session_over_one_router asserted that a latest subscriber must drop
snapshots. bus-v1 section 7 says a latest subscription replaces an
undelivered value; it lets a consumer miss values, it does not oblige it
to. Under contention the publisher was slow enough that the renderer kept
up, saw all twenty snapshots and the test failed on conforming behaviour:
16 of 40 runs beside four busy loops, and 9 of 20 whole-crate runs.
The renderer is now held until the publisher's completion is observed
rather than until a timer expires, so the coalescing is forced instead of
raced for: the subscription keeps the one delivery in flight and one
replaceable queued value, and the renderer receives snapshots 1 and 20 of
20. The assertions are the guarantees that hold -- what arrives is in
publication order, the last value is the latest published, the stalled
spectator never refuses a publication or drops out of the fan-out, and
every snapshot the renderer missed is counted as a replacement to the
publisher at admission and to the renderer on delivery, so nothing is
lost silently.
Three more tests in the crate asserted the same kind of race:
- latest_replay_is_ordered_ahead_of_a_racing_publish demanded the
non-coalesced outcome of a race section 7 allows either way ("bounded
mode preserves that order, while latest mode may coalesce it"). It now
puts one racing publication to a bounded and a latest subscription at
once: bounded must deliver the replay and then the publication, and the
latest branch is chosen by that publication's own replaced count.
- collection_waits_for_every_retained_owner, and the two disconnect
cleanup tests beside it, read the store directory for the unlink that
follows the registry update outside the router lock. They use
settle_files, like every other unlink check in the suite.
- The demo example printed a root count taken before the producer's own
release had reached the router, so the line the guide quotes was a
race. It waits for the release, the same way it already waits for
collection; the printed output is unchanged.
Nothing under flybus/src is touched: no routing defect was found. The
conformance rows for the credit/queue split, the replaced count, the
replay ordering and the latest spectator that cannot refuse a publication
now cite what each rewritten test actually varies.
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