Stop boxing WeakReferenceListEnumerator in PresentationSource use #6502
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PresentationSource.CriticalCurrentSources is internal and is only ever foreach'd by consumers. It's strongly-typed to return IEnumerable, but the actual WeakReferenceList it returns has a struct-based enumerator, which means each foreach boxes that enumerator. By changing CriticalCurrentSources to return `WeakReferenceList` rather than `IEnumerable`, those foreach's can bind directly to the struct, with all the benefits that brings.
ghost
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ghost
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dipeshmsft
approved these changes
Jul 19, 2022
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Description
PresentationSource.CriticalCurrentSources is internal and is only ever foreach'd by consumers. It's strongly-typed to return IEnumerable, but the actual WeakReferenceList it returns has a struct-based enumerator, which means each foreach boxes that enumerator. By changing CriticalCurrentSources to return
WeakReferenceListrather thanIEnumerable, those foreach's can bind directly to the struct, with all the benefits that brings.Customer Impact
Unnecessary allocation
Regression
No
Testing
CI
Risk
Minimal
Microsoft Reviewers: Open in CodeFlow