no-throw/thread-safe baseline

Author: zekageri

.github/workflows/ci.yml

@@ -8,8 +8,22 @@ on:
   workflow_dispatch:
 
 jobs:
+  source-audit:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Audit production sources
+        run: |
+          if rg -n '\bthrow\b|std::abort\(' src; then
+            echo "Embedded safety audit failed"
+            exit 1
+          fi
+
   build-examples:
     runs-on: ubuntu-latest
+    needs: source-audit
     strategy:
       fail-fast: false
       matrix:
@@ -56,6 +70,7 @@ jobs:
 
   arduino-cli:
     runs-on: ubuntu-latest
+    needs: source-audit
     env:
       ESP32_CORE_VERSION: 3.3.3
       ARDUINO_BOARDS: |

library.json

@@ -36,7 +36,8 @@
   "headers": ["ESPCpuMonitor.h"],
   "build": {
     "flags": [
-      "-std=gnu++17"
+      "-std=gnu++17",
+      "-fno-exceptions"
     ]
   }
 }

src/esp_cpu_monitor/cpu_monitor.cpp

@@ -50,6 +50,22 @@ static float clampUsagePercent(float usage) {
 	return usage;
 }
 
+template <typename Callback, typename... Args>
+static void invokeCpuMonitorCallback(const Callback &callback, Args... args) noexcept {
+	if (!callback) {
+		return;
+	}
+
+#if defined(__cpp_exceptions)
+	try {
+		callback(args...);
+	} catch (...) {
+	}
+#else
+	callback(args...);
+#endif
+}
+
 void ESPCpuMonitor::resetState(const CpuMonitorConfig &cfg) {
 	config_ = cfg;
 	if (!isValidSmoothingMode(config_.smoothingMode)) {
@@ -388,7 +404,7 @@ bool ESPCpuMonitor::sampleNow(CpuUsageSample &out) {
 	bool ready = captureSample(out, callbacks);
 	for (const auto &cb : callbacks) {
 		if (cb) {
-			cb(out);
+			invokeCpuMonitorCallback(cb, out);
 		}
 	}
 	return ready;
@@ -427,7 +443,7 @@ void ESPCpuMonitor::timerCallback(void *arg) {
 	if (self->captureSample(sample, callbacks)) {
 		for (const auto &cb : callbacks) {
 			if (cb) {
-				cb(sample);
+				invokeCpuMonitorCallback(cb, sample);
 			}
 		}
 	}
@@ -482,7 +498,8 @@ bool ESPCpuMonitor::computeSampleLocked(CpuUsageSample &out) {
 					baseline = expectedIdle;
 				}
 			}
-			const float idleRatio = baseline > 0.0f ? static_cast<float>(deltaIdle) / baseline : 0.0f;
+			const float idleRatio =
+			    baseline > 0.0f ? static_cast<float>(deltaIdle) / baseline : 0.0f;
 			const float usage = clampUsagePercent(100.0f * (1.0f - idleRatio));
 			perCoreUsage[i] = usage;
 			avg += usage;
@@ -496,8 +513,7 @@ bool ESPCpuMonitor::computeSampleLocked(CpuUsageSample &out) {
 		calibrationSamplesDone_++;
 		if (calibrationSamplesDone_ >= calibrationSamplesNeeded_) {
 			const float calibrationWindowUs = static_cast<float>(calibrationWindowUs_);
-			const float fallbackWindowUs =
-			    static_cast<float>(config_.sampleIntervalMs) * 1000.0f;
+			const float fallbackWindowUs = static_cast<float>(config_.sampleIntervalMs) * 1000.0f;
 			for (int i = 0; i < portNUM_PROCESSORS; ++i) {
 				idleBaseline_[i] /= static_cast<float>(calibrationSamplesNeeded_);
 				if (idleBaseline_[i] < 1.0f) {

src/esp_cpu_monitor/cpu_monitor_allocator.h

@@ -58,20 +58,12 @@ template <typename T> class CpuMonitorAllocator {
 			return nullptr;
 		}
 		if (n > (std::numeric_limits<std::size_t>::max() / sizeof(T))) {
-#if defined(__cpp_exceptions)
-			throw std::bad_alloc();
-#else
-			std::abort();
-#endif
+			return nullptr;
 		}
 
 		void *memory = cpu_monitor_allocator_detail::allocate(n * sizeof(T), usePSRAMBuffers_);
 		if (memory == nullptr) {
-#if defined(__cpp_exceptions)
-			throw std::bad_alloc();
-#else
-			std::abort();
-#endif
+			return nullptr;
 		}
 		return static_cast<T *>(memory);
 	}

test/test_cpu_monitor/test_cpu_monitor.cpp

@@ -1,7 +1,7 @@
 #include <Arduino.h>
 #include <ESPCpuMonitor.h>
-#include <unity.h>
 #include <cmath>
+#include <unity.h>
 
 namespace {