8000 GH-104142: Fix `_Py_RefcntAdd` to respect immortality by brandtbucher · Pull Request #104143 · python/cpython · GitHub
[go: up one dir, main page]
Skip to content

GH-104142: Fix _Py_RefcntAdd to respect immortality #104143

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
May 5, 2023
Merged

GH-104142: Fix _Py_RefcntAdd to respect immortality #104143

Changes from 1 commit
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
e24771b
Add failing regression tests
brandtbucher May 3, 2023
9338eea
Fix _Py_RefcntAdd
brandtbucher May 3, 2023
be3b103
blurb add
brandtbucher May 3, 2023
1471b39
Merge branch 'main' into py-refcnt-add-immortal
JelleZijlstra May 4, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
Add failing regression tests
  • Loading branch information
@brandtbucher
brandtbucher committed May 3, 2023
commit e24771bf3449a12c1c0c71d9fa55b63be059bf30
43 changes: 25 additions & 18 deletions Lib/test/test_builtin.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2372,24 +2372,31 @@ def __del__(self):

@cpython_only
class ImmortalTests(unittest.TestCase):
def test_immortal(self):
none_refcount = sys.getrefcount(None)
true_refcount = sys.getrefcount(True)
false_refcount = sys.getrefcount(False)
smallint_refcount = sys.getrefcount(100)

# Assert that all of these immortal instances have large ref counts.
self.assertGreater(none_refcount, 2 ** 15)
self.assertGreater(true_refcount, 2 ** 15)
self.assertGreater(false_refcount, 2 ** 15)
self.assertGreater(smallint_refcount, 2 ** 15)

# Confirm that the refcount doesn't change even with a new ref to them.
l = [None, True, False, 100]
self.assertEqual(sys.getrefcount(None), none_refcount)
self.assertEqual(sys.getrefcount(True), true_refcount)
self.assertEqual(sys.getrefcount(False), false_refcount)
self.assertEqual(sys.getrefcount(100), smallint_refcount)

if sys.maxsize < (1 << 32):
IMMORTAL_REFCOUNT = (1 << 30) - 1
else:
IMMORTAL_REFCOUNT = (1 << 32) - 1

IMMORTALS = (None, True, False, Ellipsis, NotImplemented, *range(-5, 257))

def assert_immortal(self, immortal):
with self.subTest(immortal):
self.assertEqual(sys.getrefcount(immortal), self.IMMORTAL_REFCOUNT)

def test_immortals(self):
for immortal in self.IMMORTALS:
Copy link
Contributor
@eduardo-elizondo eduardo-elizondo May 4, 2023 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Small nit: I generally prefer rolling out assertions in unit tests to make it easier to isolate by line-number in the place where the test failed. But I don't think there's a standard in the code base so I'm fine either way

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yeah, I'd like comprehensive testing of these immortals though, and I don't want to roll out ~250 different assertions for each test.

I figured making each one a subTest in assert_immortal is a pretty good compromise.

self.assert_immortal(immortal)

def test_list_repeat_respect_immortality(self):
refs = list(self.IMMORTALS) * 42
for immortal in self.IMMORTALS:
self.assert_immortal(immortal)

def test_tuple_repeat_respect_immortality(self):
refs = tuple(self.IMMORTALS) * 42
for immortal in self.IMMORTALS:
self.assert_immortal(immortal)


class TestType(unittest.TestCase):
Expand Down
0