[core] Allow finding all devices as target that match mac suffix (#13135)

esphome/async_thread.py

@@ -0,0 +1,56 @@
+"""Helpers for running an async coroutine from sync code via a daemon thread.
+
+``asyncio.run(coro())`` in the main thread blocks until the loop's cleanup
+cycle finishes, which can add hundreds of milliseconds before the caller
+receives the result. Running the loop in a daemon thread lets the caller
+observe the result as soon as the coroutine completes while cleanup finishes
+in the background.
+"""
+
+from __future__ import annotations
+
+import asyncio
+from collections.abc import Awaitable, Callable
+import threading
+from typing import Generic, TypeVar
+
+_T = TypeVar("_T")
+
+
+class AsyncThreadRunner(threading.Thread, Generic[_T]):
+    """Run an async coroutine in a daemon thread and expose its result.
+
+    The runner catches all exceptions from the coroutine and stores them in
+    ``exception`` so ``event`` is always set — this prevents callers waiting
+    on ``event`` from hanging forever when the coroutine crashes.
+
+    Typical usage::
+
+        runner = AsyncThreadRunner(lambda: my_coro(arg))
+        runner.start()
+        if not runner.event.wait(timeout=5.0):
+            ...  # timed out
+        if runner.exception is not None:
+            raise runner.exception
+        result = runner.result
+    """
+
+    def __init__(self, coro_factory: Callable[[], Awaitable[_T]]) -> None:
+        super().__init__(daemon=True)
+        self._coro_factory = coro_factory
+        self.result: _T | None = None
+        self.exception: BaseException | None = None
+        self.event = threading.Event()
+
+    async def _runner(self) -> None:
+        try:
+            self.result = await self._coro_factory()
+        except Exception as exc:  # pylint: disable=broad-except
+            # Capture all exceptions so ``event`` is always set — otherwise a
+            # crash would hang the waiter forever.
+            self.exception = exc
+        finally:
+            self.event.set()
+
+    def run(self) -> None:
+        asyncio.run(self._runner())