[New-bugs-announce] [issue19523] logging.FileHandler - using of delay argument case handler leaks
DDGG
report at bugs.python.org
Fri Nov 8 04:40:03 CET 2013
New submission from DDGG:
Issue File: Python26\Lib\logging\__init__.py
class FileHandler(StreamHandler):
"""
A handler class which writes formatted logging records to disk files.
"""
def __init__(self, filename, mode='a', encoding=None, delay=0):
"""
Open the specified file and use it as the stream for logging.
"""
#keep the absolute path, otherwise derived classes which use this
#may come a cropper when the current directory changes
if codecs is None:
encoding = None
self.baseFilename = os.path.abspath(filename)
self.mode = mode
self.encoding = encoding
if delay:
#We don't open the stream, but we still need to call the
#Handler constructor to set level, formatter, lock etc.
Handler.__init__(self) ## 1. here will insert instance into logging._handlerList
self.stream = None
else:
StreamHandler.__init__(self, self._open())
def close(self):
"""
Closes the stream.
"""
if self.stream: ## 2. when delay=1, here should call Handler.close(self), or the instance still store in logging._handlerList, lead to leak (instance's owner's __del__ will not be called).
self.flush()
if hasattr(self.stream, "close"):
self.stream.close()
StreamHandler.close(self)
self.stream = None
------------------------------------------------
leak demo:
import logging
import time
def using_handler():
filename = "test.log"
handler = logging.FileHandler(filename, mode="w", delay=1)
handler.close()
def test():
while True:
using_handler()
time.sleep(.01)
if __name__ == "__main__":
test()
If you run this script, and then view the Task Manager for this process's handlers, it is growing forever.
------------------------------------
Solution: very easy
Fix the method FileHandler.close:
def close(self):
"""
Closes the stream.
"""
if self.stream:
self.flush()
if hasattr(self.stream, "close"):
self.stream.close()
StreamHandler.close(self)
self.stream = None
else:
Handler.close(self)
regards
DDGG
----------
components: Library (Lib)
messages: 202403
nosy: DDGG
priority: normal
severity: normal
status: open
title: logging.FileHandler - using of delay argument case handler leaks
type: behavior
versions: Python 2.6
_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue19523>
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