Memory leak in os.path.isdir under Windows

[nneonneo]

BPO	17051
Nosy	@briancurtin, @serhiy-storchaka

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = 'https://github.com/serhiy-storchaka'
closed_at = <Date 2013-01-28.18:25:27.644>
created_at = <Date 2013-01-27.09:10:56.135>
labels = ['extension-modules', 'OS-windows', 'performance']
title = 'Memory leak in os.path.isdir under Windows'
updated_at = <Date 2013-01-28.19:30:36.313>
user = 'https://bugs.python.org/nneonneo'

bugs.python.org fields:

activity = <Date 2013-01-28.19:30:36.313>
actor = 'brian.curtin'
assignee = 'serhiy.storchaka'
closed = True
closed_date = <Date 2013-01-28.18:25:27.644>
closer = 'serhiy.storchaka'
components = ['Extension Modules', 'Windows']
creation = <Date 2013-01-27.09:10:56.135>
creator = 'nneonneo'
dependencies = []
files = []
hgrepos = []
issue_num = 17051
keywords = []
message_count = 7.0
messages = ['180754', '180762', '180772', '180869', '180870', '180872', '180874']
nosy_count = 4.0
nosy_names = ['nneonneo', 'brian.curtin', 'python-dev', 'serhiy.storchaka']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'resource usage'
url = 'https://bugs.python.org/issue17051'
versions = ['Python 2.7']

[nneonneo]

[From http://stackoverflow.com/questions/12648737/huge-memory-leak-in-repeated-os-path-isdir-calls]

os.path.isdir() leaks memory under Windows in Python 2.7. The core cause is this snippet:

Modules/posixmodule.c:4226:
if (!PyArg_ParseTuple(args, "et:_isdir",
Py_FileSystemDefaultEncoding, &path))
return NULL;

    attributes = GetFileAttributesA(path);
    if (attributes == INVALID_FILE_ATTRIBUTES)
        Py_RETURN_FALSE;

check:
    if (attributes & FILE_ATTRIBUTE_DIRECTORY)
        Py_RETURN_TRUE;
    else
        Py_RETURN_FALSE;

The buffer returned by the "et" ParseTuple format must be freed after use. Since it isn't freed, we get a memory leak here.

Patch:

--- a/Modules/posixmodule.c	Mon Apr 09 19:04:04 2012 -0400
+++ b/Modules/posixmodule.c	Sun Jan 27 04:10:34 2013 -0500
@@ -4226,6 +4226,7 @@
         return NULL;
 
     attributes = GetFileAttributesA(path);
+    PyMem_Free(path);
     if (attributes == INVALID_FILE_ATTRIBUTES)
         Py_RETURN_FALSE;

[serhiy-storchaka]

Good catch. Thank you, Robert Xiao.

Can you please submit a contributor form?

http://python.org/psf/contrib/contrib-form/
http://python.org/psf/contrib/

[nneonneo]

The PSF form really needs a PDF version. Anyway, 'tis duly submitted.

[python-dev]

New changeset 4deb294ff567 by Serhiy Storchaka in branch '2.7':
Issue bpo-17051: Fix a memory leak in os.path.isdir() on Windows. Patch by Robert Xiao.
http://hg.python.org/cpython/rev/4deb294ff567

[serhiy-storchaka]

Committed. Thank you for patch.

[python-dev]

New changeset 51173aba06eb by Serhiy Storchaka in branch '2.7':
Add Robert Xiao to Misc/ACKS for bpo-17051.
http://hg.python.org/cpython/rev/51173aba06eb

[briancurtin]

Robert, thanks a lot for this fix and your contributor agreement. We're currently working on making it easier to submit the contributor agreement so you won't have to print it out and mail/fax/scan it...even though you already did it and you're now covered :)