Stop setting USE_SOCKET_SELECT_SUPPORT on fast-select platforms

USE_SOCKET_SELECT_SUPPORT now exclusively means 'host select() fallback'.
ESP32/LibreTiny use USE_LWIP_FAST_SELECT instead. This eliminates
all 'USE_SOCKET_SELECT_SUPPORT && !USE_LWIP_FAST_SELECT' guards.

esphome/components/socket/__init__.py

@@ -161,16 +161,16 @@ async def to_code(config):
         cg.add_define("USE_SOCKET_IMPL_LWIP_TCP")
     elif impl == IMPLEMENTATION_LWIP_SOCKETS:
         cg.add_define("USE_SOCKET_IMPL_LWIP_SOCKETS")
-        cg.add_define("USE_SOCKET_SELECT_SUPPORT")
     elif impl == IMPLEMENTATION_BSD_SOCKETS:
         cg.add_define("USE_SOCKET_IMPL_BSD_SOCKETS")
-        cg.add_define("USE_SOCKET_SELECT_SUPPORT")
     # ESP32 and LibreTiny both have LwIP >= 2.1.3 with lwip_socket_dbg_get_socket()
     # and FreeRTOS task notifications — enable fast select to bypass lwip_select().
     # Only when not using lwip_tcp, which does not provide select() support.
     if (CORE.is_esp32 or CORE.is_libretiny) and impl != IMPLEMENTATION_LWIP_TCP:
         cg.add_build_flag("-DUSE_LWIP_FAST_SELECT")
     elif impl != IMPLEMENTATION_LWIP_TCP:
+        # Host platform: uses select() syscall for socket monitoring
+        cg.add_define("USE_SOCKET_SELECT_SUPPORT")
         # Platforms with select() but without fast select (host) need a UDP
         # loopback socket for wake_loop_threadsafe().
         consume_sockets(1, "socket.wake_loop_threadsafe", SocketType.UDP)({})

esphome/components/socket/socket.cpp

@@ -8,7 +8,7 @@
 
 namespace esphome::socket {
 
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
 // Shared ready() implementation for fd-based socket implementations (BSD and LWIP sockets).
 // Checks if the Application's select() loop has marked this fd as ready.
 bool socket_ready_fd(int fd, bool loop_monitored) { return !loop_monitored || App.is_socket_ready_(fd); }

esphome/core/application.cpp

@@ -128,13 +128,13 @@ void Application::setup() {
   clear_setup_priority_overrides();
 #endif
 
-#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_LWIP_FAST_SELECT
   // Initialize fast select: saves main loop task handle for xTaskNotifyGive wake.
   // The fast path (rcvevent reads + ulTaskNotifyTake) is used unconditionally
   // when USE_LWIP_FAST_SELECT is enabled (ESP32 and LibreTiny).
   esphome_lwip_fast_select_init();
 #endif
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   // Set up wake socket for waking main loop from tasks (platforms without fast select only)
   this->setup_wake_loop_threadsafe_();
 #endif
@@ -547,7 +547,7 @@ void Application::unregister_socket_fd(int fd) {
 #endif
 
 // Only the select() fallback path remains in the .cpp — all other paths are inlined in application.h
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
 void Application::yield_with_select_(uint32_t delay_ms) {
   // Fallback select() path (host platform and any future platforms without fast select).
   if (!this->socket_fds_.empty()) [[likely]] {
@@ -597,7 +597,7 @@ void Application::yield_with_select_(uint32_t delay_ms) {
   // No sockets registered or select() failed - use regular delay
   delay(delay_ms);
 }
-#endif  // defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#endif  // USE_SOCKET_SELECT_SUPPORT
 
 // App storage — asm label shares the linker symbol with "extern Application App".
 // char[] is trivially destructible, so no __cxa_atexit or destructor chain is emitted.
@@ -620,7 +620,7 @@ alignas(Application) char app_storage[sizeof(Application)] asm(
 
 // Host platform wake_loop_threadsafe() and setup — needs wake_socket_fd_
 // ESP32/LibreTiny/ESP8266/RP2040 implementations are in wake.cpp
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
 
 void Application::setup_wake_loop_threadsafe_() {
   // Create UDP socket for wake notifications

esphome/core/application.h

@@ -25,20 +25,9 @@
 #endif
 
 #ifdef USE_SOCKET_SELECT_SUPPORT
-#ifdef USE_LWIP_FAST_SELECT
-#include "esphome/core/lwip_fast_select.h"
-#ifdef USE_ESP32
-#include <freertos/FreeRTOS.h>
-#include <freertos/task.h>
-#else
-#include <FreeRTOS.h>
-#include <task.h>
-#endif
-#else
 #include <sys/select.h>
 #include <lwip/sockets.h>
 #endif
-#endif  // USE_SOCKET_SELECT_SUPPORT
 #ifdef USE_RUNTIME_STATS
 #include "esphome/components/runtime_stats/runtime_stats.h"
 #endif
@@ -565,7 +554,7 @@ class Application {
 
  protected:
   friend Component;
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   friend bool socket::socket_ready_fd(int fd, bool loop_monitored);
 #endif
 #ifdef USE_RUNTIME_STATS
@@ -573,11 +562,11 @@ class Application {
 #endif
   friend void ::setup();
   friend void ::original_setup();
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   friend void wake_loop_threadsafe();  // Host platform accesses wake_socket_fd_
 #endif
 
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   bool is_socket_ready_(int fd) const { return FD_ISSET(fd, &this->read_fds_); }
 #endif
 
@@ -622,14 +611,14 @@ class Application {
   void feed_wdt_arch_();
 
   /// Perform a delay while also monitoring socket file descriptors for readiness
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   // select() fallback path is too complex to inline (host platform)
   void yield_with_select_(uint32_t delay_ms);
 #else
   inline void ESPHOME_ALWAYS_INLINE yield_with_select_(uint32_t delay_ms);
 #endif
 
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   void setup_wake_loop_threadsafe_();       // Create wake notification socket
   inline void drain_wake_notifications_();  // Read pending wake notifications in main loop (hot path - inlined)
 #endif
@@ -663,9 +652,7 @@ class Application {
   std::vector<int> socket_fds_;  // Vector of all monitored socket file descriptors
 #endif
 #ifdef USE_SOCKET_SELECT_SUPPORT
-#if !defined(USE_LWIP_FAST_SELECT)
   int wake_socket_fd_{-1};  // Shared wake notification socket for waking main loop from tasks
-#endif
 #endif
 
   // StringRef members (8 bytes each: pointer + size)
@@ -676,7 +663,7 @@ class Application {
   uint32_t last_loop_{0};
   uint32_t loop_component_start_time_{0};
 
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   int max_fd_{-1};  // Highest file descriptor number for select()
 #endif
 
@@ -692,11 +679,11 @@ class Application {
   bool in_loop_{false};
   volatile bool has_pending_enable_loop_requests_{false};
 
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   bool socket_fds_changed_{false};  // Flag to rebuild base_read_fds_ when socket_fds_ changes
 #endif
 
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   // Variable-sized members (not needed with fast select — is_socket_ready_ reads rcvevent directly)
   fd_set read_fds_{};       // Working fd_set: populated by select()
   fd_set base_read_fds_{};  // Cached fd_set rebuilt only when socket_fds_ changes
@@ -789,7 +776,7 @@ class Application {
 /// Global storage of Application pointer - only one Application can exist.
 extern Application App;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
 // Inline implementations for hot-path functions
 // drain_wake_notifications_() is called on every loop iteration
 
@@ -811,10 +798,10 @@ inline void Application::drain_wake_notifications_() {
     }
   }
 }
-#endif  // defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#endif  // USE_SOCKET_SELECT_SUPPORT
 
 inline void ESPHOME_ALWAYS_INLINE Application::before_loop_tasks_(uint32_t loop_start_time) {
-#if defined(USE_SOCKET_SELECT_SUPPORT) && !defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_SOCKET_SELECT_SUPPORT
   // Drain wake notifications first to clear socket for next wake
   this->drain_wake_notifications_();
 #endif
@@ -905,9 +892,9 @@ inline void ESPHOME_ALWAYS_INLINE Application::loop() {
 }
 
 // Inline yield_with_select_ for all paths except the select() fallback
-#if !defined(USE_SOCKET_SELECT_SUPPORT) || defined(USE_LWIP_FAST_SELECT)
+#ifndef USE_SOCKET_SELECT_SUPPORT
 inline void ESPHOME_ALWAYS_INLINE Application::yield_with_select_(uint32_t delay_ms) {
-#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_LWIP_FAST_SELECT)
+#ifdef USE_LWIP_FAST_SELECT
   // Fast path (ESP32/LibreTiny): reads rcvevent directly from cached lwip_sock pointers.
   // Safe because this runs on the main loop which owns socket lifetime (create, read, close).
   if (delay_ms == 0) [[unlikely]] {
@@ -934,6 +921,6 @@ inline void ESPHOME_ALWAYS_INLINE Application::yield_with_select_(uint32_t delay
   esphome::wakeable_delay(delay_ms);
 #endif
 }
-#endif  // !defined(USE_SOCKET_SELECT_SUPPORT) || defined(USE_LWIP_FAST_SELECT)
+#endif  // !USE_SOCKET_SELECT_SUPPORT
 
 }  // namespace esphome

esphome/core/defines.h

@@ -251,7 +251,6 @@
 #define USE_SENDSPIN
 #define USE_SENDSPIN_PORT 8928  // NOLINT
 #define USE_SOCKET_IMPL_BSD_SOCKETS
-#define USE_SOCKET_SELECT_SUPPORT
 #define USE_LWIP_FAST_SELECT
 
 #define USE_SPEAKER
@@ -377,7 +376,6 @@
 #ifdef USE_LIBRETINY
 #define USE_CAPTIVE_PORTAL
 #define USE_SOCKET_IMPL_LWIP_SOCKETS
-#define USE_SOCKET_SELECT_SUPPORT
 #define USE_LWIP_FAST_SELECT
 #define USE_WEBSERVER
 #define USE_WEBSERVER_AUTH