parse rules for gen-Z support

Add parse rules for gen-Z GC with tests

[brunoborges]

/relevance-check

[github-actions]

Relevance Assessment: Likely Outdated

• Summary: The work requested in this issue — adding parse rules for Generational ZGC with tests — has been fully implemented and merged into the codebase.

• Evidence:

  • PR ZGC Generational Support #414 "ZGC Generational Support" was merged on Feb 25, 2025 by @kcpeppe. It added 2,164 lines across 31 files, including new event types (FullZGCCycle, MajorZGCCycle, MinorZGCCycle), comprehensive parsing logic, and test coverage.
  • GenZPatterns.java (133 lines) defines parse rules for Generational ZGC log formats (JDK 21+).
  • ZGCParser.java handles both legacy and generational ZGC parsing with full phase support (Y, y, O prefixes).
  • GenerationalZGCParserTest.java (709 lines) provides extensive test coverage for major and minor collection cycles, heap statistics, age tables, and reference handling.
  • Several follow-up PRs were also merged to refine the implementation: ZGC Fixes from #414 #417 (ZGC fixes), [ZGC] Add support for heap capacity, nMethod and relocation summary #426 (heap capacity/nMethod/relocation support), Fix for Legacy ZGC log files without details (-Xlog:gc) #440 (legacy no-detail fix), Report ZGC individual collections instead of cycles (#445) #447 (individual collections), Fix "No Detail" Use Cases for Legacy and Generational ZGC logging #448 (no-detail use cases), Refactored parts of the new ZGC parsing API to improve consistency #455 (API consistency refactoring).
  • The sibling issue Event support for gen-z #277 ("Event support for gen-z") in the same milestone is already closed.

• Recommendation: 🗄️ Consider closing — The parse rules for Generational ZGC have been implemented with comprehensive test coverage through PR ZGC Generational Support #414 and subsequent refinements. The remaining open issues in the "gen-Z support" milestone (gen-z parser #278, Diary enhancement for gen-z #279, gen-z support in GCToolKit #280, gen-z support in Aggregator/Aggregation #281) cover other aspects (parser wiring, diary, GCToolKit integration, aggregation) and can be tracked independently.

Generated by Relevance Check Agent for issue #276