Psst! A Sneak Peek at StableValue and SegmentMapper
summary
A JEP for StableValue is submitted and the library wraps jdk.internal.vm.annotation.@Stable to let fields and arrays change at most once, enabling JVM constant-folding while allowing deferred initialization; benchmarks show returning a constant at ~0.8ns, double-checked locking is ~2x slower and stable suppliers match constant speed, and a Fibonacci example drops from exponential to O(n) then O(1). SegmentMapper maps MemorySegment to Java records via MemoryLayout/record mappers, composes nested structs, and plans a natural layout feature.
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chapters (8)
- 0:00Introduction and motivation
- 2:29Challenges with initialization
- 10:03StableValue API overview
- 15:00StableValue implementation examples
- 20:56Benchmarks and summary
- 23:24Questions and answers
- 34:12Segment Mapper API
- 41:03Closing and final Q&A
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