Hi,
I'm trying to write an example of usage of the new
tracemalloc.get_object_traceback() function. Last month I proposed to
use it to give the traceback where a file/socket was allocated on
ResourceWarning:
https://mail.python.org/pipermail/python-dev/2013-October/129923.html
I found a working solution using monkey patching of the socket, _pyio
and builtins modules:
https://bitbucket.org/haypo/misc/src/tip/python/res_warn.py
This hack uses tracemalloc to retrieve the traceback where the
file/socket was allocated, but you can do the same using
traceback.extract_stack() for older Python version. So it's just an
example to show how tracemalloc can be used.
Example with test_poplib (without res_warn.py):
[1/1] test_poplib
/home/haypo/prog/python/default/Lib/test/support/__init__.py:1331:
ResourceWarning: unclosed
gc.collect()
Ok, you now that the socket was destroyed be the garbage collector...
But which test created this socket???
Example of res_warn.py with test_poplib:
[1/1] test_poplib
/home/haypo/prog/python/default/Lib/test/support/__init__.py:1331:
ResourceWarning: unclosed
gc.collect()
Allocation traceback (most recent first):
File '/home/haypo/prog/python/default/Lib/ssl.py', line 340
_context=self)
File '/home/haypo/prog/python/default/Lib/poplib.py', line 390
self.sock = context.wrap_socket(self.sock)
File '/home/haypo/prog/python/default/Lib/test/test_poplib.py', line 407
self.client.stls()
File '/home/haypo/prog/python/default/Lib/unittest/case.py', line 567
self.setUp()
File '/home/haypo/prog/python/default/Lib/unittest/case.py', line 610
return self.run(*args, **kwds)
(...)
You can see that the socket was created by test_poplib at line 407
TestPOP3_TLSClass.setUp). It's more useful than the previous warning
:-)
I found two issues in _pyio and tracemalloc modules. These issues
should be fixed to use res_warn.py on text or buffered files and use
it during Python shutdown:
http://bugs.python.org/issue19831
http://bugs.python.org/issue19829
Victor
___
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe:
https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
