wasm/shims/context_sleep.cpp: a main-thread nanosleep whose frame stands on a
scheduler context that OWNS the stack arms a mailbox wake and yield_parks that
context instead of suspending the stack in place. It lives in the sleep
primitive rather than in tool_manager.cpp on purpose - KiCad and the wx core
stay untouched (CLAUDE.md's fork rule) and the whole K7 class moves at once,
not just TOOL_MANAGER::RunSynchronousAction's spin loop.
MEASURED AT D-ON, and it is NOT what unblocks Phase D. The four canvas-tool
specs still fail, but the trace now names a different cause: the fatal swap is
old=<libcontext ROOT> new=<tool coroutine> with mouseEventHandlerFunc above it
- a DOM mouse handler entering wasm DIRECTLY on the main stack, bypassing the
tick. So one coroutine is entered two ways: by the tick through the dispatch
context as a STAR TRANSFER, and by DOM handlers as a DIRECT SYMMETRIC SWAP. A
capture written by one path cannot be rewound by the other -> index out of
bounds in doRewind. That is section 7 rule 5 (partial migration is worse than
none) in its purest measured form, and it is why the harness stays green: its
coroutines are only ever entered from one place.
So the next increment is the DOM event entries (mouse/key/wheel/resize must
hand their events to the dispatch context as the tick does), not another park
site. It subsumes the one-root work too: with no dispatch on the main stack,
resolve_root_identity() always answers "the running context".
Landing state: STAR_DISPATCH=0, kicad 139 passed / 1 (pre-existing occ-probe)
= baseline, with the sleep shim in and inert.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LBjomQfKyRa3jBdeAKpmTw
80468e7c5b