RFR: 8303968: Serial: Use more precise liveness info in Young GC reference processing

Fri Mar 10 13:52:04 UTC 2023

Simple refactoring around Young-GC keep-alive-closure.

(I went for the static-local-var approach, as other solutions that I am aware of would expose the is-alive-closure in the header.)

Test: tier1-3

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Commit messages:
 - s1-ref-is-alive

Changes: https://git.openjdk.org/jdk/pull/12975/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12975&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8303968
  Stats: 15 lines in 1 file changed: 7 ins; 2 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/12975.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12975/head:pull/12975

PR: https://git.openjdk.org/jdk/pull/12975