Eight review findings on FrameDecoder's accumulated-scalar rule.
The squeeze that pulls a leading timeline back was expressed as a fraction of
the NOMINAL burst width, which cannot converge: inside one timestamps() call
the wall clock is frozen, so any positive step raises the lead measured at that
instant, and the lead only falls because the wall advances between packets. At
the kMinBleedFactor floor the timeline still gained 0.05 * nominal per packet,
so a declared SamplingRate of 30 against a producer really flushing 10 samples
at 1 kHz ran away without bound (667 s of lead after 1000 s of stream). Cap the
burst's total advance at half the wall time really elapsed since this signal's
previous burst instead, and the lead strictly falls for any declared rate.
SigState gained lastEmittedWall for that reference; lastPacketWall could not be
reused because it belongs to packetBurst.
The hrt branch contributed zero elapsed for a late datagram but still wrote the
hrt reference back to it, so the next packet's delta spanned two intervals and
fabricated a whole extra packet of producer time — permanently, since the
monotonic clamp discards the correction ClockOffset would have made. Reordering
is reachable in production: udps_client.c only counts counter gaps. Simply
never regressing the reference is not the fix either, because a producer restart
would then freeze the signal forever, so the two are now separated by the size
of the backward jump.
The hrt branch's clamp was also one-directional, reintroducing on that branch
exactly the defect the declared branch's squeeze exists to prevent: a backward
wall step (NTP, suspend/resume) left a permanent lead. It now shares the same
wall-elapsed cap.
Also: anchor an hrt-branch burst's LAST element on arrival, matching the
declared branch, so two accumulated scalars in one scope do not sit a burst
apart on the shared X axis; treat a non-finite samplingRate off the wire as
undeclared, since +inf produced a 0.0/0.0 factor the floor could not catch and
turned every stamp NaN; write lastCounter on the hrt branch so duplicate
datagrams are dropped there too; and correct two comments that argued for the
current code with claims that are false (a counter-gap clamp reaches the
opposite outcome, not the same one earlier, and the squeeze's steady state is a
sawtooth, not a fixed offset).
Seven new tests, each proven non-vacuous by sabotage; 54 pass. Plan document
Task 4 re-synced and its stale test count and "agree on the same stream" claim
corrected.
Martino Ferrari
440b805afd