[3.14] pythongh-91555: Revert disabling of logger while handling log record. (pythonGH-135858) (pythonGH-135910)

Co-authored-by: Vinay Sajip <[email protected]>

Author: miss-islington

Lib/logging/__init__.py

@@ -1475,8 +1475,6 @@ class Logger(Filterer):
     level, and "input.csv", "input.xls" and "input.gnu" for the sub-levels.
     There is no arbitrary limit to the depth of nesting.
     """
-    _tls = threading.local()
-
     def __init__(self, name, level=NOTSET):
         """
         Initialize the logger with a name and an optional level.
@@ -1673,19 +1671,14 @@ def handle(self, record):
         This method is used for unpickled records received from a socket, as
         well as those created locally. Logger-level filtering is applied.
         """
-        if self._is_disabled():
+        if self.disabled:
             return
-
-        self._tls.in_progress = True
-        try:
-            maybe_record = self.filter(record)
-            if not maybe_record:
-                return
-            if isinstance(maybe_record, LogRecord):
-                record = maybe_record
-            self.callHandlers(record)
-        finally:
-            self._tls.in_progress = False
+        maybe_record = self.filter(record)
+        if not maybe_record:
+            return
+        if isinstance(maybe_record, LogRecord):
+            record = maybe_record
+        self.callHandlers(record)
 
     def addHandler(self, hdlr):
         """
@@ -1773,7 +1766,7 @@ def isEnabledFor(self, level):
         """
         Is this logger enabled for level 'level'?
         """
-        if self._is_disabled():
+        if self.disabled:
             return False
 
         try:
@@ -1823,11 +1816,6 @@ def _hierlevel(logger):
                        if isinstance(item, Logger) and item.parent is self and
                        _hierlevel(item) == 1 + _hierlevel(item.parent))
 
-    def _is_disabled(self):
-        # We need to use getattr as it will only be set the first time a log
-        # message is recorded on any given thread
-        return self.disabled or getattr(self._tls, 'in_progress', False)
-
     def __repr__(self):
         level = getLevelName(self.getEffectiveLevel())
         return '<%s %s (%s)>' % (self.__class__.__name__, self.name, level)

Lib/test/test_logging.py

@@ -4214,89 +4214,6 @@ def __init__(self, *args, **kwargs):
         handler = logging.getHandlerByName('custom')
         self.assertEqual(handler.custom_kwargs, custom_kwargs)
 
-    # See gh-91555 and gh-90321
-    @support.requires_subprocess()
-    def test_deadlock_in_queue(self):
-        queue = multiprocessing.Queue()
-        handler = logging.handlers.QueueHandler(queue)
-        logger = multiprocessing.get_logger()
-        level = logger.level
-        try:
-            logger.setLevel(logging.DEBUG)
-            logger.addHandler(handler)
-            logger.debug("deadlock")
-        finally:
-            logger.setLevel(level)
-            logger.removeHandler(handler)
-
-    def test_recursion_in_custom_handler(self):
-        class BadHandler(logging.Handler):
-            def __init__(self):
-                super().__init__()
-            def emit(self, record):
-                logger.debug("recurse")
-        logger = logging.getLogger("test_recursion_in_custom_handler")
-        logger.addHandler(BadHandler())
-        logger.setLevel(logging.DEBUG)
-        logger.debug("boom")
-
-    @threading_helper.requires_working_threading()
-    def test_thread_supression_noninterference(self):
-        lock = threading.Lock()
-        logger = logging.getLogger("test_thread_supression_noninterference")
-
-        # Block on the first call, allow others through
-        #
-        # NOTE: We need to bypass the base class's lock, otherwise that will
-        #       block multiple calls to the same handler itself.
-        class BlockOnceHandler(TestHandler):
-            def __init__(self, barrier):
-                super().__init__(support.Matcher())
-                self.barrier = barrier
-
-            def createLock(self):
-                self.lock = None
-
-            def handle(self, record):
-                self.emit(record)
-
-            def emit(self, record):
-                if self.barrier:
-                    barrier = self.barrier
-                    self.barrier = None
-                    barrier.wait()
-                    with lock:
-                        pass
-                super().emit(record)
-                logger.info("blow up if not supressed")
-
-        barrier = threading.Barrier(2)
-        handler = BlockOnceHandler(barrier)
-        logger.addHandler(handler)
-        logger.setLevel(logging.DEBUG)
-
-        t1 = threading.Thread(target=logger.debug, args=("1",))
-        with lock:
-
-            # Ensure first thread is blocked in the handler, hence supressing logging...
-            t1.start()
-            barrier.wait()
-
-            # ...but the second thread should still be able to log...
-            t2 = threading.Thread(target=logger.debug, args=("2",))
-            t2.start()
-            t2.join(timeout=3)
-
-            self.assertEqual(len(handler.buffer), 1)
-            self.assertTrue(handler.matches(levelno=logging.DEBUG, message='2'))
-
-            # The first thread should still be blocked here
-            self.assertTrue(t1.is_alive())
-
-        # Now the lock has been released the first thread should complete
-        t1.join()
-        self.assertEqual(len(handler.buffer), 2)
-        self.assertTrue(handler.matches(levelno=logging.DEBUG, message='1'))
 
 class ManagerTest(BaseTest):
     def test_manager_loggerclass(self):

Misc/NEWS.d/3.14.0b2.rst

@@ -512,7 +512,7 @@ Bénédikt Tran.
 .. section: Library
 
 Ignore log messages generated during handling of log messages, to avoid
-deadlock or infinite recursion.
+deadlock or infinite recursion. [NOTE: This change has since been reverted.]
 
 ..
 

Misc/NEWS.d/next/Library/2025-06-25-17-25-53.gh-issue-91555.xUpTLD.rst

@@ -0,0 +1,4 @@
+An earlier change, which was introduced in 3.14.0b2, has been reverted. It
+disabled logging for a logger during handling of log messages for that
+logger. Since the reversion, the behaviour should be as it was before
+3.14.0b2.