8269596: Snapshot soft ref policy before marking/copying

[albertnetymk]

Set up soft ref policy before marking/copying for Serial, Parallel and G1. With this change, all collectors do soft-ref policy setup in the beginning of a GC cycle.

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Progress

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Issue

• JDK-8269596: Snapshot soft ref policy before marking/copying

Reviewers

• Thomas Schatzl (@tschatzl - Reviewer) ⚠️ Review applies to ca0e71e
• Kim Barrett (@kimbarrett - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

@albertnetymk The following label will be automatically applied to this pull request:

• hotspot-gc

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[mlbridge]

Webrevs

• 02: Full - Incremental (6ba25591)
• 01: Full - Incremental (ca0e71eb)
• 00: Full (f13bed4b)

[tschatzl]

Would it be useful to only call the soft ref policy setup via setup_policy() when it is (potentially) set to true? I.e. only during full gc, and call setup_policy(false) afterwards, maybe with a scope object?
This would remove the unnecessary calls with false as argument completely in the places where we never actually change it (e.g. for the G1 concurrent mark ref processor), and emphasize for the stw full gc collectors that they are the only ones eventually change it to "always clearing". Feel free to ignore this suggestion, but it seems unnecessary to have setup_policy(false); calls in a lot of places. Maybe if combined with below suggestion this one is obsolete.

Also the sequence

reference_processor()->enable_discovery();
reference_processor()->setup_policy(<some value>);

should be merged into a single call as there are like five places now where both are called one after another.

In psParallelCompact.cpp, the marked_for_unloading local right after these calls could be removed too, it's unused.

[albertnetymk]

Merged enable_discovery and setup_policy into one call, and made setup_policy private.

[tschatzl]

Lgtm.

[openjdk]

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

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8269596: Snapshot soft ref policy before marking/copying

Reviewed-by: tschatzl, kbarrett

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 76 new commits pushed to the master branch:

• 4107dcf: 8269466: Factor out the common code for initializing and starting internal VM JavaThreads
• 2baf498: 8269743: test/hotspot/jtreg/vmTestbase/vm/mlvm/meth/stress/jni/nativeAndMH/Test.java crash with small heap (-Xmx50m)
• 589f084: 8269110: ZGC: Remove dead code in zBarrier
• b0e1867: Merge
• a4d2a9a: 8269745: [JVMCI] restore original qualified exports to Graal
• e377397: 8268566: java/foreign/TestResourceScope.java timed out
• 6c76e77: 8260684: vmTestbase/gc/gctests/PhantomReference/phantom002/TestDescription.java timed out
• 4bbf11d: 8269580: assert(is_valid()) failed: invalid register (-1)
• 54dd510: 8269704: Typo in j.t.Normalizer.normalize()
• a8385fe: 8269354: javac crashes when processing parenthesized pattern in instanceof
• ... and 66 more: https://git.openjdk.java.net/jdk/compare/d0d26f5c550e44bf22d9155e4219351104be4635...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[albertnetymk]

I accidentally removed a call to disable_discovery(); in genCollectedHeap.cpp. Restored in the latest commit.

[kimbarrett]

Looks good.

[albertnetymk]

Thanks for the review.

/integrate

[openjdk]

Going to push as commit f8bcbf0.
Since your change was applied there have been 76 commits pushed to the master branch:

• 4107dcf: 8269466: Factor out the common code for initializing and starting internal VM JavaThreads
• 2baf498: 8269743: test/hotspot/jtreg/vmTestbase/vm/mlvm/meth/stress/jni/nativeAndMH/Test.java crash with small heap (-Xmx50m)
• 589f084: 8269110: ZGC: Remove dead code in zBarrier
• b0e1867: Merge
• a4d2a9a: 8269745: [JVMCI] restore original qualified exports to Graal
• e377397: 8268566: java/foreign/TestResourceScope.java timed out
• 6c76e77: 8260684: vmTestbase/gc/gctests/PhantomReference/phantom002/TestDescription.java timed out
• 4bbf11d: 8269580: assert(is_valid()) failed: invalid register (-1)
• 54dd510: 8269704: Typo in j.t.Normalizer.normalize()
• a8385fe: 8269354: javac crashes when processing parenthesized pattern in instanceof
• ... and 66 more: https://git.openjdk.java.net/jdk/compare/d0d26f5c550e44bf22d9155e4219351104be4635...master

Your commit was automatically rebased without conflicts.

[openjdk]

@albertnetymk Pushed as commit f8bcbf0.

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