https://github.com/python/cpython/commit/a6c4080aaa646d8d3a0e54a6de7557b230c09341 commit: a6c4080aaa646d8d3a0e54a6de7557b230c09341 branch: 3.13 author: Miss Islington (bot) <[email protected]> committer: zooba <[email protected]> date: 2024-06-11T19:35:49Z summary:
gh-120198: Fix race condition when editing __class__ with an audit hook active (GH-120195) (cherry picked from commit 203565b2f9c74656ba519780049b46d4e5afcba1) Co-authored-by: Ken Jin <[email protected]> files: A Misc/NEWS.d/next/Core and Builtins/2024-06-10-15-07-16.gh-issue-120198.WW_pjO.rst M Lib/test/test_free_threading/test_type.py M Lib/test/test_super.py M Objects/typeobject.c diff --git a/Lib/test/test_free_threading/test_type.py b/Lib/test/test_free_threading/test_type.py index 6eead198deed46..786336fa0cddce 100644 --- a/Lib/test/test_free_threading/test_type.py +++ b/Lib/test/test_free_threading/test_type.py @@ -1,3 +1,4 @@ +import threading import unittest from concurrent.futures import ThreadPoolExecutor diff --git a/Lib/test/test_super.py b/Lib/test/test_super.py index 256b416caaa584..3ffbe03f0c2f11 100644 --- a/Lib/test/test_super.py +++ b/Lib/test/test_super.py @@ -1,9 +1,10 @@ """Unit tests for zero-argument super() & related machinery.""" import textwrap +import threading import unittest from unittest.mock import patch -from test.support import import_helper +from test.support import import_helper, threading_helper ADAPTIVE_WARMUP_DELAY = 2 @@ -505,6 +506,38 @@ def some(cls): for _ in range(ADAPTIVE_WARMUP_DELAY): C.some(C) + @threading_helper.requires_working_threading() + def test___class___modification_multithreaded(self): + """ Note: this test isn't actually testing anything on its own. + It requires a sys audithook to be set to crash on older Python. + This should be the case anyways as our test suite sets + an audit hook. + """ + class Foo: + pass + + class Bar: + pass + + thing = Foo() + def work(): + foo = thing + for _ in range(5000): + foo.__class__ = Bar + type(foo) + foo.__class__ = Foo + type(foo) + + + threads = [] + for _ in range(6): + thread = threading.Thread(target=work) + thread.start() + threads.append(thread) + + for thread in threads: + thread.join() + if __name__ == "__main__": unittest.main() diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-06-10-15-07-16.gh-issue-120198.WW_pjO.rst b/Misc/NEWS.d/next/Core and Builtins/2024-06-10-15-07-16.gh-issue-120198.WW_pjO.rst new file mode 100644 index 00000000000000..8dc8aec44d80c4 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2024-06-10-15-07-16.gh-issue-120198.WW_pjO.rst @@ -0,0 +1 @@ +Fix a crash when multiple threads read and write to the same ``__class__`` of an object concurrently. diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 18b7dfce3d8038..2d001b76e09775 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -6363,7 +6363,6 @@ compatible_for_assignment(PyTypeObject* oldto, PyTypeObject* newto, const char* static int object_set_class(PyObject *self, PyObject *value, void *closure) { - PyTypeObject *oldto = Py_TYPE(self); if (value == NULL) { PyErr_SetString(PyExc_TypeError, @@ -6383,6 +6382,8 @@ object_set_class(PyObject *self, PyObject *value, void *closure) return -1; } + PyTypeObject *oldto = Py_TYPE(self); + /* In versions of CPython prior to 3.5, the code in compatible_for_assignment was not set up to correctly check for memory layout / slot / etc. compatibility for non-HEAPTYPE classes, so we just _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
