Fix leak on cloning functions with update defs #7735
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When cloning a Func with an update def, the remapping map resulting from the deep copy may already contain a key for the wrapped function pointing to a strong reference to itself. The reasons are unclear to me, but it means that emplace silently does nothing and we get a memory leak because the cloned Func's update definition has a strong self-reference after the remapping is applied. We want to replace it with a weak reference, so this PR changes things to use operator[] instead of emplace.
steven-johnson
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Aug 1, 2023
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Failures unrelated, landing |
ardier
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Mar 3, 2024
* Fix leak on cloning functions with update defs When cloning a Func with an update def, the remapping map resulting from the deep copy may already contain a key for the wrapped function pointing to a strong reference to itself. The reasons are unclear to me, but it means that emplace silently does nothing and we get a memory leak because the cloned Func's update definition has a strong self-reference after the remapping is applied. We want to replace it with a weak reference, so this PR changes things to use operator[] instead of emplace. * Add comment
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When cloning a Func with an update def, the remapping map resulting from the deep copy may already contain a key for the wrapped function pointing to a strong reference to itself. The reasons are unclear to me, but it means that emplace silently does nothing and we get a memory leak because the cloned Func's update definition has a strong self-reference after the remapping is applied.
We want to replace it with a weak reference, so this PR changes things to use operator[] instead of emplace.