bcae483 made the cache a delivery scheduler (tickets, _deliveryGate turn
waits, per-thread delivery queues). It deadlocked inside CultLib: a load's
delivery reaching a CultNetDatabaseSubscriptionServer observer that needs
_lifecycleGate, while a subscribe's demand handler holding that gate writes
the cache and waits for the delivery's turn.
The cache now owns order as data. Every admitted change takes the next value
of a per-cache in-memory sequence under the gate, published as
CultCacheDocumentChange<T>.Sequence. Delivery is the 544c087/b653f68 rule:
each call publishes its own changes on its own thread after releasing the
gate; nothing waits on another call's delivery. Cross-thread delivery order is
not guaranteed.
Deleted: ticket counter, _delivered, _deliveryGate, Monitor.Wait turns,
per-thread delivery queues, per-ticket catch-all, and the save-order contract
text with its observer-must-not-block rule.
Consumer: a cache-backed CultMesh document handle hands its observed and
reactive mirrors each snapshot's Sequence; ApplyCanonicalSnapshot drops one
not newer than the last applied.
Tests: SequenceIncreasesInAdmissionOrder,
ObserverWritingTheSameCacheDoesNotWaitOnOtherDeliveries,
SubscriptionDemandHandlerWritingCacheDuringDeliveryDoesNotDeadlock,
WatchRecordIgnoresStaleSequence. The last three time out on bcae483.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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