Summary

Adds three new JMH benchmark classes in org.apache.groovy.perf.grails that reproduce the real-world invokedynamic performance regression observed in Grails 7 applications (GROOVY-10307).

Benchmark Classes

CallSiteInvalidationBench (11 benchmarks)

Tests the core SwitchPoint invalidation mechanism - the root cause of the regression. Demonstrates that modifying ANY metaclass triggers global invalidation affecting ALL call sites:

• Cross-type invalidation at 3 frequencies (every 100/1000/10000 iterations)
• Same-type invalidation for comparison
• Multiple call sites scaling (5 concurrent call sites)
• Burst-then-steady-state simulating framework startup

Key result: baselineHotLoop (0.49ms) vs crossTypeInvalidationEvery1000 (467ms) = ~950x overhead

MetaclassVariationBench (9 benchmarks)

Tests GORM-like patterns where domain classes get per-instance ExpandoMetaClass enhancements:

• Shared vs per-instance metaclass dispatch
• Multi-class startup simulation (4 domain types enhanced in sequence)
• Dynamic finder calls via static metaclass injection
• Per-instance EMC with ongoing churn (worst case)

Key result: baselineSharedMetaclass (2.0ms) vs perInstanceMetaclass (420ms) = ~207x overhead

GrailsWorkloadBench (14 benchmarks)

Tests patterns extracted from the grails7-performance-regression demo app's PerformanceTestService:

• Collection closure chains (.findAll{}.collect{}.groupBy{}.collectEntries{})
• Spread operator (employees*.firstName)
• Nested closure delegation (3-level criteria-like DSL)
• GString interpolation with dynamic property access
• Dynamic property by name (this."$field")
• Project metrics aggregation (.count{}, .sum{}, map building)
• Full analysis combining all patterns

Key result: baselineCollectionClosureChain (199ms) vs with invalidation (1631ms) = ~8.2x overhead (matches demo app's observed 8.2x bootRun regression)

Running

# All new benchmarks
./gradlew :performance:jmh -PbenchInclude="CallSiteInvalidation|MetaclassVariation|GrailsWorkload"

# Individual benchmark class
./gradlew :performance:jmh -PbenchInclude=CallSiteInvalidation

Related

• GROOVY-10307
• grails-core #15293
• Demo app showing 5-8x regression
• PR GROOVY-10307: Groovy 6 - Improve invokedynamic performance with optimized caching #2377 (SwitchPoint guard optimization - benchmarked here)