From bb2991bfdae6de1ec4cf70b8fcfc982215691e76 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Tue, 31 Mar 2026 21:31:41 -1000
Subject: [PATCH] Address review: critical sections for dropped_count_, delete
 copy/move

- Protect dropped_count_ increment and get+reset with
  portENTER_CRITICAL/portEXIT_CRITICAL since std::atomic is unavailable
  on NO_ATOMICS platforms
- Delete copy/move constructors and assignment operators
- Remove volatile qualifier (critical sections provide proper
  synchronization)
---
 esphome/core/freertos_queue.h | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/esphome/core/freertos_queue.h b/esphome/core/freertos_queue.h
index 9ce4fe3543..5778c11797 100644
--- a/esphome/core/freertos_queue.h
+++ b/esphome/core/freertos_queue.h
@@ -28,12 +28,20 @@ template<class T, uint8_t SIZE> class FreeRTOSQueue {
  public:
   FreeRTOSQueue() : dropped_count_(0) { this->handle_ = xQueueCreate(SIZE, sizeof(T *)); }
 
+  // Non-copyable, non-movable — queue handle is not transferable
+  FreeRTOSQueue(const FreeRTOSQueue &) = delete;
+  FreeRTOSQueue &operator=(const FreeRTOSQueue &) = delete;
+  FreeRTOSQueue(FreeRTOSQueue &&) = delete;
+  FreeRTOSQueue &operator=(FreeRTOSQueue &&) = delete;
+
   bool push(T *element) {
     if (element == nullptr || this->handle_ == nullptr)
       return false;
 
     if (xQueueSend(this->handle_, &element, 0) != pdPASS) {
+      portENTER_CRITICAL();
       this->dropped_count_++;
+      portEXIT_CRITICAL();
       return false;
     }
     return true;
@@ -51,14 +59,18 @@ template<class T, uint8_t SIZE> class FreeRTOSQueue {
   }
 
   uint16_t get_and_reset_dropped_count() {
+    portENTER_CRITICAL();
     uint16_t count = this->dropped_count_;
-    if (count == 0)
-      return 0;
     this->dropped_count_ = 0;
+    portEXIT_CRITICAL();
     return count;
   }
 
-  void increment_dropped_count() { this->dropped_count_++; }
+  void increment_dropped_count() {
+    portENTER_CRITICAL();
+    this->dropped_count_++;
+    portEXIT_CRITICAL();
+  }
 
   bool empty() const {
     if (this->handle_ == nullptr)
@@ -80,7 +92,7 @@ template<class T, uint8_t SIZE> class FreeRTOSQueue {
 
  protected:
   QueueHandle_t handle_;
-  volatile uint16_t dropped_count_;
+  uint16_t dropped_count_;
 };
 
 }  // namespace esphome