Companion module for the rewritten post 'Virtual Threads on Spring Boot 4.1: The Benchmarks, Re-Run, and the Pinning Advice That Expired', retitled and re-benchmarked on Boot 4.1.1 / JDK 25.0.4.1 (the original post was written against Boot 3.4 / JDK 21). Covers: I/O-bound and CPU-bound throughput (platform vs virtual threads, including a JIT-warmup benchmarking bug this build caught and fixed), JEP 491 proof that synchronized no longer pins a virtual thread's carrier across a blocking call as of JDK 24 (obsoleting the old avoid-synchronized advice), proof that -Djdk.tracePinnedThreads=full is inert on JDK 25, and JEP 506's finalized ScopedValue API (JDK 25 GA, no --enable-preview, and a different shape than the old preview API). Kept as its own module rather than a new top-level repository, alongside the existing async/ module, which already has a stronger dual-JDK JEP 491 proof that this module's docs cross-link to instead of duplicating.
10 lines
512 B
Plaintext
10 lines
512 B
Plaintext
JEP 491 proof: synchronized held across Thread.sleep, JDK 25.0.4.1
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==================================================================
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availableProcessors (default virtual-thread carrier pool size) = 2
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virtual threads = 60, each holds a DISTINCT monitor for 250ms
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predicted wall time IF PINNED (pre-JDK-24 behaviour): ~7500ms
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predicted wall time IF NOT PINNED (JDK 24+ behaviour): ~250ms, independent of carrier count
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actual wall time: 251ms
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verdict: NOT PINNED -- matches JEP 491's documented JDK 24+ behaviour
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