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Use relaxed memory ordering for event pending flag

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The flag is just a hint — xQueueReceive with its own internal
synchronization is the source of truth. Relaxed ordering avoids
unnecessary fence cost on ESP targets. Worst case is missing an
event for one loop iteration.
This commit is contained in:
J. Nick Koston
2026-03-29 19:16:03 -10:00
parent 5d2f568565
commit ac2f837c7f
1 changed files with 3 additions and 2 deletions
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esphome/components/wifi/wifi_component_esp_idf.cpp
+3 -2
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@@ -145,7 +145,8 @@ void event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, voi
if (xQueueSend(s_event_queue, &to_send, 0L) != pdPASS) {
delete to_send; // NOLINT(cppcoreguidelines-owning-memory)
} else {
s_event_pending.store(1, std::memory_order_release);
// relaxed: this is just a hint; xQueueReceive is the source of truth
s_event_pending.store(1, std::memory_order_relaxed);
}
}
@@ -734,7 +735,7 @@ const char *get_disconnect_reason_str(uint8_t reason) {
void WiFiComponent::wifi_loop_() {
// Fast path: skip xQueueReceive kernel call when no events are pending.
// The atomic load is much cheaper than entering the FreeRTOS kernel.
if (s_event_pending.load(std::memory_order_acquire) == 0)
if (s_event_pending.load(std::memory_order_relaxed) == 0)
return;
// Clear flag before draining. If a new event arrives between the clear