Module timer 

Timer wheel for one-shot timeouts.

The wheel uses millisecond ticks, bucketed timer references, and an index map. Scheduling and cancellation update only one bucket/index entry each, giving O(1) insertion and cancellation without a sorted list, binary heap, or priority queue.

Structs

ExpiredTimer

Expired timer returned by TimerWheel::tick / TimerWheel::tick_at.

TimerEntry

Timer entry metadata stored in the wheel index.

TimerRef

Unique timer reference used for cancellation.

TimerWheel

Millisecond-granularity O(1) timer wheel for one-shot timers.