fix: serialize per-pump shutdown + cancel deferred dispatch in turnOffAllMachines

PS calls turnOffAllMachines on every tick once level < stopLevel. Two
ways the pump could re-engage after we shut it down:

1. _delayedCall: a 1% dead-zone keep-alive parked in MGC's deferred
   dispatch fires from the in-flight handleInput's finally block AFTER
   the shutdown completes, dispatching flow + startup to a fresh pump.
   Clear _delayedCall at the top of turnOff.

2. Concurrent shutdown calls on the same pump interrupt each other
   before the sequence can transition past stopping. Track shutdown-
   in-flight per pump and skip if one is already underway.

Together with the rotatingMachine delayedMove-clearing fix, this lets
the level-based hysteresis cycle complete: pumps shut off cleanly at
stopLevel, basin reverses direction, refills to startLevel, repeat.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/specificClass.js

@@ -1421,8 +1421,28 @@ class MachineGroup {
     }
 
     async turnOffAllMachines(){
+        // Cancel any deferred dispatch — turnOff is the latest user intent,
+        // a stale 1% keep-alive must not re-engage a pump after we shut down.
+        this._delayedCall = null;
+        // Per-pump shutdown serialization: PS calls turnOffAllMachines on
+        // every tick (every 2 s) once level < stopLevel. Without this guard,
+        // each new shutdown call hits the still-running prior shutdown's
+        // movement transitions and triggers abortCurrentMovement, which
+        // bounces the pump back to 'operational' before the sequence loop
+        // can reach stopping/coolingdown/idle. Net effect: pump never
+        // actually shuts down. Track shutdown-in-flight per pump and skip
+        // if already underway.
+        if (!this._shutdownInFlight) this._shutdownInFlight = new Set();
         await Promise.all(Object.entries(this.machines).map(async ([machineId, machine]) => {
-            if (this.isMachineActive(machineId)) { await machine.handleInput("parent", "execsequence", "shutdown"); }
+            if (this._shutdownInFlight.has(machineId)) return;
+            if (this.isMachineActive(machineId)) {
+                this._shutdownInFlight.add(machineId);
+                try {
+                    await machine.handleInput("parent", "execsequence", "shutdown");
+                } finally {
+                    this._shutdownInFlight.delete(machineId);
+                }
+            }
         }));
         // Update measurements to zero so the parent (PS) sees the
         // outflow drop immediately — without this the PS keeps the

test/integration/turnoff-deadlock.integration.test.js

@@ -0,0 +1,131 @@
+// Regression: pump A in pumpingstation-complete-example demo got stuck
+// running at minimum flow while basin level dropped past stopLevel and
+// kept dropping all the way to dry-run threshold.
+//
+// Root cause (two parts):
+//
+// 1. rotatingMachine.executeSequence on shutdown went through an
+//    interruptible-abort path that returned the FSM to 'operational',
+//    triggering state.transitionToState's auto-pickup of the queued
+//    delayedMove — re-engaging the pump before the shutdown sequence
+//    could reach stopping/coolingdown/idle. Fix: clear delayedMove at
+//    the top of shutdown/emergencystop sequences.
+//
+// 2. PS calls turnOffAllMachines on every tick (every 2 s) while
+//    level < stopLevel. Each call interrupted the still-running prior
+//    shutdown's transitions, resetting the FSM to 'accelerating'. The
+//    pump bounced accelerating ↔ decelerating forever and the actual
+//    shutdown sequence transitions never ran. Fix: serialize per-pump
+//    shutdown calls in turnOffAllMachines so concurrent invocations
+//    are no-ops while a shutdown is already in flight.
+//
+// This test exercises part 2 — the per-pump serialization at the MGC
+// level — by hammering turnOffAllMachines from a tight loop, mirroring
+// the live tick cadence.
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const MachineGroup = require('../../src/specificClass');
+const Machine = require('../../../rotatingMachine/src/specificClass');
+
+const logCfg = { enabled: false, logLevel: 'error' };
+
+const stateConfig = {
+  general: { logging: logCfg },
+  state: { current: 'idle' },
+  movement: { mode: 'staticspeed', speed: 50, maxSpeed: 100, interval: 10 },
+  // Non-zero shutdown timing so a shutdown takes long enough that a
+  // concurrent turnOff call lands mid-sequence — exactly the live race.
+  time: { starting: 0, warmingup: 0, stopping: 1, coolingdown: 1 },
+};
+
+function machineConfig(id) {
+  return {
+    general: { logging: logCfg, name: id, id, unit: 'm3/h' },
+    functionality: { softwareType: 'machine', role: 'rotationaldevicecontroller' },
+    asset: { category: 'pump', type: 'centrifugal', model: 'hidrostal-H05K-S03R', supplier: 'hidrostal' },
+    mode: {
+      current: 'auto',
+      allowedActions: { auto: ['execsequence', 'execmovement', 'flowmovement', 'statuscheck'] },
+      allowedSources: { auto: ['parent', 'GUI'] },
+    },
+    sequences: {
+      startup:        ['starting', 'warmingup', 'operational'],
+      shutdown:       ['stopping', 'coolingdown', 'idle'],
+      emergencystop:  ['emergencystop', 'off'],
+    },
+  };
+}
+
+function groupConfig() {
+  return {
+    general: { logging: logCfg, name: 'mgc', id: 'mgc' },
+    functionality: { softwareType: 'machinegroup', role: 'groupcontroller', positionVsParent: 'atEquipment' },
+    scaling: { current: 'normalized' },
+    mode:    { current: 'optimalcontrol' },
+  };
+}
+
+function buildGroup() {
+  const mgc = new MachineGroup(groupConfig());
+  const ids = ['pump_a', 'pump_b', 'pump_c'];
+  const pumps = ids.map(id => new Machine(machineConfig(id), stateConfig));
+  for (const m of pumps) {
+    m.updateMeasuredPressure(0,    'upstream',   { timestamp: Date.now(), unit: 'mbar', childName: 'up', childId: `up-${m.config.general.id}` });
+    m.updateMeasuredPressure(1100, 'downstream', { timestamp: Date.now(), unit: 'mbar', childName: 'dn', childId: `dn-${m.config.general.id}` });
+    mgc.childRegistrationUtils.registerChild(m, 'downstream');
+  }
+  mgc.calcAbsoluteTotals();
+  mgc.calcDynamicTotals();
+  return { mgc, pumps };
+}
+
+const sleep = (ms) => new Promise(r => setTimeout(r, ms));
+
+test('repeated turnOffAllMachines reaches idle (serializes concurrent shutdowns)', async () => {
+  const { mgc, pumps } = buildGroup();
+  const pumpA = pumps[0];
+
+  // Start pump A and queue a delayedMove the way MGC's optimalControl
+  // would when PS sends a 1% dead-zone keep-alive.
+  await pumpA.handleInput('parent', 'execsequence', 'startup');
+  assert.equal(pumpA.state.getCurrentState(), 'operational');
+  pumpA.setpoint(80);                  // start a slow move (not awaited)
+  await sleep(50);
+  assert.equal(pumpA.state.getCurrentState(), 'accelerating');
+  pumpA.state.delayedMove = 75;
+
+  // Mimic PS's tick loop: fire turnOffAllMachines on a tight cadence
+  // without awaiting. Without the per-pump serialization in
+  // turnOffAllMachines, each call hits the still-running prior shutdown
+  // and bounces the pump back to accelerating — the live deadlock.
+  const ticks = [];
+  for (let i = 0; i < 6; i++) {
+    ticks.push(mgc.turnOffAllMachines());
+    await sleep(80);                   // half the realtime tick — tighter race
+  }
+  await Promise.all(ticks);
+  // Allow the (single) in-flight shutdown to finish its 1+1 s timed
+  // transitions through stopping → coolingdown → idle.
+  await sleep(2500);
+
+  assert.equal(pumpA.state.getCurrentState(), 'idle',
+    `pump must reach idle under repeated turnOff calls; got ${pumpA.state.getCurrentState()} (delayedMove=${pumpA.state.delayedMove})`);
+  assert.equal(pumpA.state.delayedMove, null,
+    'delayedMove must be cleared after shutdown');
+});
+
+test('turnOffAllMachines clears MGC._delayedCall to cancel any deferred dispatch', async () => {
+  // PS sends a 1% keep-alive while MGC is mid-dispatch. MGC parks it in
+  // _delayedCall. PS then crosses stopLevel and calls turnOffAllMachines.
+  // Without clearing _delayedCall, MGC's finally block fires the parked
+  // 1% call AFTER the shutdown — re-engaging the pump.
+  const { mgc } = buildGroup();
+  mgc._delayedCall = { source: 'parent', demand: 1, powerCap: Infinity, priorityList: null };
+
+  await mgc.turnOffAllMachines();
+
+  assert.equal(mgc._delayedCall, null,
+    'turnOff must cancel any deferred dispatch so it cannot re-engage pumps post-shutdown');
+});