Issue #9945: logging: Fixed locking bugs in addHandler/removeHandler.

Lib/logging/__init__.py

@@ -1263,20 +1263,23 @@ class Logger(Filterer):
         """
         Add the specified handler to this logger.
         """
+        _acquireLock()
+        try:
             if not (hdlr in self.handlers):
                 self.handlers.append(hdlr)
+        finally:
+            _releaseLock()
 
     def removeHandler(self, hdlr):
         """
         Remove the specified handler from this logger.
         """
-        if hdlr in self.handlers:
-            #hdlr.close()
-            hdlr.acquire()
+        _acquireLock()
         try:
+            if hdlr in self.handlers:
                 self.handlers.remove(hdlr)
         finally:
-                hdlr.release()
+            _releaseLock()
 
     def callHandlers(self, record):
         """

Misc/NEWS

@@ -43,6 +43,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #9945: logging: Fixed locking bugs in addHandler/removeHandler.
+
 - Issue #9936: Fixed executable lines' search in the trace module.
 
 - Issue #9928: Properly initialize the types exported by the bz2 module.