The single highest-value fix of the TLC pass (deep-read §1): one native
chain-mutation mutex (addon/ChainOps) held across the FULL Execute() of
every chain worker (LoadPreset/LoadVST/LoadNAM/LoadIR/ReplaceIR) and the
synchronous mutators (clearChain/removeProcessor/moveProcessor). Two
overlapping loadPreset calls can no longer interleave clear()/addProcessor()
into a merged-garbage chain — the plugin-vs-plugin fight becomes
last-writer-wins.
chainGeneration (monotonic, bumped under the mutex) is returned in loadPreset
results and exposed as getChainGeneration (new export, snapshot regenerated),
so the audio-effects executor can detect a foreign write invalidated its
stageSlots map and re-sync instead of flipping bypass/params on wrong slots —
the prerequisite for the single-chain-owner ownership track.
Also rides here: LoadPresetWorker's slot-state restore goes through
setSlotState() instead of const_cast (deep-read §9).
The phase-0 storm test flips from expected-fail to a hard gate: 50 iterations
of concurrent loadPreset now always end with exactly one caller's chain.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Snapshot the three public surfaces the audio-engine decomposition must not
change (docs/audio-engine-tlc.md Part IV §4): addon export table, audio-bridge
IPC channels, preload audio/audioEffects API keys. contract-check.test.js
diffs regenerated surfaces against the committed snapshots.
result-shapes.json (golden result key/type shapes) is deferred until the
engine_units harness can run the addon against a null device.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
