aquire logging lock using _lock context manager

Aquire the logging lock using the underlying _lock object from the
logging module.

As of python/cpython#3385, included in Python 3.7, this object an instance
of threading.RLock whose use as a context manager with release being
called when the block exits, see
https://docs.python.org/3/library/threading.html#using-locks-conditions-and-semaphores-in-the-with-statement

Author: jjhelmus

conda/common/io.py

@@ -279,14 +279,14 @@ def disable_logger(logger_name):
     logr = getLogger(logger_name)
     _lvl, _dsbld, _prpgt = logr.level, logr.disabled, logr.propagate
     null_handler = NullHandler()
-    with _logger_lock():
+    with logging._lock:
         logr.addHandler(null_handler)
         logr.setLevel(CRITICAL + 1)
         logr.disabled, logr.propagate = True, False
     try:
         yield
     finally:
-        with _logger_lock():
+        with logging._lock:
             logr.removeHandler(null_handler)  # restore list logr.handlers
             logr.level, logr.disabled = _lvl, _dsbld
             logr.propagate = _prpgt
@@ -305,15 +305,15 @@ def stderr_log_level(level, logger_name=None):
     handler.name = "stderr"
     handler.setLevel(level)
     handler.setFormatter(_FORMATTER)
-    with _logger_lock():
+    with logging._lock:
         logr.setLevel(level)
         logr.handlers, logr.disabled, logr.propagate = [], False, False
         logr.addHandler(handler)
         logr.setLevel(level)
     try:
         yield
     finally:
-        with _logger_lock():
+        with logging._lock:
             logr.handlers, logr.level, logr.disabled = _hndlrs, _lvl, _dsbld
             logr.propagate = _prpgt
 
@@ -354,7 +354,7 @@ def attach_stderr_handler(
         new_stderr_handler.addFilter(filter_)
 
     # do the switch
-    with _logger_lock():
+    with logging._lock:
         if old_stderr_handler:
             logr.removeHandler(old_stderr_handler)
         logr.addHandler(new_stderr_handler)