8379404: G1: Hide ConcurrentMarkThread reference from outside ConcurrentMark

[tschatzl]

Hi all,

please review this cleanup that makes the G1ConcurrentMarkThread reference of G1ConcurrentMark completely private to the latter.

Reason is that, similar to G1ConcurrentRefine this is an implementation detail, the caller is just interested in e.g. that all threads are stopped, not wanting to care about whether G1ConcurrentMark is actually initialized or how many threads it needs.

The current code had some interesting circular reference too (G1ConcurrentMark calling G1CollectedHeap´ which just went back calling G1ConcurrentMark` to do actual work).

Testing: gha

Thanks,
Thomas

---

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Issue

• JDK-8379404: G1: Hide ConcurrentMarkThread reference from outside ConcurrentMark (Enhancement - P4)

Reviewers

• Stefan Karlsson (@stefank - Reviewer)
• Ivan Walulya (@walulyai - Reviewer)

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[openjdk]

@tschatzl This change now passes all automated pre-integration checks.

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8379404: G1: Hide ConcurrentMarkThread reference from outside ConcurrentMark

Reviewed-by: stefank, iwalulya

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At the time when this comment was updated there had been 3 new commits pushed to the master branch:

• 45fc141: 8379230: JFR: Do not store leak context edge idx in markWord
• ca479be: 8379363: FontInfo improvements
• dc6f701: 8379202: Support linktime-gc on Linux with clang

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[mlbridge]

Webrevs

• 01: Full - Incremental (7a72d947)
• 00: Full (3a98fd6f)

[stefank]

This looks like a nice cleanup. One nit:

[stefank]

It looks like this addition doesn't follow the sort order.

[stefank]

Thomas explained that this is sorted case-sensitive and that we'll have a separate discussion about that outside of this PR.

[tschatzl]

Thanks @stefank @walulyai for your reviews
/integrate

[openjdk]

Going to push as commit 7101a05.
Since your change was applied there have been 19 commits pushed to the master branch:

• d6943c5: 8379193: Incorrect build ID path in SATestUtils.java
• 321bf3f: 8372273: C2: Extend the refactoring for IGV printing to include rest of the node properties
• e22c95c: 8378746: ZGC: jdk/jfr/event/gc/detailed/TestZRelocationSetGroupEvent.java intermittent OOME
• ... and 16 more: https://git.openjdk.org/jdk/compare/a2ad0809899f4f31c4bead58bcb441451403d6e8...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tschatzl Pushed as commit 7101a05.

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