Avoid multiple executor jobs with concurrent calls to async_get_component (#112155)

tests/test_loader.py

@@ -2,6 +2,7 @@
 import asyncio
 import os
 import sys
+import threading
 from typing import Any
 from unittest.mock import MagicMock, Mock, patch
 
@@ -1086,8 +1087,8 @@ async def test_async_get_component_loads_loop_if_already_in_sys_modules(
     assert integration.import_executor is True
     assert integration.config_flow is True
 
-    assert "executor_import" not in hass.config.components
-    assert "executor_import.config_flow" not in hass.config.components
+    assert "test_package_loaded_executor" not in hass.config.components
+    assert "test_package_loaded_executor.config_flow" not in hass.config.components
 
     config_flow_module_name = f"{integration.pkg_path}.config_flow"
     module_mock = MagicMock()
@@ -1133,6 +1134,64 @@ async def test_async_get_component_loads_loop_if_already_in_sys_modules(
     assert module is module_mock
 
 
+async def test_async_get_component_concurrent_loads(
+    hass: HomeAssistant,
+    caplog: pytest.LogCaptureFixture,
+    enable_custom_integrations: None,
+) -> None:
+    """Verify async_get_component waits if the first load if called again when still in progress."""
+    integration = await loader.async_get_integration(
+        hass, "test_package_loaded_executor"
+    )
+    assert integration.pkg_path == "custom_components.test_package_loaded_executor"
+    assert integration.import_executor is True
+    assert integration.config_flow is True
+
+    assert "test_package_loaded_executor" not in hass.config.components
+    assert "test_package_loaded_executor.config_flow" not in hass.config.components
+
+    config_flow_module_name = f"{integration.pkg_path}.config_flow"
+    module_mock = MagicMock()
+    config_flow_module_mock = MagicMock()
+    imports = []
+    start_event = threading.Event()
+    import_event = asyncio.Event()
+
+    def import_module(name: str) -> Any:
+        hass.loop.call_soon_threadsafe(import_event.set)
+        imports.append(name)
+        start_event.wait()
+        if name == integration.pkg_path:
+            return module_mock
+        if name == config_flow_module_name:
+            return config_flow_module_mock
+        raise ImportError
+
+    modules_without_integration = {
+        k: v
+        for k, v in sys.modules.items()
+        if k != config_flow_module_name and k != integration.pkg_path
+    }
+    with patch.dict(
+        "sys.modules",
+        {**modules_without_integration},
+        clear=True,
+    ), patch("homeassistant.loader.importlib.import_module", import_module):
+        load_task1 = asyncio.create_task(integration.async_get_component())
+        load_task2 = asyncio.create_task(integration.async_get_component())
+        await import_event.wait()  # make sure the import is started
+        assert not integration._component_future.done()
+        start_event.set()
+        comp1 = await load_task1
+        comp2 = await load_task2
+        assert integration._component_future is None
+
+    assert comp1 is module_mock
+    assert comp2 is module_mock
+
+    assert imports == [integration.pkg_path, config_flow_module_name]
+
+
 async def test_async_get_component_deadlock_fallback(
     hass: HomeAssistant, caplog: pytest.LogCaptureFixture
 ) -> None: