Struct LeaseTimerWheel 

pub struct LeaseTimerWheel { /* private fields */ }

Timer wheel that schedules leases to fire at specific wall-clock times.

Construct once, share via Arc. Call [schedule] from producer threads, call [run_until_shutdown] on a dedicated worker thread.

Implementations

impl LeaseTimerWheel

pub fn new(granularity_ms: u64) -> Self

New wheel with granularity_ms bucket width (minimum 1 ms).

pub fn schedule(&self, id: LeaseId, expiry: Instant)

Schedule id to fire at or after expiry.

The expiry is snapped forward to the next granularity boundary so near-simultaneous expirations coalesce into a single wake-up. Re-scheduling an existing id silently replaces the prior entry.

pub fn cancel(&self, id: &str)

Cancel a scheduled lease. No-op if id is not scheduled.

pub fn shutdown(&self)

Signal the worker to stop after the current batch (if any) finishes.

pub fn run_until_shutdown(&self, handler: impl FnMut(LeaseId) -> bool + Send)

Block until shutdown() is called or handler returns false.

For each fired lease id, calls handler(id). If the handler returns false, the wheel stops immediately (even mid-batch).

CPU: the thread is parked in Condvar::wait_timeout between buckets. With 10 k idle leases scheduled far in the future the CPU cost is effectively zero — one wake-up per bucket boundary, not per lease.