8261759: ZGC: ZWorker Threads Continue Marking After System.exit() called

[pliden]

During JVM termination, ZCollectedHeap::stop() currently only returns once any ongoing GC cycle has completed. However, waiting for a GC cycle to complete can take awhile, so the JVM might not terminate as promptly as one might expect.

This patch adds abortion checks to workers doing marking and relocation to allow ZWorker threads to terminate promptly. In addition, before and after concurrent phases, the ZDriver thread checks if should_terminate() is true and prematurely terminates the GC cycle if that's the case.

Testing:

• Tier1-7 on Linux.
• SPECjbb2015, comparing score and marking times against baseline (5 iterations each), no difference observed.
• Ad-hoc programs calling System.exit() during marking/relocation.
• Manual Ctrl-C testing.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Issue

• JDK-8261759: ZGC: ZWorker Threads Continue Marking After System.exit() called

Reviewers

• Stefan Johansson (@kstefanj - Reviewer) ⚠️ Review applies to 53cf20a
• Albert Mingkun Yang (@albertnetymk - Committer) ⚠️ Review applies to 53cf20a

Reviewing

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[bridgekeeper]

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[openjdk]

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• hotspot-gc

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[mlbridge]

Webrevs

• 04: Full (82145e4b)
• 03: Full - Incremental (53cf20a8)
• 02: Full - Incremental (d0e6a56a)
• 01: Full - Incremental (73603d6d)
• 00: Full (cddd18e8)

[pliden]

PR updated with "Forward in-place if GC aborted" commit. This resolves a possible dead-lock during JVM shutdown where the GC has been ordered to stop/abort but there are Java threads that failed to relocate an object and are now waiting for the GC to do it for them. In this cases, we signal to all such waiters that the GC har aborted and that they should just go ahead and forward the object in-place.

[kstefanj]

Looks good, thanks for adding the comment for the macro.

[openjdk]

@pliden 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:

8261759: ZGC: ZWorker Threads Continue Marking After System.exit() called

Reviewed-by: sjohanss, ayang

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[pliden]

Thanks @albertnetymk and @kstefanj for reviewing!

/integrate

[openjdk]

@pliden Pushed as commit c3ac690.

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