pub fn calibrate(reps: u32) -> Result<Calibration, CalError>Expand description
Derive the ns-per-tick calibration factor.
Cold path: brackets reps counter reads between two reference
monotonic-clock reads (repeatable — call again to re-calibrate; see the
drift caveat in README). Two independent measurements must agree within
1% or the counter is rejected (CalError::UnstableCounter).
§Errors
CalError::UnsupportedCounter when the architecture has no counter
or the invariant/frequency check fails; CalError::UnstableCounter
when the two bracketed measurements disagree beyond 1%;
CalError::NoProgress when the counter does not advance;
CalError::NoReferenceClock when no reference monotonic clock exists.
REQ-CLK-003.