After a teleport ACE floods a town's CreateObjects; WorldSession.Tick drained the
ENTIRE inbound queue every frame, each spawn hydrating mesh+textures under _datLock
on the render thread — monopolizing the update loop for ~a minute and starving the
streaming apply, so only the destination landblock loaded and neighbors trickled in
(visible at high render-FPS because update/render are separate Silk.NET callbacks).
Bound the per-frame drain to a ~4ms wall-clock budget once InWorld (handshake uses
the blocking PumpOnce path, never Tick). A time budget self-adapts to the highly
variable per-datagram cost; the tail stays queued (unbounded channel, FIFO) and
drains over the next few frames. Acks are queued per packet BEFORE the heavy handler
(WorldSession.cs:680), so deferring the tail only delays the tail's acks a few frames
— within ACE's tolerance (holtburger defers acks on a flush cadence; verified in
references/holtburger session/send.rs). Budget decision extracted as a pure testable
static (4 unit tests).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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