Always do thread safety check when writing state (#118886)

* Always do thread safety check when writing state

Refactor the 3 most common places where the thread safety check
for the event loop to be inline to make the check fast enough
that we can keep it long term. While code review catches most
of the thread safety issues in core, some of them still make
it through, and new ones keep getting added. Its not possible
to catch them all with manual code review, so its worth the
tiny overhead to check each time.

Previously the check was limited to custom components
because they were the most common source of thread
safety issues.

* Always do thread safety check when writing state

Refactor the 3 most common places where the thread safety check
for the event loop to be inline to make the check fast enough
that we can keep it long term. While code review catches most
of the thread safety issues in core, some of them still make
it through, and new ones keep getting added. Its not possible
to catch them all with manual code review, so its worth the
tiny overhead to check each time.

Previously the check was limited to custom components
because they were the most common source of thread
safety issues.

* async_fire is more common than expected with ccs

* fix mock

* fix hass mocking

homeassistant/core.py

@@ -434,25 +434,17 @@ class HomeAssistant:
         self.import_executor = InterruptibleThreadPoolExecutor(
             max_workers=1, thread_name_prefix="ImportExecutor"
         )
-        self._loop_thread_id = getattr(
+        self.loop_thread_id = getattr(
             self.loop, "_thread_ident", getattr(self.loop, "_thread_id")
         )
 
     def verify_event_loop_thread(self, what: str) -> None:
         """Report and raise if we are not running in the event loop thread."""
-        if self._loop_thread_id != threading.get_ident():
+        if self.loop_thread_id != threading.get_ident():
+            # frame is a circular import, so we import it here
             from .helpers import frame  # pylint: disable=import-outside-toplevel
 
-            # frame is a circular import, so we import it here
-            frame.report(
-                f"calls {what} from a thread other than the event loop, "
-                "which may cause Home Assistant to crash or data to corrupt. "
-                "For more information, see "
-                "https://developers.home-assistant.io/docs/asyncio_thread_safety/"
-                f"#{what.replace('.', '')}",
-                error_if_core=True,
-                error_if_integration=True,
-            )
+            frame.report_non_thread_safe_operation(what)
 
     @property
     def _active_tasks(self) -> set[asyncio.Future[Any]]:
@@ -793,16 +785,10 @@ class HomeAssistant:
 
         target: target to call.
         """
-        # We turned on asyncio debug in April 2024 in the dev containers
-        # in the hope of catching some of the issues that have been
-        # reported. It will take a while to get all the issues fixed in
-        # custom components.
-        #
-        # In 2025.5 we should guard the `verify_event_loop_thread`
-        # check with a check for the `hass.config.debug` flag being set as
-        # long term we don't want to be checking this in production
-        # environments since it is a performance hit.
-        self.verify_event_loop_thread("hass.async_create_task")
+        if self.loop_thread_id != threading.get_ident():
+            from .helpers import frame  # pylint: disable=import-outside-toplevel
+
+            frame.report_non_thread_safe_operation("hass.async_create_task")
         return self.async_create_task_internal(target, name, eager_start)
 
     @callback
@@ -1497,7 +1483,10 @@ class EventBus:
         This method must be run in the event loop.
         """
         _verify_event_type_length_or_raise(event_type)
-        self._hass.verify_event_loop_thread("hass.bus.async_fire")
+        if self._hass.loop_thread_id != threading.get_ident():
+            from .helpers import frame  # pylint: disable=import-outside-toplevel
+
+            frame.report_non_thread_safe_operation("hass.bus.async_fire")
         return self.async_fire_internal(
             event_type, event_data, origin, context, time_fired
         )

homeassistant/helpers/entity.py

@@ -14,6 +14,7 @@ import logging
 import math
 from operator import attrgetter
 import sys
+import threading
 import time
 from types import FunctionType
 from typing import TYPE_CHECKING, Any, Final, Literal, NotRequired, TypedDict, final
@@ -63,6 +64,7 @@ from .event import (
     async_track_device_registry_updated_event,
     async_track_entity_registry_updated_event,
 )
+from .frame import report_non_thread_safe_operation
 from .typing import UNDEFINED, StateType, UndefinedType
 
 timer = time.time
@@ -512,7 +514,6 @@ class Entity(
     # While not purely typed, it makes typehinting more useful for us
     # and removes the need for constant None checks or asserts.
     _state_info: StateInfo = None  # type: ignore[assignment]
-    _is_custom_component: bool = False
 
     __capabilities_updated_at: deque[float]
     __capabilities_updated_at_reported: bool = False
@@ -995,8 +996,8 @@ class Entity(
     def async_write_ha_state(self) -> None:
         """Write the state to the state machine."""
         self._async_verify_state_writable()
-        if self._is_custom_component or self.hass.config.debug:
-            self.hass.verify_event_loop_thread("async_write_ha_state")
+        if self.hass.loop_thread_id != threading.get_ident():
+            report_non_thread_safe_operation("async_write_ha_state")
         self._async_write_ha_state()
 
     def _stringify_state(self, available: bool) -> str:
@@ -1440,8 +1441,6 @@ class Entity(
             "domain": self.platform.platform_name,
             "custom_component": is_custom_component,
         }
-        self._is_custom_component = is_custom_component
-
         if self.platform.config_entry:
             entity_info["config_entry"] = self.platform.config_entry.entry_id
 

homeassistant/helpers/frame.py

@@ -218,3 +218,16 @@ def warn_use[_CallableT: Callable](func: _CallableT, what: str) -> _CallableT:
             report(what)
 
     return cast(_CallableT, report_use)
+
+
+def report_non_thread_safe_operation(what: str) -> None:
+    """Report a non-thread safe operation."""
+    report(
+        f"calls {what} from a thread other than the event loop, "
+        "which may cause Home Assistant to crash or data to corrupt. "
+        "For more information, see "
+        "https://developers.home-assistant.io/docs/asyncio_thread_safety/"
+        f"#{what.replace('.', '')}",
+        error_if_core=True,
+        error_if_integration=True,
+    )

tests/common.py

@@ -174,7 +174,7 @@ def get_test_home_assistant() -> Generator[HomeAssistant, None, None]:
         """Run event loop."""
 
         loop._thread_ident = threading.get_ident()
-        hass._loop_thread_id = loop._thread_ident
+        hass.loop_thread_id = loop._thread_ident
         loop.run_forever()
         loop_stop_event.set()
 

tests/components/zha/test_cluster_handlers.py

@@ -3,6 +3,7 @@
 from collections.abc import Callable
 import logging
 import math
+import threading
 from types import NoneType
 from unittest import mock
 from unittest.mock import AsyncMock, patch
@@ -86,6 +87,7 @@ def endpoint(zigpy_coordinator_device):
     type(endpoint_mock.device).skip_configuration = mock.PropertyMock(
         return_value=False
     )
+    endpoint_mock.device.hass.loop_thread_id = threading.get_ident()
     endpoint_mock.id = 1
     return endpoint_mock
 

tests/helpers/test_entity.py

@@ -2617,13 +2617,12 @@ async def test_async_write_ha_state_thread_safety(hass: HomeAssistant) -> None:
     assert not hass.states.get(ent2.entity_id)
 
 
-async def test_async_write_ha_state_thread_safety_custom_component(
+async def test_async_write_ha_state_thread_safety_always(
     hass: HomeAssistant,
 ) -> None:
-    """Test async_write_ha_state thread safe for custom components."""
+    """Test async_write_ha_state thread safe check."""
 
     ent = entity.Entity()
-    ent._is_custom_component = True
     ent.entity_id = "test.any"
     ent.hass = hass
     ent.platform = MockEntityPlatform(hass, domain="test")
@@ -2631,7 +2630,6 @@ async def test_async_write_ha_state_thread_safety_custom_component(
     assert hass.states.get(ent.entity_id)
 
     ent2 = entity.Entity()
-    ent2._is_custom_component = True
     ent2.entity_id = "test.any2"
     ent2.hass = hass
     ent2.platform = MockEntityPlatform(hass, domain="test")