Visitar URL original
gh-135552: Make the GC clear weakrefs later by nascheme · Pull Request #136189 · python/cpython · GitHub
Skip to content

gh-135552: Make the GC clear weakrefs later #136189

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
nascheme merged 20 commits into from
Aug 7, 2025
Merged

gh-135552: Make the GC clear weakrefs later #136189

Changes from 1 commit
Commits
Show all changes
20 commits
Select commit Hold shift + click to select a range
42abb05
Make the GC clear weakrefs later.
nascheme Jun 30, 2025
17a4f9e
Remove inaccurate comment.
nascheme Jul 1, 2025
12f0b5c
Run clear_weakrefs() with world stopped.
nascheme Jul 1, 2025
2f3daba
Defer weakref clears only for refs to classes.
nascheme Jul 2, 2025
123bc25
Ensure weakrefs with callbacks are cleared early.
nascheme Jul 3, 2025
496c0b1
Add NEWS.
nascheme Jul 3, 2025
8a553d1
Add comment about wrlist iteration.
nascheme Jul 3, 2025
01c882f
Merge 'origin/main' into gh-135552-wr-clear-later
nascheme Jul 3, 2025
0060602
Merge 'origin/main' into gh-135552-wr-clear-later
nascheme Jul 8, 2025
900022b
Revise NEWS.
nascheme Jul 8, 2025
84bd123
Defer clear for weakrefs without callbacks.
nascheme Jul 8, 2025
bb29ea1
Add unit test for GH-132413.
nascheme Jul 8, 2025
073409b
Add additional tests for weakref clearing.
nascheme Jul 9, 2025
135223e
Revert unneeded changes to unit tests.
nascheme Jul 9, 2025
fe9e58a
Use assertIsNone() and assertIsNotNone().
nascheme Jul 23, 2025
70ef387
Merge 'origin/main' into gh-135552-wr-clear-later
nascheme Jul 23, 2025
a7551cf
Merge 'origin/main' into gh-135552-wr-clear-later
nascheme Aug 6, 2025
4fe8de0
Revise InternalDocs/garbage_collector.md.
nascheme Aug 7, 2025
24fd972
Revise comments about weakref handling.
nascheme Aug 7, 2025
eca79ce
Merge branch 'origin/main' into gh-135552-wr-clear-later
nascheme Aug 7, 2025
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
Prev Previous commit
Next Next commit
Use assertIsNone() and assertIsNotNone().
  • Loading branch information
@nascheme
nascheme committed Jul 23, 2025
commit fe9e58a0aff6c80de606c5e9349d488b3b194e96
26 changes: 13 additions & 13 deletions Lib/test/test_finalization.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -174,7 +174,7 @@ def test_simple(self):
gc.collect()
self.assert_del_calls(ids)
self.assert_survivors([])
self.assertIs(wr(), None)
self.assertIsNone(wr())
gc.collect()
self.assert_del_calls(ids)
self.assert_survivors([])
Expand All @@ -188,12 +188,12 @@ def test_simple_resurrect(self):
gc.collect()
self.assert_del_calls(ids)
self.assert_survivors(ids)
self.assertIsNot(wr(), None)
self.assertIsNotNone(wr())
self.clear_survivors()
gc.collect()
self.assert_del_calls(ids)
self.assert_survivors([])
self.assertIs(wr(), None)
self.assertIsNone(wr())

@support.cpython_only
def test_non_gc(self):
Expand Down Expand Up @@ -265,7 +265,7 @@ def test_simple(self):
gc.collect()
self.assert_del_calls(ids)
self.assert_survivors([])
self.assertIs(wr(), None)
self.assertIsNone(wr())
gc.collect()
self.assert_del_calls(ids)
self.assert_survivors([])
Expand All @@ -283,7 +283,7 @@ def test_simple_resurrect(self):
self.assert_survivors(ids)
# This used to be None because weakrefs were cleared before
# calling finalizers. Now they are cleared after.
self.assertIsNot(wr(), None)
self.assertIsNotNone(wr())
# A weakref with a callback is still cleared before calling
# finalizers.
self.assertIsNone(wrc())
Expand All @@ -293,7 +293,7 @@ def test_simple_resurrect(self):
gc.collect()
self.assert_del_calls(ids)
self.assert_survivors([])
self.assertIs(wr(), None)
self.assertIsNone(wr())

def test_simple_suicide(self):
# Test the GC is able to deal with an object that kills its last
Expand All @@ -306,11 +306,11 @@ def test_simple_suicide(self):
gc.collect()
self.assert_del_calls(ids)
self.assert_survivors([])
self.assertIs(wr(), None)
self.assertIsNone(wr())
gc.collect()
self.assert_del_calls(ids)
self.assert_survivors([])
self.assertIs(wr(), None)
self.assertIsNone(wr())


class ChainedBase:
Expand Down Expand Up @@ -505,7 +505,7 @@ def test_legacy(self):
self.assert_del_calls(ids)
self.assert_tp_del_calls(ids)
self.assert_survivors([])
self.assertIs(wr(), None)
self.assertIsNone(wr())
gc.collect()
self.assert_del_calls(ids)
self.assert_tp_del_calls(ids)
Expand All @@ -521,13 +521,13 @@ def test_legacy_resurrect(self):
self.assert_tp_del_calls(ids)
self.assert_survivors(ids)
# weakrefs are cleared before tp_del is called.
self.assertIs(wr(), None)
self.assertIsNone(wr())
self.clear_survivors()
gc.collect()
self.assert_del_calls(ids)
self.assert_tp_del_calls(ids * 2)
self.assert_survivors(ids)
self.assertIs(wr(), None)
self.assertIsNone(wr())

def test_legacy_self_cycle(self):
# Self-cycles with legacy finalizers end up in gc.garbage.
Expand All @@ -541,11 +541,11 @@ def test_legacy_self_cycle(self):
self.assert_tp_del_calls([])
self.assert_survivors([])
self.assert_garbage(ids)
self.assertIsNot(wr(), None)
self.assertIsNotNone(wr())
# Break the cycle to allow collection
gc.garbage[0].ref = None
self.assert_garbage([])
self.assertIs(wr(), None)
self.assertIsNone(wr())


if __name__ == "__main__":
Expand Down