The register said "two remaining holes now closed" and the SPEC's Current:
still described `push_blocking`, which parking replaced. Both now match the
code.
Three additions, in the order they surfaced:
(c) FilterNode and RouterNode were the last data paths still using the
throwing push() with the exception swallowed, so a full output discarded
the value — including the EOF sentinel. The decimator passes EOF by
predicate but its output is reliably full, the embedder being the slowest
node, so the token went nowhere and nothing downstream shut down. That is
the wedge the runs were being killed for, and it is worth the register
saying so plainly.
(d) The sentinel could be delivered ahead of a value still queued behind it,
losing the tail to any consumer treating EOF as a hard stop.
(e) Two firings of one node could overlap, which breaks the one-slot park
itself: a parked value can be overwritten with no drop recorded.
(e) also corrects (b). The startup lost wake was recorded as a missed
empty->non-empty edge closed by a level-triggered re-check; the actual cause
was the callbacks being written while a running neighbour read them — ten
ThreadSanitizer races — and they are now installed in a prepare() pass before
any node starts. The re-check stays and is still needed, but for a benign
ordering rather than as cover for a race.
Two things the requirement now carries that it did not before. A channel holds
at most one undelivered sentinel: a second is refused and reported rather than
silently overwriting the first, which matters the moment a pipeline is reused
for a second input. And a lossless decimator is a backpressure point rather
than a relief valve, so the source throttles to the face branch instead of
quietly thinning it — what the requirement asks for, but it changes the shape
of a loaded run and is not yet benchmarked.
The Gap is unchanged and still open: capacity is counted in items, not bytes,
so a crowd frame carrying 60 crops occupies one slot exactly as an empty one
does. AR-004 stays **Mostly** for that reason.
Verification plan updated with the cases the KPN suite now pins.
TRACES: AR-004 | SR-002
dtourolle
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