Overhaul set benchmarks: split Immutable / SingleThreaded, add Set.copyOf#11721
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…pyOf Mirror the map-benchmark overhaul for sets. Replace the single SetBenchmark (shared mutable counter under @threads(8); contains_treeSet bug that queried HASH_SET) with two classes that each pick the right threading model: - ImmutableSetBenchmark: fixed read-only membership shared across threads (@State(Scope.Benchmark)); array / sortedArray / HashSet / TreeSet / Set.copyOf (the JDK compact SetN the agent actually uses for config sets, via CollectionUtils.tryMakeImmutableSet). hit/miss split, per-thread cursor. - SingleThreadedSetBenchmark: per-thread mutable lifecycle (@State(Scope.Thread)); create/clone + contains/iterate, plus a Collections.synchronizedSet case for the uncontended synchronization tax (per-thread => bias never revoked; biased-locking story across JVMs). StringIndex rows fold in later. Result blocks empty pending a fresh multi-JVM run. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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…edMapBenchmark StringIndex's benchmark integration is moving to the dedicated benchmark PRs (set overhaul #11721, map overhaul #11679) and will be folded in there later. Revert both benchmark files to master so this PR is purely the StringIndex data structure + tests. Avoids the #11679/#11721 deletions-vs-edits conflicts too. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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What
Overhauls the
internal-apiset membership benchmarks, mirroring the map-benchmark overhaul (#11679). Replaces the singleSetBenchmarkwith two classes that each pick the correct threading model for their use case (@Statescope can't vary by@Param, so one class can't host both):ImmutableSetBenchmark— fixed, read-only membership shared across threads (@State(Scope.Benchmark); sharing is realistic and contention-free since nothing mutates). Comparesarray/sortedArray/HashSet/TreeSet/Set.copyOf(the JDK's compact, array-backedImmutableCollections.SetN, viaCollectionUtils.tryMakeImmutableSet— what the agent actually uses for fixed config sets). hit/miss split, per-thread lookup cursor. Sets in the tracer skew strongly toward this shape.SingleThreadedSetBenchmark— per-thread mutable lifecycle (@State(Scope.Thread)):create/clone+contains/iterate, plus aCollections.synchronizedSetcase for the uncontended synchronization tax (each thread owns its set → monitor only ever locked by one thread → the biased-locking story, read across JVM versions). UnsynchronizedHashSetis the in-harness baseline.Why
The old
SetBenchmarkused a shared mutable rotation counter under@Threads(8)(turning fast structures into a contention measurement) and had acontains_treeSetthat actually queriedHASH_SET. The split fixes both, and theSet.copyOfcase answers a real question: for our ~10 fixedstatic final HashSetconfig sites, is the JDK's compact immutable set better thanHashSeton speed/footprint?Notes
Set.copyOfonly materializes the compactSetNon Java 10+ (falls back toHashSetpre-10); the synchronizedSet biased-locking delta shows across Java 11 → 17. Result blocks are intentionally empty pending a fresh multi-JVM run.StringIndex(Add StringIndex: a generic open-addressed string set #11660) rows fold into these later — kept out so this lands independent of that data structure.🤖 Generated with Claude Code