From 1297a093443ac2243b4fcca402434f7cdf364d3f Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 17 May 2020 07:39:27 -0500
Subject: [PATCH] Avoid locking in the logging queue handler (#35700)

* Avoid locking in the logging queue handler

We do not need a lock here as the underlying queue is already
thread safe.

* Add coverage for logging handle
---
 homeassistant/util/logging.py | 18 ++++++++++++++++++
 tests/util/test_logging.py    | 11 +++++++++++
 2 files changed, 29 insertions(+)

diff --git a/homeassistant/util/logging.py b/homeassistant/util/logging.py
index 07ee6608141e..943e701a1446 100644
--- a/homeassistant/util/logging.py
+++ b/homeassistant/util/logging.py
@@ -39,6 +39,24 @@ class HomeAssistantQueueHandler(logging.handlers.QueueHandler):
         except Exception:  # pylint: disable=broad-except
             self.handleError(record)
 
+    def handle(self, record: logging.LogRecord) -> Any:
+        """
+        Conditionally emit the specified logging record.
+
+        Depending on which filters have been added to the handler, push the new
+        records onto the backing Queue.
+
+        The default python logger Handler acquires a lock
+        in the parent class which we do not need as
+        SimpleQueue is already thread safe.
+
+        See https://bugs.python.org/issue24645
+        """
+        return_value = self.filter(record)
+        if return_value:
+            self.emit(record)
+        return return_value
+
 
 @callback
 def async_activate_log_queue_handler(hass: HomeAssistant) -> None:
diff --git a/tests/util/test_logging.py b/tests/util/test_logging.py
index a1183ee16372..04d6f133381b 100644
--- a/tests/util/test_logging.py
+++ b/tests/util/test_logging.py
@@ -38,6 +38,17 @@ async def test_logging_with_queue_handler():
     ):
         handler.emit(log_record)
 
+    with patch.object(handler, "emit") as emit_mock:
+        handler.handle(log_record)
+        emit_mock.assert_called_once()
+
+    with patch.object(handler, "filter") as filter_mock, patch.object(
+        handler, "emit"
+    ) as emit_mock:
+        filter_mock.return_value = False
+        handler.handle(log_record)
+        emit_mock.assert_not_called()
+
     with patch.object(handler, "enqueue", side_effect=OSError), patch.object(
         handler, "handleError"
     ) as mock_handle_error: