[espnow] Add wake_loop_threadsafe() for low-latency event processing (#11696)

esphome/components/espnow/__init__.py

@@ -1,6 +1,6 @@
 from esphome import automation, core
 import esphome.codegen as cg
-from esphome.components import wifi
+from esphome.components import socket, wifi
 from esphome.components.udp import CONF_ON_RECEIVE
 import esphome.config_validation as cv
 from esphome.const import (
@@ -17,6 +17,7 @@ from esphome.core import CORE, HexInt
 from esphome.types import ConfigType
 
 CODEOWNERS = ["@jesserockz"]
+AUTO_LOAD = ["socket"]
 
 byte_vector = cg.std_vector.template(cg.uint8)
 peer_address_t = cg.std_ns.class_("array").template(cg.uint8, 6)
@@ -120,6 +121,10 @@ async def to_code(config):
     if CORE.using_arduino:
         cg.add_library("WiFi", None)
 
+    # ESP-NOW uses wake_loop_threadsafe() to wake the main loop from ESP-NOW callbacks
+    # This enables low-latency event processing instead of waiting for select() timeout
+    socket.require_wake_loop_threadsafe()
+
     cg.add_define("USE_ESPNOW")
     if wifi_channel := config.get(CONF_CHANNEL):
         cg.add(var.set_wifi_channel(wifi_channel))

esphome/components/espnow/espnow_component.cpp

@@ -4,6 +4,7 @@
 
 #include "espnow_err.h"
 
+#include "esphome/core/application.h"
 #include "esphome/core/defines.h"
 #include "esphome/core/log.h"
 
@@ -97,6 +98,11 @@ void on_send_report(const uint8_t *mac_addr, esp_now_send_status_t status)
   // Push the packet to the queue
   global_esp_now->receive_packet_queue_.push(packet);
   // Push always because we're the only producer and the pool ensures we never exceed queue size
+
+  // Wake main loop immediately to process ESP-NOW send event instead of waiting for select() timeout
+#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
+  App.wake_loop_threadsafe();
+#endif
 }
 
 void on_data_received(const esp_now_recv_info_t *info, const uint8_t *data, int size) {
@@ -114,6 +120,11 @@ void on_data_received(const esp_now_recv_info_t *info, const uint8_t *data, int
   // Push the packet to the queue
   global_esp_now->receive_packet_queue_.push(packet);
   // Push always because we're the only producer and the pool ensures we never exceed queue size
+
+  // Wake main loop immediately to process ESP-NOW receive event instead of waiting for select() timeout
+#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
+  App.wake_loop_threadsafe();
+#endif
 }
 
 ESPNowComponent::ESPNowComponent() { global_esp_now = this; }