Claude
814c32b5ce
Basics, failure semantics on 26 vs 27, lazy collections, API across 25/26/27, preview-flag traps and a JMH read-path benchmark (jars fetched and sha1-checked, not committed). Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01TF9JWFvJSNm6HVzswzZU5a
1.3 KiB
1.3 KiB
lazy-constants — Lazy Constants (JEP 531, third preview in JDK 27)
Companion code for the ankurm.com article Lazy Constants in JDK 27 (JEP 531): Replacing Double-Checked Locking. The explanation lives in the article; this folder holds the runnable sources and the transcripts they produced.
JDK25=/path/to/jdk-25 JDK26=/path/to/jdk-26 JDK27=/path/to/jdk-27 [JDK21=/path/to/jdk-21] ./run.sh # regenerates output/*.txt
RUN_JMH=0 ./run.sh # skip the 3-minute benchmark
src/—OldWays(holder idiom and double-checked locking, plain Java),Basics,ToStringStates,Service,Failures,LazyCollections(JDK 27,--enable-preview),StableValue25(the JDK 25 API).broken/— code that fails to compile on purpose: the oldStableValuename, the two methods removed in 27, no--enable-preview, asetthat does not exist.jmh/— a JMH 1.37 benchmark of the read path../jmh/fetch.shdownloads the jars from Maven Central and checks their sha1; they are not committed../jmh/run-jmh.shwritesoutput/07-jmh.txt.
Everything except the JMH numbers is byte-stable. The JMH numbers are machine dependent: treat them as shape, not results.
Tested on Temurin 25.0.4.1+1, 26.0.2.1+1 and 27+35, and OpenJDK 21.0.10 for the plain-Java baseline.