Make defer FIFO

esphome/core/scheduler.cpp

@@ -73,8 +73,6 @@ void HOT Scheduler::set_timer_common_(Component *component, SchedulerItem::Type
   if (delay == SCHEDULER_DONT_RUN)
     return;
 
-  const auto now = this->millis_();
-
   // Create and populate the scheduler item
   auto item = make_unique<SchedulerItem>();
   item->component = component;
@@ -83,6 +81,16 @@ void HOT Scheduler::set_timer_common_(Component *component, SchedulerItem::Type
   item->callback = std::move(func);
   item->remove = false;
 
+  // Special handling for defer() (delay = 0, type = TIMEOUT)
+  if (delay == 0 && type == SchedulerItem::TIMEOUT) {
+    // Put in defer queue for guaranteed FIFO execution
+    LockGuard guard{this->lock_};
+    this->defer_queue_.push_back(std::move(item));
+    return;
+  }
+
+  const auto now = this->millis_();
+
   // Type-specific setup
   if (type == SchedulerItem::INTERVAL) {
     item->interval = delay;
@@ -209,6 +217,28 @@ optional<uint32_t> HOT Scheduler::next_schedule_in() {
   return item->next_execution_ - now;
 }
 void HOT Scheduler::call() {
+  // Process defer queue first to guarantee FIFO execution order for deferred items.
+  // Previously, defer() used the heap which gave undefined order for equal timestamps,
+  // causing race conditions on multi-core systems (ESP32, RP2040, BK7200).
+  // With the defer queue:
+  // - Deferred items (delay=0) go directly to defer_queue_ in set_timer_common_
+  // - Items execute in exact order they were deferred (FIFO guarantee)
+  // - No deferred items exist in to_add_, so processing order doesn't affect correctness
+  while (!this->defer_queue_.empty()) {
+    std::unique_ptr<SchedulerItem> item;
+    {
+      LockGuard guard{this->lock_};
+      if (this->defer_queue_.empty())  // Double-check with lock held
+        break;
+      item = std::move(this->defer_queue_.front());
+      this->defer_queue_.pop_front();
+    }
+    // Skip if item was marked for removal or component failed
+    if (!this->should_skip_item_(item.get())) {
+      this->execute_item_(item.get());
+    }
+  }
+
   const auto now = this->millis_();
   this->process_to_add();
 
@@ -294,13 +324,7 @@ void HOT Scheduler::call() {
       // Warning: During callback(), a lot of stuff can happen, including:
       //  - timeouts/intervals get added, potentially invalidating vector pointers
       //  - timeouts/intervals get cancelled
-      {
-        uint32_t now_ms = millis();
-        WarnIfComponentBlockingGuard guard{item->component, now_ms};
-        item->callback();
-        // Call finish to ensure blocking time is properly calculated and reported
-        guard.finish();
-      }
+      this->execute_item_(item.get());
     }
 
     {
@@ -364,6 +388,26 @@ void HOT Scheduler::push_(std::unique_ptr<Scheduler::SchedulerItem> item) {
   LockGuard guard{this->lock_};
   this->to_add_.push_back(std::move(item));
 }
+// Helper function to check if item matches criteria for cancellation
+bool HOT Scheduler::matches_item_(const std::unique_ptr<SchedulerItem> &item, Component *component,
+                                  const char *name_cstr, SchedulerItem::Type type) {
+  if (item->component != component || item->type != type || item->remove) {
+    return false;
+  }
+  const char *item_name = item->get_name();
+  return item_name != nullptr && strcmp(name_cstr, item_name) == 0;
+}
+
+// Helper to execute a scheduler item
+void HOT Scheduler::execute_item_(SchedulerItem *item) {
+  App.set_current_component(item->component);
+
+  uint32_t now_ms = millis();
+  WarnIfComponentBlockingGuard guard{item->component, now_ms};
+  item->callback();
+  guard.finish();
+}
+
 // Common implementation for cancel operations
 bool HOT Scheduler::cancel_item_common_(Component *component, bool is_static_string, const void *name_ptr,
                                         SchedulerItem::Type type) {
@@ -379,19 +423,25 @@ bool HOT Scheduler::cancel_item_common_(Component *component, bool is_static_str
   LockGuard guard{this->lock_};
   bool ret = false;
 
-  for (auto &it : this->items_) {
-    const char *item_name = it->get_name();
-    if (it->component == component && item_name != nullptr && strcmp(name_cstr, item_name) == 0 && it->type == type &&
-        !it->remove) {
-      to_remove_++;
-      it->remove = true;
+  // Check all containers for matching items
+  for (auto &item : this->defer_queue_) {
+    if (this->matches_item_(item, component, name_cstr, type)) {
+      item->remove = true;
       ret = true;
     }
   }
-  for (auto &it : this->to_add_) {
-    const char *item_name = it->get_name();
-    if (it->component == component && item_name != nullptr && strcmp(name_cstr, item_name) == 0 && it->type == type) {
-      it->remove = true;
+
+  for (auto &item : this->items_) {
+    if (this->matches_item_(item, component, name_cstr, type)) {
+      item->remove = true;
+      ret = true;
+      this->to_remove_++;  // Only track removals for heap items
+    }
+  }
+
+  for (auto &item : this->to_add_) {
+    if (this->matches_item_(item, component, name_cstr, type)) {
+      item->remove = true;
       ret = true;
     }
   }

esphome/core/scheduler.h

@@ -2,6 +2,7 @@
 
 #include <vector>
 #include <memory>
+#include <deque>
 
 #include "esphome/core/component.h"
 #include "esphome/core/helpers.h"
@@ -145,6 +146,18 @@ class Scheduler {
   bool cancel_item_(Component *component, const std::string &name, SchedulerItem::Type type);
   bool cancel_item_(Component *component, const char *name, SchedulerItem::Type type);
 
+  // Helper functions for cancel operations
+  bool matches_item_(const std::unique_ptr<SchedulerItem> &item, Component *component, const char *name_cstr,
+                     SchedulerItem::Type type);
+
+  // Helper to execute a scheduler item
+  void execute_item_(SchedulerItem *item);
+
+  // Helper to check if item should be skipped
+  bool should_skip_item_(const SchedulerItem *item) const {
+    return item->remove || (item->component != nullptr && item->component->is_failed());
+  }
+
   bool empty_() {
     this->cleanup_();
     return this->items_.empty();
@@ -153,6 +166,7 @@ class Scheduler {
   Mutex lock_;
   std::vector<std::unique_ptr<SchedulerItem>> items_;
   std::vector<std::unique_ptr<SchedulerItem>> to_add_;
+  std::deque<std::unique_ptr<SchedulerItem>> defer_queue_;  // FIFO queue for defer() calls
   uint32_t last_millis_{0};
   uint16_t millis_major_{0};
   uint32_t to_remove_{0};