Safety Checks for UI, fix for cfg exceeding LED limit

wled00/FX_fcn.cpp

@@ -1178,9 +1178,9 @@ void WS2812FX::finalizeInit() {
   // create buses/outputs
   unsigned mem = 0;
   unsigned maxI2S = 0;
-  for (const auto &bus : busConfigs) {
-    unsigned memB = bus.memUsage(Bus::isDigital(bus.type) && !Bus::is2Pin(bus.type) ? digitalCount++ : 0); // does not include DMA/RMT buffer
-    mem += memB;
+  for (auto bus : busConfigs) {
+    bool use_placeholder = false;
+    unsigned busMemUsage = bus.memUsage(Bus::isDigital(bus.type) && !Bus::is2Pin(bus.type) ? digitalCount++ : 0); // does not include DMA/RMT buffer
     // estimate maximum I2S memory usage (only relevant for digital non-2pin busses)
     #if !defined(CONFIG_IDF_TARGET_ESP32C3) && !defined(ESP8266)
       #if defined(CONFIG_IDF_TARGET_ESP32) || defined(CONFIG_IDF_TARGET_ESP32S3)
@@ -1200,13 +1200,14 @@ void WS2812FX::finalizeInit() {
       if (i2sCommonSize > maxI2S) maxI2S = i2sCommonSize;
     }
     #endif
-    if (mem + maxI2S <= MAX_LED_MEMORY) {
-      BusManager::add(bus);
-      DEBUG_PRINTF_P(PSTR("Bus memory: %uB\n"), memB);
-    } else {
-      errorFlag = ERR_NORAM_PX; // alert UI
-      DEBUG_PRINTF_P(PSTR("Out of LED memory! Bus %d (%d) #%u not created."), (int)bus.type, (int)bus.count, digitalCount);
-      break;
+    if (mem + busMemUsage + maxI2S > MAX_LED_MEMORY) {
+      DEBUG_PRINTF_P(PSTR("Bus %d with %d LEDS memory usage exceeds limit\n"), (int)bus.type, bus.count);
+      errorFlag = ERR_NORAM; // alert UI  TODO: make this a distinct error: not enough memory for bus
+      use_placeholder = true;
+    }
+    if (BusManager::add(bus, use_placeholder) != -1) {
+      mem += BusManager::busses.back()->getBusSize();
+      if (Bus::isDigital(bus.type) && !Bus::is2Pin(bus.type) && BusManager::busses.back()->isPlaceholder()) digitalCount--; // remove placeholder from digital count
     }
   }
   DEBUG_PRINTF_P(PSTR("LED buffer size: %uB/%uB\n"), mem + maxI2S, BusManager::memUsage());
@@ -1804,6 +1805,10 @@ Segment& WS2812FX::getSegment(unsigned id) {
 void WS2812FX::resetSegments() {
   _segments.clear();          // destructs all Segment as part of clearing
   _segments.emplace_back(0, isMatrix ? Segment::maxWidth : _length, 0, isMatrix ? Segment::maxHeight : 1);
+  if(_segments.size() == 0) {
+    _segments.emplace_back(); // if out of heap, create a default segment
+    errorFlag = ERR_NORAM_PX;
+  }
   _segments.shrink_to_fit();  // just in case ...
   _mainSegment = 0;
 }
@@ -1825,7 +1830,7 @@ void WS2812FX::makeAutoSegments(bool forceReset) {
 
     for (size_t i = s; i < BusManager::getNumBusses(); i++) {
       const Bus *bus = BusManager::getBus(i);
-      if (!bus || !bus->isOk()) break;
+      if (!bus) break;
 
       segStarts[s] = bus->getStart();
       segStops[s]  = segStarts[s] + bus->getLength();

wled00/bus_manager.cpp

@@ -1121,6 +1121,26 @@ size_t BusHub75Matrix::getPins(uint8_t* pinArray) const {
 #endif
 // ***************************************************************************
 
+BusPlaceholder::BusPlaceholder(const BusConfig &bc) 
+: Bus(bc.type, bc.start, bc.autoWhite, bc.count, bc.reversed, bc.refreshReq)
+, _colorOrder(bc.colorOrder)
+, _skipAmount(bc.skipAmount)
+, _frequency(bc.frequency)
+, _milliAmpsPerLed(bc.milliAmpsPerLed)
+, _milliAmpsMax(bc.milliAmpsMax)
+, _text(bc.text)
+{
+  memcpy(_pins, bc.pins, sizeof(_pins));
+}
+
+size_t BusPlaceholder::getPins(uint8_t* pinArray) const {
+  size_t nPins = Bus::getNumberOfPins(_type);
+  if (pinArray) {
+    for (size_t i = 0; i < nPins; i++) pinArray[i] = _pins[i];
+  }
+  return nPins;
+}
+
 //utility to get the approx. memory usage of a given BusConfig
 size_t BusConfig::memUsage(unsigned nr) const {
   if (Bus::isVirtual(type)) {
@@ -1164,7 +1184,7 @@ size_t BusManager::memUsage() {
   return size + maxI2S;
 }
 
-int BusManager::add(const BusConfig &bc) {
+int BusManager::add(const BusConfig &bc, bool placeholder) {
   DEBUGBUS_PRINTF_P(PSTR("Bus: Adding bus (p:%d v:%d)\n"), getNumBusses(), getNumVirtualBusses());
   unsigned digital = 0;
   unsigned analog  = 0;
@@ -1174,8 +1194,10 @@ int BusManager::add(const BusConfig &bc) {
     if (bus->isDigital() && !bus->is2Pin()) digital++;
     if (bus->is2Pin()) twoPin++;
   }
-  if (digital > WLED_MAX_DIGITAL_CHANNELS || analog > WLED_MAX_ANALOG_CHANNELS) return -1;
-  if (Bus::isVirtual(bc.type)) {
+  if (digital > WLED_MAX_DIGITAL_CHANNELS || analog > WLED_MAX_ANALOG_CHANNELS) placeholder = true; // TODO: add errorFlag here
+  if (placeholder) {
+    busses.push_back(make_unique<BusPlaceholder>(bc));
+  } else if (Bus::isVirtual(bc.type)) {
     busses.push_back(make_unique<BusNetwork>(bc));
 #ifdef WLED_ENABLE_HUB75MATRIX
   } else if (Bus::isHub75(bc.type)) {
@@ -1282,7 +1304,7 @@ void BusManager::on() {
   if (PinManager::getPinOwner(LED_BUILTIN) == PinOwner::BusDigital) {
     for (auto &bus : busses) {
       uint8_t pins[2] = {255,255};
-      if (bus->isDigital() && bus->getPins(pins)) {
+      if (bus->isDigital() && bus->getPins(pins) && bus->isOk()) {
         if (pins[0] == LED_BUILTIN || pins[1] == LED_BUILTIN) {
           BusDigital &b = static_cast<BusDigital&>(*bus);
           b.begin();
@@ -1377,7 +1399,7 @@ void BusManager::initializeABL() {
       _useABL = true; // at least one bus has ABL set
       uint32_t ESPshare = MA_FOR_ESP / numABLbuses; // share of ESP current per ABL bus
       for (auto &bus : busses) {
-        if (bus->isDigital()) {
+        if (bus->isDigital() && bus->isOk()) {
           BusDigital &busd = static_cast<BusDigital&>(*bus);
           uint32_t busLength = busd.getLength();
           uint32_t busDemand = busLength * busd.getLEDCurrent();

wled00/bus_manager.h

@@ -133,7 +133,7 @@ class Bus {
     virtual void     setColorOrder(uint8_t co)                  {}
     virtual uint32_t getPixelColor(unsigned pix) const          { return 0; }
     virtual size_t   getPins(uint8_t* pinArray = nullptr) const { return 0; }
-    virtual uint16_t getLength() const                          { return isOk() ? _len : 0; }
+    virtual uint16_t getLength() const                          { return _len; }
     virtual uint8_t  getColorOrder() const                      { return COL_ORDER_RGB; }
     virtual unsigned skippedLeds() const                        { return 0; }
     virtual uint16_t getFrequency() const                       { return 0U; }
@@ -152,6 +152,7 @@ class Bus {
     inline  bool     isPWM() const                              { return isPWM(_type); }
     inline  bool     isVirtual() const                          { return isVirtual(_type); }
     inline  bool     is16bit() const                            { return is16bit(_type); }
+    virtual bool     isPlaceholder() const                      { return false; }
     inline  bool     mustRefresh() const                        { return mustRefresh(_type); }
     inline  void     setReversed(bool reversed)                 { _reversed = reversed; }
     inline  void     setStart(uint16_t start)                   { _start = start; }
@@ -372,6 +373,39 @@ class BusNetwork : public Bus {
     #endif
 };
 
+// Placeholder for buses that we can't construct due to resource limitations
+// This preserves the configuration so it can be read back to the settings pages
+// Function calls "mimic" the replaced bus, isPlaceholder() can be used to identify a placeholder
+class BusPlaceholder : public Bus {
+  public:
+    BusPlaceholder(const BusConfig &bc);
+
+    // Actual calls are stubbed out
+    void setPixelColor(unsigned pix, uint32_t c) override {};
+    void show() override {};
+
+    // Accessors
+    uint8_t  getColorOrder() const override  { return _colorOrder; }
+    size_t   getPins(uint8_t* pinArray) const override;
+    unsigned skippedLeds() const override    { return _skipAmount; }
+    uint16_t getFrequency() const override   { return _frequency; }
+    uint16_t getLEDCurrent() const override  { return _milliAmpsPerLed; }
+    uint16_t getMaxCurrent() const override  { return _milliAmpsMax; }
+    const String getCustomText() const override { return _text; }
+    bool     isPlaceholder() const override  { return true; }
+
+    size_t   getBusSize() const override   { return sizeof(BusPlaceholder); }
+
+  private:
+    uint8_t _colorOrder;
+    uint8_t _skipAmount;
+    uint8_t _pins[5];
+    uint16_t _frequency;
+    uint8_t _milliAmpsPerLed;
+    uint16_t _milliAmpsMax;
+    String _text;
+};
+
 #ifdef WLED_ENABLE_HUB75MATRIX
 class BusHub75Matrix : public Bus {
   public:
@@ -504,7 +538,7 @@ namespace BusManager {
 
   //do not call this method from system context (network callback)
   void removeAll();
-  int  add(const BusConfig &bc);
+  int  add(const BusConfig &bc, bool placeholder);
 
   void on();
   void off();

wled00/cfg.cpp

@@ -964,7 +964,7 @@ void serializeConfig(JsonObject root) {
   for (size_t s = 0; s < BusManager::getNumBusses(); s++) {
     DEBUG_PRINTF_P(PSTR("Cfg: Saving bus #%u\n"), s);
     const Bus *bus = BusManager::getBus(s);
-    if (!bus || !bus->isOk()) break;
+    if (!bus) break;  // Memory corruption, iterator invalid
     DEBUG_PRINTF_P(PSTR("  (%d-%d, type:%d, CO:%d, rev:%d, skip:%d, AW:%d kHz:%d, mA:%d/%d)\n"),
       (int)bus->getStart(), (int)(bus->getStart()+bus->getLength()),
       (int)(bus->getType() & 0x7F),

wled00/data/index.js

@@ -668,9 +668,20 @@ function parseInfo(i) {
 	if (loc)    name = "(L) " + name;
 	d.title      = name;
 	simplifiedUI = i.simplifiedui;
-	ledCount     = i.leds.count;
+	// safety checks for LED count data to prevent UI crashes
+	if (i.leds && typeof i.leds.count !== 'undefined') {
+		ledCount = i.leds.count;
+	} else {
+		console.warn('No LED count');
+		ledCount = 30; // fallback value
+	}
 	//syncTglRecv   = i.str;
-	maxSeg       = i.leds.maxseg;
+	if (i.leds && typeof i.leds.maxseg !== 'undefined') {
+		maxSeg = i.leds.maxseg;
+	} else {
+		console.warn('No max segment data');
+		maxSeg = 16; // Reasonable fallback for max segments
+	}
 	pmt          = i.fs.pmt;
 	if (pcMode && !i.wifi.ap) gId('edit').classList.remove("hide"); else gId('edit').classList.add("hide");
 	gId('buttonNodes').style.display = lastinfo.ndc > 0 ? null:"none";
@@ -912,12 +923,24 @@ function populateSegments(s)
 		gId(`segr${i}`).classList.add("hide");
 	}
 	if (segCount < 2) {
-		gId(`segd${lSeg}`).classList.add("hide"); // hide delete if only one segment
-		if (parseInt(gId("seg0bri").value)==255) gId(`segp0`).classList.add("hide");
+		// safety check for segment elements to prevent UI crashes
+		const segdElement = gId(`segd${lSeg}`);
+		if (segdElement) segdElement.classList.add("hide"); // hide delete if only one segment
+		const seg0briElement = gId("seg0bri");
+		const segp0Element = gId(`segp0`);
+		if (seg0briElement && segp0Element && parseInt(seg0briElement.value)==255) segp0Element.classList.add("hide");
 		// hide segment controls if there is only one segment in simplified UI
 		if (simplifiedUI) gId("segcont").classList.add("hide");
 	}
-	if (!isM && !noNewSegs && (cfg.comp.seglen?parseInt(gId(`seg${lSeg}s`).value):0)+parseInt(gId(`seg${lSeg}e`).value)<ledCount) gId(`segr${lSeg}`).classList.remove("hide");
+	// safety checks for segment control elements
+	const segSElement = gId(`seg${lSeg}s`);
+	const segEElement = gId(`seg${lSeg}e`);
+	const segrElement = gId(`segr${lSeg}`);
+	if (!isM && !noNewSegs && segSElement && segEElement && segrElement) {
+		const segLen = cfg.comp.seglen ? parseInt(segSElement.value) : 0;
+		const segEnd = parseInt(segEElement.value);
+		if (segLen + segEnd < ledCount) segrElement.classList.remove("hide");
+	}
 	gId('segutil2').style.display = (segCount > 1) ? "block":"none"; // rsbtn parent
 
 	if (Array.isArray(li.maps) && li.maps.length>1) {
@@ -2251,7 +2274,9 @@ function rptSeg(s)
 	var rev = gId(`seg${s}rev`).checked;
 	var mi = gId(`seg${s}mi`).checked;
 	var sel = gId(`seg${s}sel`).checked;
-	var pwr = gId(`seg${s}pwr`).classList.contains('act');
+	// safety check for segment power element to prevent UI crashes
+	const segPwrElement = gId(`seg${s}pwr`);
+	var pwr = segPwrElement ? segPwrElement.classList.contains('act') : false;
 	var obj = {"seg": {"id": s, "n": name, "start": start, "stop": (cfg.comp.seglen?start:0)+stop, "rev": rev, "mi": mi, "on": pwr, "bri": parseInt(gId(`seg${s}bri`).value), "sel": sel}};
 	if (gId(`seg${s}grp`)) {
 		var grp = parseInt(gId(`seg${s}grp`).value);
@@ -2378,7 +2403,13 @@ function setGrp(s, g)
 
 function setSegPwr(s)
 {
-	var pwr = gId(`seg${s}pwr`).classList.contains('act');
+	// safety check for segment power element to prevent UI crashes
+	const segPwrElement = gId(`seg${s}pwr`);
+	if (!segPwrElement) {
+		console.warn('No power elemen');
+		return;
+	}
+	var pwr = segPwrElement.classList.contains('act');
 	var obj = {"seg": {"id": s, "on": !pwr}};
 	requestJson(obj);
 }

wled00/wled.cpp

@@ -39,8 +39,8 @@ void WLED::reset()
 
 void WLED::loop()
 {
-  static uint32_t      lastHeap = UINT32_MAX;
-  static unsigned long heapTime = 0;
+  static uint16_t      heapTime = 0;   // timestamp for heap check
+  static uint8_t       heapDanger = 0; // counter for consecutive low-heap readings
 #ifdef WLED_DEBUG
   static unsigned long lastRun = 0;
   unsigned long        loopMillis = millis();
@@ -169,19 +169,41 @@ void WLED::loop()
     createEditHandler(false);
   }
 
-  // reconnect WiFi to clear stale allocations if heap gets too low
-  if (millis() - heapTime > 15000) {
-    uint32_t heap = getFreeHeapSize();
-    if (heap < MIN_HEAP_SIZE && lastHeap < MIN_HEAP_SIZE) {
-      DEBUG_PRINTF_P(PSTR("Heap too low! %u\n"), heap);
-      forceReconnect = true;
-      strip.resetSegments(); // remove all but one segments from memory
-    } else if (heap < MIN_HEAP_SIZE) {
-      DEBUG_PRINTLN(F("Heap low, purging segments."));
-      strip.purgeSegments();
+   // free memory and reconnect WiFi to clear stale allocations if heap is too low for too long, check once per second
+  if ((uint16_t)(millis() - heapTime) > 1000) {
+    #ifdef ESP8266
+    uint32_t heap = getFreeHeapSize(); // ESP8266 needs ~8k of free heap for UI to work properly
+    #else
+    uint32_t heap = getContiguousFreeHeap(); // ESP32 family needs ~10k of contiguous free heap for UI to work properly
+    #endif
+    if (heap < MIN_HEAP_SIZE) heapDanger++;
+    else heapDanger = 0;
+    switch (heapDanger) {
+      case 15: // 15 consecutive seconds
+        DEBUG_PRINTLN(F("Heap low, purging segments"));
+        strip.purgeSegments();
+        strip.setTransition(0); // disable transitions
+        for (unsigned i = 0; i < strip.getSegmentsNum(); i++) {
+          strip.getSegments()[i].setMode(FX_MODE_STATIC); // set static mode to free effect memory
+        }
+        errorFlag = ERR_NORAM; // alert UI  TODO: make this a distinct error: segment reset
+        break;
+      case 30: // 30 consecutive seconds
+        DEBUG_PRINTLN(F("Heap low, reset segments"));
+        strip.resetSegments(); // remove all but one segments from memory
+        errorFlag = ERR_NORAM; // alert UI  TODO: make this a distinct error: segment reset
+        break;
+      case 45: // 45 consecutive seconds
+        DEBUG_PRINTF_P(PSTR("Heap panic! Reset strip, reset connection\n"));
+        strip.~WS2812FX();      // deallocate strip and all its memory
+        new(&strip) WS2812FX(); // re-create strip object, respecting current memory limits
+        forceReconnect = true;  // in case wifi is broken, make sure UI comes back, set disableForceReconnect = true to avert
+        errorFlag = ERR_NORAM; // alert UI  TODO: make this a distinct error: strip reset
+        break;
+      default:
+        break;
     }
-    lastHeap = heap;
-    heapTime = millis();
+    heapTime = (uint16_t)millis();
   }
 
   //LED settings have been saved, re-init busses

wled00/xml.cpp

@@ -314,7 +314,7 @@ void getSettingsJS(byte subPage, Print& settingsScript)
     unsigned sumMa = 0;
     for (size_t s = 0; s < BusManager::getNumBusses(); s++) {
       const Bus *bus = BusManager::getBus(s);
-      if (!bus || !bus->isOk()) break; // should not happen but for safety
+      if (!bus) break; // should not happen but for safety
       int offset = s < 10 ? '0' : 'A' - 10;
       char lp[4] = "L0"; lp[2] = offset+s; lp[3] = 0; //ascii 0-9 //strip data pin
       char lc[4] = "LC"; lc[2] = offset+s; lc[3] = 0; //strip length