Fix weakref garbage collection race condition in DNS resolver manager #10923
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Fix `AttributeError: NoneType object has no attribute cancel` in DNS resolver cleanup Downstream users reported a crash during test teardown with the following error: ``` AttributeError: NoneType object has no attribute cancel ``` The issue occurs in `_DNSResolverManager.release_resolver()` when the weakref-managed resolver object gets garbage collected before it can be properly cancelled. This creates a race condition where the resolver reference becomes `None` but the cleanup code still tries to call `resolver.cancel()`.
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Codecov ReportAll modified and coverable lines are covered by tests ✅
✅ All tests successful. No failed tests found. Additional details and impacted files@@ Coverage Diff @@
## master #10923 +/- ##
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Coverage 98.75% 98.75%
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Files 129 129
Lines 39072 39095 +23
Branches 2164 2166 +2
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+ Hits 38586 38609 +23
Misses 337 337
Partials 149 149
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CodSpeed Performance ReportMerging #10923 will not alter performanceComparing Summary
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Backport to 3.12: 💚 backport PR created✅ Backport PR branch: Backported as #10924 🤖 @patchback |
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…ce condition in DNS resolver manager (#10924) Co-authored-by: J. Nick Koston <[email protected]>
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Fix
AttributeError: NoneType object has no attribute cancelin DNS resolver cleanupDownstream users reported a crash during test teardown with the following error:
The issue occurs in
_DNSResolverManager.release_resolver()when the weakref-managed resolver object gets garbage collected before it can be properly cancelled. This creates a race condition where the resolver reference becomesNonebut the cleanup code still tries to callresolver.cancel().