Add compact-strings module: Compact Strings (JEP 254) measured with JOL on JDK 25, with and without -XX:-CompactStrings, and compact object headers on 25 vs 27

Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01KqJyCidz3ZgRyHABv2GVJh
2026-10-01 04:23:27 +00:00
parent fadfd05670
commit fc05eed4b5
26 changed files with 943 additions and 0 deletions
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+$ java -Xmx3g -XX:-UseCompactObjectHeaders MillionStrings      (JDK 27)
+java.version = 27
+strings                      : 1,000,000 (average 42.50 chars)
+coder == 0 (LATIN1) in set A : 1,000,000
+coder == 1 (UTF16)  in set B : 1,000,000
+# WARNING: Unable to attach Serviceability Agent. sun.jvm.hotspot.runtime.VM.isCompressedKlassPointersEnabled()
+A: lower-case ASCII only     : 89,844,680 bytes  (89.8 MB, 89.8 bytes per string)
+B: same + one euro sign      : 133,839,824 bytes  (133.8 MB, 133.8 bytes per string)
+B / A                        : 1.490