[core][esp32_ble] Add wake_loop_threadsafe() helper for background thread wakeups

esphome/codegen.py

@@ -51,6 +51,7 @@ from esphome.cpp_helpers import (  # noqa: F401
     past_safe_mode,
     register_component,
     register_parented,
+    require_wake_loop_threadsafe,
 )
 from esphome.cpp_types import (  # noqa: F401
     NAN,

esphome/components/esp32_ble/__init__.py

@@ -7,7 +7,6 @@ from typing import Any
 
 from esphome import automation
 import esphome.codegen as cg
-from esphome.components import socket
 from esphome.components.esp32 import add_idf_sdkconfig_option, const, get_esp32_variant
 import esphome.config_validation as cv
 from esphome.const import (
@@ -482,13 +481,10 @@ async def to_code(config):
         cg.add(var.set_name(name))
     await cg.register_component(var, config)
 
-    # BLE uses 1 UDP socket for event notification to wake up main loop from select()
+    # BLE uses the core wake_loop_threadsafe() mechanism to wake the main loop from BLE tasks
     # This enables low-latency (~12μs) BLE event processing instead of waiting for
-    # select() timeout (0-16ms). The socket is created in ble_setup_() and used to
+    # select() timeout (0-16ms). The wake socket is shared across all components.
-    # wake lwip_select() when BLE events arrive from the BLE thread.
+    cg.require_wake_loop_threadsafe()
-    # Note: Called during config generation, socket is created at runtime. In practice,
-    # always used since esp32_ble only runs on ESP32 which always has USE_SOCKET_SELECT_SUPPORT.
-    socket.consume_sockets(1, "esp32_ble")(config)
 
     # Define max connections for use in C++ code (e.g., ble_server.h)
     max_connections = config.get(CONF_MAX_CONNECTIONS, DEFAULT_MAX_CONNECTIONS)

esphome/components/esp32_ble/ble.cpp

@@ -297,20 +297,14 @@ bool ESP32BLE::ble_setup_() {
   // BLE takes some time to be fully set up, 200ms should be more than enough
   delay(200);  // NOLINT
 
-  // Set up notification socket to wake main loop for BLE events
+  // Wake mechanism is set up by core Application class (wake_loop_threadsafe)
-  // This enables low-latency (~12μs) event processing instead of waiting for select() timeout
+  // BLE tasks will call App.wake_loop_threadsafe() to wake main loop when events arrive
-#ifdef USE_SOCKET_SELECT_SUPPORT
-  this->setup_event_notification_();
-#endif
 
   return true;
 }
 
 bool ESP32BLE::ble_dismantle_() {
-  // Clean up notification socket first before dismantling BLE stack
+  // No socket cleanup needed - wake socket is managed by core Application
-#ifdef USE_SOCKET_SELECT_SUPPORT
-  this->cleanup_event_notification_();
-#endif
 
   esp_err_t err = esp_bluedroid_disable();
   if (err != ESP_OK) {
@@ -409,12 +403,6 @@ void ESP32BLE::loop() {
       break;
   }
 
-#ifdef USE_SOCKET_SELECT_SUPPORT
-  // Drain any notification socket events first
-  // This clears the socket so it doesn't stay "ready" in subsequent select() calls
-  this->drain_event_notifications_();
-#endif
-
   BLEEvent *ble_event = this->ble_events_.pop();
   while (ble_event != nullptr) {
     switch (ble_event->type_) {
@@ -589,8 +577,8 @@ void ESP32BLE::gap_event_handler(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_pa
     GAP_SECURITY_EVENTS:
       enqueue_ble_event(event, param);
       // Wake up main loop to process security event immediately
-#ifdef USE_SOCKET_SELECT_SUPPORT
+#ifdef USE_WAKE_LOOP_THREADSAFE
-      global_ble->notify_main_loop_();
+      App.wake_loop_threadsafe();
 #endif
       return;
 
@@ -612,8 +600,8 @@ void ESP32BLE::gatts_event_handler(esp_gatts_cb_event_t event, esp_gatt_if_t gat
                                    esp_ble_gatts_cb_param_t *param) {
   enqueue_ble_event(event, gatts_if, param);
   // Wake up main loop to process GATT event immediately
-#ifdef USE_SOCKET_SELECT_SUPPORT
+#ifdef USE_WAKE_LOOP_THREADSAFE
-  global_ble->notify_main_loop_();
+  App.wake_loop_threadsafe();
 #endif
 }
 #endif
@@ -623,8 +611,8 @@ void ESP32BLE::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gat
                                    esp_ble_gattc_cb_param_t *param) {
   enqueue_ble_event(event, gattc_if, param);
   // Wake up main loop to process GATT event immediately
-#ifdef USE_SOCKET_SELECT_SUPPORT
+#ifdef USE_WAKE_LOOP_THREADSAFE
-  global_ble->notify_main_loop_();
+  App.wake_loop_threadsafe();
 #endif
 }
 #endif
@@ -665,89 +653,6 @@ void ESP32BLE::dump_config() {
   }
 }
 
-#ifdef USE_SOCKET_SELECT_SUPPORT
-void ESP32BLE::setup_event_notification_() {
-  // Create UDP socket for event notifications
-  this->notify_fd_ = lwip_socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
-  if (this->notify_fd_ < 0) {
-    ESP_LOGW(TAG, "Event socket create failed: %d", errno);
-    return;
-  }
-
-  // Bind to loopback with auto-assigned port
-  struct sockaddr_in addr = {};
-  addr.sin_family = AF_INET;
-  addr.sin_addr.s_addr = lwip_htonl(INADDR_LOOPBACK);
-  addr.sin_port = 0;  // Auto-assign port
-
-  if (lwip_bind(this->notify_fd_, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
-    ESP_LOGW(TAG, "Event socket bind failed: %d", errno);
-    lwip_close(this->notify_fd_);
-    this->notify_fd_ = -1;
-    return;
-  }
-
-  // Get the assigned address and connect to it
-  // Connecting a UDP socket allows using send() instead of sendto() for better performance
-  struct sockaddr_in notify_addr;
-  socklen_t len = sizeof(notify_addr);
-  if (lwip_getsockname(this->notify_fd_, (struct sockaddr *) &notify_addr, &len) < 0) {
-    ESP_LOGW(TAG, "Event socket address failed: %d", errno);
-    lwip_close(this->notify_fd_);
-    this->notify_fd_ = -1;
-    return;
-  }
-
-  // Connect to self (loopback) - allows using send() instead of sendto()
-  // After connect(), no need to store notify_addr - the socket remembers it
-  if (lwip_connect(this->notify_fd_, (struct sockaddr *) &notify_addr, sizeof(notify_addr)) < 0) {
-    ESP_LOGW(TAG, "Event socket connect failed: %d", errno);
-    lwip_close(this->notify_fd_);
-    this->notify_fd_ = -1;
-    return;
-  }
-
-  // Set non-blocking mode
-  int flags = lwip_fcntl(this->notify_fd_, F_GETFL, 0);
-  lwip_fcntl(this->notify_fd_, F_SETFL, flags | O_NONBLOCK);
-
-  // Register with application's select() loop
-  if (!App.register_socket_fd(this->notify_fd_)) {
-    ESP_LOGW(TAG, "Event socket register failed");
-    lwip_close(this->notify_fd_);
-    this->notify_fd_ = -1;
-    return;
-  }
-
-  ESP_LOGD(TAG, "Event socket ready");
-}
-
-void ESP32BLE::cleanup_event_notification_() {
-  if (this->notify_fd_ >= 0) {
-    App.unregister_socket_fd(this->notify_fd_);
-    lwip_close(this->notify_fd_);
-    this->notify_fd_ = -1;
-    ESP_LOGD(TAG, "Event socket closed");
-  }
-}
-
-void ESP32BLE::drain_event_notifications_() {
-  // Called from main loop to drain any pending notifications
-  // Must check is_socket_ready() to avoid blocking on empty socket
-  if (this->notify_fd_ >= 0 && App.is_socket_ready(this->notify_fd_)) {
-    char buffer[BLE_EVENT_NOTIFY_DRAIN_BUFFER_SIZE];
-    // Drain all pending notifications with non-blocking reads
-    // Multiple BLE events may have triggered multiple writes, so drain until EWOULDBLOCK
-    // We control both ends of this loopback socket (always write 1 byte per event),
-    // so no error checking needed - any errors indicate catastrophic system failure
-    while (lwip_recvfrom(this->notify_fd_, buffer, sizeof(buffer), 0, nullptr, nullptr) > 0) {
-      // Just draining, no action needed - actual BLE events are already queued
-    }
-  }
-}
-
-#endif  // USE_SOCKET_SELECT_SUPPORT
-
 uint64_t ble_addr_to_uint64(const esp_bd_addr_t address) {
   uint64_t u = 0;
   u |= uint64_t(address[0] & 0xFF) << 40;

esphome/components/esp32_ble/ble.h

@@ -166,12 +166,10 @@ class ESP32BLE : public Component {
   void advertising_init_();
 #endif
 
-#ifdef USE_SOCKET_SELECT_SUPPORT
+  // BLE uses the core wake_loop_threadsafe() mechanism to wake the main event loop
-  void setup_event_notification_();    // Create notification socket
+  // from BLE tasks. This enables low-latency (~12μs) event processing instead of
-  void cleanup_event_notification_();  // Close and unregister socket
+  // waiting for select() timeout (0-16ms). The wake socket is shared with other
-  inline void notify_main_loop_();     // Wake up select() from BLE thread (hot path - inlined)
+  // components that need this functionality.
-  void drain_event_notifications_();   // Read pending notifications in main loop
-#endif
 
  private:
   template<typename... Args> friend void enqueue_ble_event(Args... args);
@@ -207,13 +205,6 @@ class ESP32BLE : public Component {
   esp_ble_io_cap_t io_cap_{ESP_IO_CAP_NONE};  // 4 bytes (enum)
   uint32_t advertising_cycle_time_{};         // 4 bytes
 
-#ifdef USE_SOCKET_SELECT_SUPPORT
-  // Event notification socket for waking up main loop from BLE thread
-  // Uses connected UDP loopback socket to wake lwip_select() with ~12μs latency vs 0-16ms timeout
-  // Socket is connected during setup, allowing use of send() instead of sendto() for efficiency
-  int notify_fd_{-1};  // 4 bytes (file descriptor)
-#endif
-
   // 2-byte aligned members
   uint16_t appearance_{0};  // 2 bytes
 
@@ -225,29 +216,6 @@ class ESP32BLE : public Component {
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 extern ESP32BLE *global_ble;
 
-#ifdef USE_SOCKET_SELECT_SUPPORT
-// Inline implementations for hot-path functions
-// These are called from BLE thread (notify) and main loop (drain) on every event
-
-// Small buffer for draining notification bytes (1 byte sent per BLE event)
-// Size allows draining multiple notifications per recvfrom() without wasting stack
-static constexpr size_t BLE_EVENT_NOTIFY_DRAIN_BUFFER_SIZE = 16;
-
-inline void ESP32BLE::notify_main_loop_() {
-  // Called from BLE thread context when events are queued
-  // Wakes up lwip_select() in main loop by writing to connected loopback socket
-  if (this->notify_fd_ >= 0) {
-    const char dummy = 1;
-    // Non-blocking send - if it fails (unlikely), select() will wake on timeout anyway
-    // No error checking needed: we control both ends of this loopback socket, and the
-    // BLE event is already queued. Notification is best-effort to reduce latency.
-    // This is safe to call from BLE thread - send() is thread-safe in lwip
-    // Socket is already connected to loopback address, so send() is faster than sendto()
-    lwip_send(this->notify_fd_, &dummy, 1, 0);
-  }
-}
-#endif  // USE_SOCKET_SELECT_SUPPORT
-
 template<typename... Ts> class BLEEnabledCondition : public Condition<Ts...> {
  public:
   bool check(Ts... x) override { return global_ble->is_active(); }

esphome/core/application.cpp

@@ -122,6 +122,11 @@ void Application::setup() {
   // Clear setup priority overrides to free memory
   clear_setup_priority_overrides();
 
+#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
+  // Set up wake socket for waking main loop from tasks
+  this->setup_wake_loop_threadsafe_();
+#endif
+
   this->schedule_dump_config();
 }
 void Application::loop() {
@@ -472,6 +477,11 @@ void Application::enable_pending_loops_() {
 }
 
 void Application::before_loop_tasks_(uint32_t loop_start_time) {
+#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
+  // Drain wake notifications first to clear socket for next wake
+  this->drain_wake_notifications_();
+#endif
+
   // Process scheduled tasks
   this->scheduler.call(loop_start_time);
 
@@ -625,4 +635,73 @@ void Application::yield_with_select_(uint32_t delay_ms) {
 
 Application App;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
+#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
+void Application::setup_wake_loop_threadsafe_() {
+  // Create UDP socket for wake notifications
+  this->wake_socket_fd_ = lwip_socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+  if (this->wake_socket_fd_ < 0) {
+    ESP_LOGW(TAG, "Wake socket create failed: %d", errno);
+    return;
+  }
+
+  // Bind to loopback with auto-assigned port
+  struct sockaddr_in addr = {};
+  addr.sin_family = AF_INET;
+  addr.sin_addr.s_addr = lwip_htonl(INADDR_LOOPBACK);
+  addr.sin_port = 0;  // Auto-assign port
+
+  if (lwip_bind(this->wake_socket_fd_, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
+    ESP_LOGW(TAG, "Wake socket bind failed: %d", errno);
+    lwip_close(this->wake_socket_fd_);
+    this->wake_socket_fd_ = -1;
+    return;
+  }
+
+  // Get the assigned address and connect to it
+  // Connecting a UDP socket allows using send() instead of sendto() for better performance
+  struct sockaddr_in wake_addr;
+  socklen_t len = sizeof(wake_addr);
+  if (lwip_getsockname(this->wake_socket_fd_, (struct sockaddr *) &wake_addr, &len) < 0) {
+    ESP_LOGW(TAG, "Wake socket address failed: %d", errno);
+    lwip_close(this->wake_socket_fd_);
+    this->wake_socket_fd_ = -1;
+    return;
+  }
+
+  // Connect to self (loopback) - allows using send() instead of sendto()
+  // After connect(), no need to store wake_addr - the socket remembers it
+  if (lwip_connect(this->wake_socket_fd_, (struct sockaddr *) &wake_addr, sizeof(wake_addr)) < 0) {
+    ESP_LOGW(TAG, "Wake socket connect failed: %d", errno);
+    lwip_close(this->wake_socket_fd_);
+    this->wake_socket_fd_ = -1;
+    return;
+  }
+
+  // Set non-blocking mode
+  int flags = lwip_fcntl(this->wake_socket_fd_, F_GETFL, 0);
+  lwip_fcntl(this->wake_socket_fd_, F_SETFL, flags | O_NONBLOCK);
+
+  // Register with application's select() loop
+  if (!this->register_socket_fd(this->wake_socket_fd_)) {
+    ESP_LOGW(TAG, "Wake socket register failed");
+    lwip_close(this->wake_socket_fd_);
+    this->wake_socket_fd_ = -1;
+    return;
+  }
+}
+
+void Application::wake_loop_threadsafe() {
+  // Called from FreeRTOS task context when events need immediate processing
+  // Wakes up lwip_select() in main loop by writing to connected loopback socket
+  if (this->wake_socket_fd_ >= 0) {
+    const char dummy = 1;
+    // Non-blocking send - if it fails (unlikely), select() will wake on timeout anyway
+    // No error checking needed: we control both ends of this loopback socket.
+    // This is safe to call from FreeRTOS tasks - send() is thread-safe in lwip
+    // Socket is already connected to loopback address, so send() is faster than sendto()
+    lwip_send(this->wake_socket_fd_, &dummy, 1, 0);
+  }
+}
+#endif  // defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
+
 }  // namespace esphome

esphome/core/application.h

@@ -21,7 +21,20 @@
 
 #ifdef USE_SOCKET_SELECT_SUPPORT
 #include <sys/select.h>
+
+#ifdef USE_WAKE_LOOP_THREADSAFE
+// Inline function drain_wake_notifications_() needs lwip socket functions
+#ifdef USE_SOCKET_IMPL_LWIP_SOCKETS
+#include <lwip/sockets.h>
+#elif defined(USE_SOCKET_IMPL_BSD_SOCKETS)
+#ifdef USE_ESP32
+#include <lwip/sockets.h>
+#else
+// True BSD sockets already included via sys/select.h
 #endif
+#endif
+#endif  // USE_WAKE_LOOP_THREADSAFE
+#endif  // USE_SOCKET_SELECT_SUPPORT
 
 #ifdef USE_BINARY_SENSOR
 #include "esphome/components/binary_sensor/binary_sensor.h"
@@ -429,6 +442,13 @@ class Application {
   /// Check if there's data available on a socket without blocking
   /// This function is thread-safe for reading, but should be called after select() has run
   bool is_socket_ready(int fd) const;
+
+#ifdef USE_WAKE_LOOP_THREADSAFE
+  /// Wake the main event loop from a FreeRTOS task
+  /// Thread-safe, can be called from task context to immediately wake select()
+  /// IMPORTANT: NOT safe to call from ISR context (socket operations not ISR-safe)
+  void wake_loop_threadsafe();
+#endif
 #endif
 
  protected:
@@ -454,6 +474,11 @@ class Application {
   /// Perform a delay while also monitoring socket file descriptors for readiness
   void yield_with_select_(uint32_t delay_ms);
 
+#if defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
+  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
+
   // === Member variables ordered by size to minimize padding ===
 
   // Pointer-sized members first
@@ -481,6 +506,9 @@ class Application {
   FixedVector<Component *> looping_components_{};
 #ifdef USE_SOCKET_SELECT_SUPPORT
   std::vector<int> socket_fds_;  // Vector of all monitored socket file descriptors
+#ifdef USE_WAKE_LOOP_THREADSAFE
+  int wake_socket_fd_{-1};  // Shared wake notification socket for waking main loop from tasks
+#endif
 #endif
 
   // std::string members (typically 24-32 bytes each)
@@ -597,4 +625,28 @@ 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_WAKE_LOOP_THREADSAFE)
+// Inline implementations for hot-path functions
+// drain_wake_notifications_() is called on every loop iteration
+
+// Small buffer for draining wake notification bytes (1 byte sent per wake)
+// Size allows draining multiple notifications per recvfrom() without wasting stack
+static constexpr size_t WAKE_NOTIFY_DRAIN_BUFFER_SIZE = 16;
+
+inline void Application::drain_wake_notifications_() {
+  // Called from main loop to drain any pending wake notifications
+  // Must check is_socket_ready() to avoid blocking on empty socket
+  if (this->wake_socket_fd_ >= 0 && this->is_socket_ready(this->wake_socket_fd_)) {
+    char buffer[WAKE_NOTIFY_DRAIN_BUFFER_SIZE];
+    // Drain all pending notifications with non-blocking reads
+    // Multiple wake events may have triggered multiple writes, so drain until EWOULDBLOCK
+    // We control both ends of this loopback socket (always write 1 byte per wake),
+    // so no error checking needed - any errors indicate catastrophic system failure
+    while (lwip_recvfrom(this->wake_socket_fd_, buffer, sizeof(buffer), 0, nullptr, nullptr) > 0) {
+      // Just draining, no action needed - wake has already occurred
+    }
+  }
+}
+#endif  // defined(USE_SOCKET_SELECT_SUPPORT) && defined(USE_WAKE_LOOP_THREADSAFE)
+
 }  // namespace esphome

esphome/cpp_helpers.py

@@ -9,7 +9,7 @@ from esphome.const import (
 )
 from esphome.core import CORE, ID, coroutine
 from esphome.coroutine import FakeAwaitable
-from esphome.cpp_generator import LogStringLiteral, add, get_variable
+from esphome.cpp_generator import LogStringLiteral, add, add_define, get_variable
 from esphome.cpp_types import App
 from esphome.types import ConfigFragmentType, ConfigType
 from esphome.util import Registry, RegistryEntry
@@ -124,3 +124,34 @@ async def past_safe_mode():
             yield
 
     return await FakeAwaitable(_safe_mode_generator())
+
+
+# Wake loop threadsafe support tracking
+# Components that need to wake the main event loop from FreeRTOS tasks can call require_wake_loop_threadsafe()
+KEY_WAKE_LOOP_THREADSAFE_REQUIRED = "wake_loop_threadsafe_required"
+
+
+def require_wake_loop_threadsafe() -> None:
+    """Mark that wake_loop_threadsafe support is required by a component.
+
+    Call this from components that need to wake the main event loop from FreeRTOS tasks.
+    This enables the shared UDP loopback socket mechanism (~208 bytes RAM).
+    The socket is shared across all components that use this feature.
+
+    IMPORTANT: This is for FreeRTOS task context only, NOT ISR context.
+    Socket operations are not safe to call from ISR handlers.
+
+    Example:
+        import esphome.codegen as cg
+
+        async def to_code(config):
+            cg.require_wake_loop_threadsafe()
+    """
+    # Only set up once (idempotent - multiple components can call this)
+    if not CORE.data.get(KEY_WAKE_LOOP_THREADSAFE_REQUIRED, False):
+        from esphome.components import socket
+
+        CORE.data[KEY_WAKE_LOOP_THREADSAFE_REQUIRED] = True
+        add_define("USE_WAKE_LOOP_THREADSAFE")
+        # Consume 1 socket for the shared wake notification socket
+        socket.consume_sockets(1, "core.wake_loop_threadsafe")({})

tests/unit_tests/test_cpp_helpers.py

@@ -70,3 +70,43 @@ async def test_register_component__with_setup_priority(monkeypatch):
     assert add_mock.call_count == 4
     app_mock.register_component.assert_called_with(var)
     assert core_mock.component_ids == []
+
+
+def test_require_wake_loop_threadsafe__first_call() -> None:
+    """Test that first call sets up define and consumes socket."""
+    ch.require_wake_loop_threadsafe()
+
+    # Verify CORE.data was updated
+    assert ch.CORE.data[ch.KEY_WAKE_LOOP_THREADSAFE_REQUIRED] is True
+
+    # Verify the define was added
+    assert any(d.name == "USE_WAKE_LOOP_THREADSAFE" for d in ch.CORE.defines)
+
+
+def test_require_wake_loop_threadsafe__idempotent() -> None:
+    """Test that subsequent calls are idempotent."""
+    # Set up initial state as if already called
+    ch.CORE.data[ch.KEY_WAKE_LOOP_THREADSAFE_REQUIRED] = True
+
+    # Call again - should not raise or fail
+    ch.require_wake_loop_threadsafe()
+
+    # Verify state is still True
+    assert ch.CORE.data[ch.KEY_WAKE_LOOP_THREADSAFE_REQUIRED] is True
+
+    # Define should not be added since flag was already True
+    assert not any(d.name == "USE_WAKE_LOOP_THREADSAFE" for d in ch.CORE.defines)
+
+
+def test_require_wake_loop_threadsafe__multiple_calls() -> None:
+    """Test that multiple calls only set up once."""
+    # Call three times
+    ch.require_wake_loop_threadsafe()
+    ch.require_wake_loop_threadsafe()
+    ch.require_wake_loop_threadsafe()
+
+    # Verify CORE.data was set
+    assert ch.CORE.data[ch.KEY_WAKE_LOOP_THREADSAFE_REQUIRED] is True
+
+    # Verify the define was added (only once, but we can just check it exists)
+    assert any(d.name == "USE_WAKE_LOOP_THREADSAFE" for d in ch.CORE.defines)