Build 2's first two items, L4 and L5, picked ahead of the rest of the
latency tier because the field data argues for them: a five-pod race on
4.12.233 kept time well - send interval median and p95 both ~32 ms - but
every pod saw gaps of one to two seconds, and corrections as large as
2702 metres against a mean under a metre. That is not a timing problem,
it is a pod flying most of the way across the map on stale velocity and
being yanked back through whatever it passed.
L5, the extrapolation clamp. Both dead reckoners carried
lastPerformance - lastUpdate into the projection unbounded once past the
expected update. They now stop at kMaximumExtrapolationSeconds, one
second, so a replicant coasts and then parks. A pod that stops and snaps
once reads as the dropped connection it is; a pod sliding confidently
through scenery reads as a broken game, and is far more expensive to
collide with. It matters more in the accelerated reckoner, which also
carries a*t*t/2 and so grows the error as the SQUARE of the silence.
RP412NETCOAST sets the seconds, 0 restores the unbounded coast for an
A/B on one connection. MUST MATCH across a race, same class as
RP412NETPREDICT - it moves replicants, so it decides where they collide.
L4, the stale-record guard. Simulation now remembers the sender's stamp
on the last record it accepted, and the record walk skips one stamped
earlier - such a record winds lastUpdate backwards and has the reckoner
extrapolate from a position the sender has already left. A regression
larger than five seconds is not a late record but a different stream (a
rejoin, a restart, a clock that was set), so that resyncs instead. The
counter NetRaceStats::staleCount has been sitting there reading zero
with a comment saying "until the stale guard ships"; it is now fed.
The guard is asked by the caller rather than done inside
ReadUpdateRecord, because that is virtual and not every override chains
to the base.
Verified: clean Release build; two-pod loopback race green, both pods
scoring, and stale 0 on both - which is the reading that says the guard
does not fire on an ordered stream. The clamp is NOT demonstrated by
that run: the harness parks its pods, so there is no velocity to coast
on. Pod B did see a 9.167 s gap in it, which on a moving pod is the
shape of the field's kilometre corrections.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
CydandClaude Opus 5
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