gh-140080: Fix atexit with low memory

[yihong0618]

fix the error that's forget the cleanup

cc @ZeroIntensity @picnixz and it also turns out its not the _testcapi_setnomemroy(0) issue.

seems the news can skip?

after this patch no hang anymore

• Issue: The REPL hangs under low memory on main #140080

[ZeroIntensity]

Since the 3.15 alpha is today, please add a news entry so we can know what was fixed in the next release.

Also, per usual, this needs a test case. At a glance, this should be reproducible by calling set_nomemory after registering an atexit callback.

[yihong0618]

Since the 3.15 alpha is today, please add a news entry so we can know what was fixed in the next release.

Also, per usual, this needs a test case. At a glance, this should be reproducible by calling set_nomemory after registering an atexit callback.

of course will try, but the test things maybe need some help( - -)
will try it.

and also bring the 3.13(no_memory) tests is that under plan need to add in this pull request?

[ZeroIntensity]

and also bring the 3.13(no_memory) tests is that under plan need to add in this pull request?

Let's do that in a different PR, because we'll want that in 3.14 as well.

[yihong0618]

and also bring the 3.13(no_memory) tests is that under plan need to add in this pull request?

Let's do that in a different PR, because we'll want that in 3.14 as well.

ok will do it later, thank you for the help~

[yihong0618]

Since the 3.15 alpha is today, please add a news entry so we can know what was fixed in the next release.

Also, per usual, this needs a test case. At a glance, this should be reproducible by calling set_nomemory after registering an atexit callback.

Done, before the patch the tests hangs
after the patch the tests pas

tests from #138491

[vstinner]

LGTM

[vstinner]

Python 3.13 is not affected, atexit doesn't use PyObject *copy = PyList_GetSlice(state->callbacks, 0, PyList_GET_SIZE(state->callbacks)); in this version.

[yihong0618]

Python 3.13 is not affected, atexit doesn't use PyObject *copy = PyList_GetSlice(state->callbacks, 0, PyList_GET_SIZE(state->callbacks)); in this version.

FYI: 3.14 not hang
and #136004 this patch seems did not backport to it.

[yihong0618]

LGTM

Thank you!

[ZeroIntensity]

Yeah, this doesn't affect 3.14, so we shouldn't backport it there.

@yihong0618 After this is merged, would you mind creating a PR to 3.14 with the test from this PR?

[yihong0618]

Yeah, this doesn't affect 3.14, so we shouldn't backport it there.

@yihong0618 After this is merged, would you mind creating a PR to 3.14 with the test from this PR?

of course with pleasure to do it thank you

[vstinner]

Why not backporting this change to 3.14?

[ZeroIntensity]

Why not backporting this change to 3.14?

On 3.14, we don't execute atexit callbacks in a loop, so if PyList_GetSlice fails, it will correctly bail out and continue with finalization.