Running a multiplexed 4-digit 7-segment clock on ESP32/QEMU froze the
browser for minutes after Run — evaluate probes waited 40-90 s, and before
the first fixes the sim WebSocket eventually died (code 1006) with the page
never recovering. CPU-profiled on staging; four compounding per-GPIO-edge
costs, in profile order:
updateComponentState minted a new components array per edge
------------------------------------------------------------
The store setter rebuilt `components` (and one properties object) on EVERY
edge even when the state didn't change. The breadboard is direct-wired to
13 board pins, so segment toggles produced thousands of store sets per
second; every subscriber re-rendered each time, and the canvas subscription
effect (deps: [components, ...]) re-subscribed all pin listeners in a loop.
Now a no-op guard returns prevState unchanged, and breadboards are treated
as self-managed (they have no visual on/off state to echo).
CompilationConsole re-rendered every log line per editor render
----------------------------------------------------------------
The post-compile console holds hundreds of lines; each render called
Date.toLocaleTimeString per line (~0.2 ms each — it builds a fresh Intl
formatter every call). Profile: 162 s of self time in LogLine over a 337 s
window, in ~150 ms tasks. LogLine is now memoized (entries are immutable),
timestamps go through one shared Intl.DateTimeFormat, and the console
itself is React.memo'd against parent re-renders.
Per-edge full SPICE re-solves
------------------------------
PinManager requested a FULL netlist rebuild+solve on every 'mcu' edge.
Now only the edge that newly classifies a pin as MCU-output triggers the
rebuild (that's what emits the pin's V-source); steady-state updates flow
through connectMcuEdgesToService's per-pin coalesced alterSource path.
The start.ts resolve hook is trailing-throttled (33 ms) for the other
per-edge callers (RP2040, custom chips), the service's pending-edge queue
drains on a 33 ms gap timer instead of replaying back-to-back, and new
edges arriving inside the gap queue instead of soloing a solve.
STM32 / Pi reverse pin-name mappings added to connectMcuEdgesToService so
those boards keep fine-grained updates now that the full-tick storm is
gone (PA0/PC13-style and GPIO-style names never matched before).
wokwi-7segment re-rendered per segment write
---------------------------------------------
element.values now flushes at most every 8 ms per display (trailing write
guaranteed), instead of re-rendering the 32-shape SVG per edge.
Also: CLN (colon) pin support for 7-segment clock faces — wired CLN now
drives colon/colonValue in both the attachEvents path and the QEMU
onPinStateChange path; it was silently ignored, so clock colons never lit.
Verified on staging with the failing project: main-thread probes drop from
40-90 s waits (324 long tasks, 52.6 s blocked in 150 s) to 5-11 ms
(2 long tasks, 179 ms), display shows 12:00 with the colon blinking at
1 Hz from the first seconds after Run.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Two related bugs that surfaced as "Vitest worker exited unexpectedly /
Timeout terminating forks worker" on the circuit-simulation-service
test file.
Bug 1 — tick() recursively re-schedules itself in its finally block.
After afterEach disposes the scheduler via __resetMixedModeScheduler(),
those re-scheduled ticks throw "call loadCircuit first", get caught by
the console.warn, and the finally schedules ANOTHER tick. Infinite
Promise loop survives until the worker OOMs.
Fix: add CircuitSimulationService.stop() that flips a `stopped` flag
short-circuiting tick() + handleMcuEdge(). The test harness now
tracks each started service in _activeServices and calls stop() in
afterEach alongside the existing unsubscribe sweep.
Bug 2 — when an MCU edge fires on a pin that's NOT wired into any net
(buildNetlist skips it because netLookup returns null), handleMcuEdge
sees hasSource=false, self-heals by queueing the edge + tick(). The
rebuild still doesn't emit the V-source (no wire), so tick.finally
replays the edge → self-heal again → tick again → infinite loop AT
RUNTIME, not just in tests. A user toggling a digital pin without a
wire freezes the whole circuit simulation.
Fix: in tick.finally's pendingMcuEdges replay loop, check whether
the rebuilt netlist now contains a V-source for each pending edge's
pin. If not, drop the edge silently — a future canvas tick triggered
by adding the wire will pick it up via the normal subscription path.
Also fix the "coalesces an edge with an in-flight full solve" test
fixture: simpleBoardWithBoard leaves pin 9 unwired, so V_uno_9 was
never emitted and the test was racing the (now-bounded) self-heal
rebuild. Replaced with an inline fixture wiring pin 9 → resistor →
GND, mirroring the wired fixture used by the alter+republish test
right above it.
Full vitest --shard 1/2 + 2/2 pass cleanly (1886 tests, 22-29s per
shard) with no worker-exit warnings.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Two CI failures landed together on master after PR #194 merged:
1. **components-metadata.json stale.** The `power-supply` thumbnail
in scripts/component-overrides.json was updated (grey placeholder
→ branded PSU SVG with voltage/current labels) but the generated
JSON wasn't regenerated. The pre-merge check
`git diff --quiet frontend/public/components-metadata.json` now
fails on master. Fix: `cd frontend && npm run generate:metadata`,
commit the result.
2. **Frontend Tests > test (20/22): vitest worker hang.**
`circuit-simulation-service.test.ts` had been calling
`service.start()` in ~10 tests without storing the returned
unsubscribe handle. Each call subscribes the service to the
simStore; the listener captures the service + scheduler in
its closure. After all tests complete, vitest's forks pool
tries to terminate the worker but the still-active listeners
keep the event loop pinned, producing:
"Worker exited unexpectedly / Timeout terminating forks worker"
All assertions actually pass — only the worker shutdown hangs.
Fix: introduce a `startTracked(service)` helper that records
the unsubscribe in a module-level array, plus an `afterEach`
that drains the array. `__resetMixedModeScheduler()` still runs
after to dispose the scheduler singleton. Replaced all 9 raw
`service.start()` callsites.
Both are independent of any production code change. The fix is
test/scaffolding only.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
CircuitSimulationService.handleMcuEdge(boardId, pinName, state, vcc)
runs the WASM alter + .op + extract path instead of rebuilding the
netlist. Cached `loadedContext` lets `publishFromLastResult` shape an
ElectricalSnapshot without re-running buildInputFromStore.
Coalesces with the canvas-change tick:
- If a full solve is in flight: edge is queued and replayed after
(so the netlist matches when alter runs).
- Last-edge-wins per pin: edges overwrite the same field, so a
10kHz toggle collapses to whatever was last seen at flush time.
connectMcuEdgesToService.ts wires PinManager.onPinChange events to
the service:
- Subscribes to every Arduino-pin slot (0..63) per board. Per-pin
listeners are no-cost when the pin never fires.
- Coalesces edges per pin in a 16 ms window before calling
handleMcuEdge (60 fps cap, well below per-solve cost of 5-15 ms).
- Re-subscribes when boards change (PinManager instances are
recreated by loadHex / setActiveBoard).
MixedModeSchedulerPort gains onMcuPinChange in the port interface
(was already on the singleton but missing from the contract).
3 new service tests cover:
- initial full solve + alter + republish on edge
- coalescing edges with in-flight full solves
- handleMcuEdge kicks a full tick when no circuit is loaded
11 service tests + 90-test regression suite pass. tsc clean.
Next: E — convergence helpers (.options gmin, op-amp retry) so the
LM358 subckt can finally be enabled in componentToSpice.ts.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The service is the single owner of the simulation loop. Replaces
the trio of wireElectricalSolver + connectLegacySolverToMixedMode +
connectMixedModeSchedulerToStore once G* lands.
Architecture:
- Depends on PORTS only — SimulatorStorePort, ElectricalStorePort,
MixedModeSchedulerPort. Zero coupling to useSimulatorStore /
useElectricalStore / WASM. Easy to test with fakes (and that's
what circuit-simulation-service.test.ts does).
- Single tick(): build netlist → load → solve → extract → publish.
Coalesces concurrent triggers so rapid store changes collapse to
one trailing solve.
- Domain ElectricalSnapshot type covers nodeVoltages + branchCurrents
+ pinNetMap + timeWaveforms + analysisMode + warnings. Shape
matches what the 12 existing useElectricalStore consumers read.
NetlistBuilder extension: BuildNetlistResult now reports `nets`
(every non-ground SPICE net) and `voltageSources` (every V card the
builder emitted). The service uses these to construct the full
vectorsOfInterest list — every node voltage + every branch current
— so the solver returns the data the legacy consumers want.
Scheduler addition: `setExtraVectorsOfInterest(vectors)` lets the
orchestrator add to the per-pin set. Branch currents (i(v_*))
flow through this hook.
8 service tests cover initial solve, branch current extraction,
re-solve on store change, no-spurious-solve, coalescing, .tran
waveforms, warnings forwarding, error-tolerance.
Next: C1+C2 — extract ADC injection / waveform replay into a
solver-agnostic module that just subscribes to useElectricalStore.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
David Montero Crespo