TrioBackend: Fixed UDP listener crashing down application on `recvfro…

…m()` errors (#371)

src/easynetwork/lowlevel/api_async/backend/_trio/datagram/listener.py

@@ -20,6 +20,7 @@
 __all__ = ["TrioDatagramListenerSocketAdapter"]
 
 import contextlib
+import logging
 import socket as _socket
 import warnings
 from collections.abc import Awaitable, Callable, Coroutine, Mapping
@@ -102,14 +103,20 @@ async def serve(
             MAX_DATAGRAM_BUFSIZE = self.MAX_DATAGRAM_BUFSIZE
             listener = self.__listener
             wait_readable = self.__wait_readable
+            logger = logging.getLogger(__name__)
 
             while True:
-                datagram, client_address = await _retry_socket_method(
-                    wait_readable,
-                    listener,
-                    lambda: listener.recvfrom(MAX_DATAGRAM_BUFSIZE),
-                    always_yield=True,
-                )
+                try:
+                    datagram, client_address = await _retry_socket_method(
+                        wait_readable,
+                        listener,
+                        lambda: listener.recvfrom(MAX_DATAGRAM_BUFSIZE),
+                        always_yield=True,
+                    )
+                except OSError as exc:
+                    message = "Unrelated error occurred on datagram reception: %s: %s"
+                    logger.warning(message, type(exc).__name__, exc, exc_info=exc)
+                    continue
 
                 task_group.start_soon(handler, datagram, client_address)
                 # Always drop references on loop end

tests/unit_test/test_async/test_trio_backend/test_datagram.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import contextlib
+import logging
 from collections.abc import AsyncIterator, Callable
 from typing import TYPE_CHECKING, Any
 
@@ -295,8 +296,10 @@ async def test____serve____default(
         mock_udp_listener_socket: MagicMock,
         mock_trio_lowlevel_wait_readable: AsyncMock,
         mocker: MockerFixture,
+        caplog: pytest.LogCaptureFixture,
     ) -> None:
         # Arrange
+        caplog.set_level("INFO", listener.__class__.__module__)
 
         import trio
 
@@ -305,6 +308,9 @@ async def test____serve____default(
             (b"received_datagram", ("127.0.0.1", 12345)),
             (b"received_datagram_2", ("127.0.0.1", 54321)),
             BlockingIOError,
+            OSError("Unrelated OS Error"),
+            (b"received_datagram_3", ("127.0.0.1", 11111)),
+            BlockingIOError,
             (await self._get_cancelled_exc()),
         ]
 
@@ -318,8 +324,13 @@ async def test____serve____default(
         assert handler.await_args_list == [
             mocker.call(b"received_datagram", ("127.0.0.1", 12345)),
             mocker.call(b"received_datagram_2", ("127.0.0.1", 54321)),
+            mocker.call(b"received_datagram_3", ("127.0.0.1", 11111)),
         ]
-        assert mock_trio_lowlevel_wait_readable.await_args_list == [mocker.call(mock_udp_listener_socket) for _ in range(2)]
+        assert mock_trio_lowlevel_wait_readable.await_args_list == [mocker.call(mock_udp_listener_socket) for _ in range(3)]
+        assert len(caplog.records) == 1
+        assert caplog.records[0].levelno == logging.WARNING
+        assert caplog.records[0].getMessage() == "Unrelated error occurred on datagram reception: OSError: Unrelated OS Error"
+        assert caplog.records[0].exc_info is not None and isinstance(caplog.records[0].exc_info[1], OSError)
 
     @pytest.mark.parametrize("block_count", [2, 1, 0], ids=lambda count: f"block_count=={count}")
     async def test____send_to____write_on_socket(