Arc<Self>

Create a semaphore with the given initial capacity limit.

pub fn limit(&self) -> u64

Current capacity limit

pub fn in_flight(&self) -> u64

Total weight currently held by live permits

pub fn set_limit(&self, new_limit: u64)

Change the capacity limit. Raising it wakes waiters to re-check; lowering it applies backpressure, waiting acquisitions until in-flight weight drains.

pub fn raise_limit(&self, candidate: u64) -> u64

Raise the limit to at least candidate, never lowering it; wakes waiters if raised. Returns the previous limit so callers can detect/log an actual raise.

Monotonic: a candidate at or below the current limit is a no-op.

pub fn try_acquire( self: &Arc<Self>, weight: u64, ) -> Option<AsyncWeightedSemaphoreGuard>

Try to acquire weight units without waiting.

Never blocks. On success the guard holds the weight until dropped. A zero-weight request always succeeds and accounts nothing.

pub async fn acquire( self: &Arc<Self>, weight: u64, ) -> AsyncWeightedSemaphoreGuard

Acquire weight units, waiting until they fit under the current limit.

Blocks until enough weight drains (or the limit is raised). The returned guard holds the weight until dropped. No deadlock timeout: an over-limit request is admitted only when nothing else is in flight.

Trait Implementations

impl Debug for AsyncWeightedSemaphore

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

Formats the value using the given formatter.