unwrap ForwardingSubchannel during Picks#12658
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shivaspeaks wants to merge 6 commits intogrpc:masterfrom
Draft
unwrap ForwardingSubchannel during Picks#12658shivaspeaks wants to merge 6 commits intogrpc:masterfrom
shivaspeaks wants to merge 6 commits intogrpc:masterfrom
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ejona86
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Feb 17, 2026
xds/src/test/java/io/grpc/xds/WeightedRoundRobinLoadBalancerTest.java
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Please also check the description of the PR, if we need to add anything or remove anything. |
ejona86
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Feb 19, 2026
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You should probably mark this PR as "Ready for review" (not Draft).
loosely-typed attributes
Attributes are strongly-typed. It's more about not needing to abuse attributes so to re-discover what should already be known.
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| private static final class OrcaOobPicker extends SubchannelPicker { | ||
| private final SubchannelPicker delegate; | ||
| static final class OrcaOobPicker extends SubchannelPicker { |
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Add @VisibleForTesting to both of these.
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This PR ensures that Load Balancing (LB) policies unwrap
ForwardingSubchannelinstances before returning them in aPickResult.Rationale: Currently, the identity of a subchannel is "awkward" because decorators break object identity. This forces the core channel to use internal workarounds like
getInternalSubchannel()to find the underlying implementation. Removing these wrappers during the pick process is a critical prerequisite for deleting Subchannel Attributes.By enforcing unwrapping,
ManagedChannelImplcan rely on the fact that a returned subchannel is the same instance it originally created. This allows the channel to use strongly-typed fields for state management (via "blind casting") rather than loosely-typed attributes. This also paves the way for the eventual removal of thegetInternalSubchannel()internal API.New APIs: To ensure we don't "drop data on the floor" during the unwrapping process, this PR adds two new non-static APIs to PickResult:
Unlike static factory methods, these instance methods follow a "copy-and-update" pattern that preserves all existing pick-level metadata (such as authority overrides or drop status) while only swapping the specific field required.