Expand description
Metered timer wheel: thin wrapper around the base TimerWheel
that tracks per-instance counters. Counters are plain u64
fields - no atomics, no locks - because the underlying wheel is
itself single-threaded. Pair with the concurrent feature for a
thread-safe metered surface (wrap a MeteredTimerWheel inside a
mutex of your own).
cascade_events is always 0 for the single-level base wheel.
It’s tracked here so downstream code that swaps the wheel for
the hierarchical variant doesn’t need a schema change in the
metrics snapshot. The hierarchical wheel exposes its own
cascades() counter directly; see that module.