8261473: Shenandoah: Add breakpoint support

[zhengyu123]

Please review this patch that adds breakpoint support for Shenandoah, that allows Shenandoah to access a few tests:

gc/TestConcurrentGCBreakpoints.java
gc/TestJNIWeak/TestJNIWeak.java
gc/TestReferenceClearDuringMarking.java
gc/TestReferenceClearDuringReferenceProcessing.java
gc/TestReferenceRefersTo.java

The drawback is that above tests can not run with passive mode, which can result tests to hang, as breakpoints only apply to concurrent GC.

Test:

• hotspot_gc_shenandoah
• tier1 with Shenandoah

---

Progress

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

Issue

• JDK-8261473: Shenandoah: Add breakpoint support

Reviewers

• Roman Kennke (@rkennke - Reviewer) ⚠️ Review applies to 2b88f7a
• Aleksey Shipilev (@shipilev - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jdk pull/2489/head:pull/2489
$ git checkout pull/2489

[bridgekeeper]

👋 Welcome back zgu! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@zhengyu123 this pull request can not be integrated into master due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout JDK-8261473-breakpoint
git fetch https://git.openjdk.java.net/jdk master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push

[openjdk]

@zhengyu123 The following labels will be automatically applied to this pull request:

• hotspot-gc
• shenandoah

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 03: Full - Incremental (a9629c8)
• 02: Full - Incremental (4f19c4c)
• 01: Full (2b88f7a)
• 00: Full (3025a36)

[rkennke]

The change looks good to me, thanks!

[shipilev]

Looks fine, minor nits.

[shipilev]

Should probably be ShenandoahBreakpointGCScope to match that other "MarkScope".

[zhengyu123]

/integrate

[openjdk]

@zhengyu123 This PR has not yet been marked as ready for integration.

[openjdk]

@zhengyu123 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:

8261473: Shenandoah: Add breakpoint support

Reviewed-by: rkennke, shade

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 105 new commits pushed to the master branch:

• c4664e6: 8261940: Fix references to IOException in BigDecimal javadoc
• 0e9c5ae: 8075909: [TEST_BUG] The regression-swing case failed as it does not have the 'Open' button when select 'subdir' folder with NimbusLAF
• e9f3aab: 8261912: Code IfNode::fold_compares_helper more defensively
• fd098e7: 8261838: Shenandoah: reconsider heap region iterators memory ordering
• f94a845: 8261600: NMT: Relax memory order for updating MemoryCounter and fix racy updating of peak values
• 1a7adc8: 8260416: Remove unused method ReferenceProcessor::is_mt_processing_set_up()
• 3a21e1d: 8260653: Unreachable nodes keep speculative types alive
• b695c7e: 8261925: ProblemList com/sun/jdi/AfterThreadDeathTest.java on Linux
• 97e1657: 8261846: [JVMCI] c2v_iterateFrames can get out of sync with the StackFrameStream
• b8fd614: 8261939: os::strdup_check_oom() should be used in os::same_files() in os_windows.cpp
• ... and 95 more: https://git.openjdk.java.net/jdk/compare/a7726390cc00eed9833574ca716f724bd9689952...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.

[zhengyu123]

/integrate

[openjdk]

@zhengyu123 Since your change was applied there have been 105 commits pushed to the master branch:

• c4664e6: 8261940: Fix references to IOException in BigDecimal javadoc
• 0e9c5ae: 8075909: [TEST_BUG] The regression-swing case failed as it does not have the 'Open' button when select 'subdir' folder with NimbusLAF
• e9f3aab: 8261912: Code IfNode::fold_compares_helper more defensively
• fd098e7: 8261838: Shenandoah: reconsider heap region iterators memory ordering
• f94a845: 8261600: NMT: Relax memory order for updating MemoryCounter and fix racy updating of peak values
• 1a7adc8: 8260416: Remove unused method ReferenceProcessor::is_mt_processing_set_up()
• 3a21e1d: 8260653: Unreachable nodes keep speculative types alive
• b695c7e: 8261925: ProblemList com/sun/jdi/AfterThreadDeathTest.java on Linux
• 97e1657: 8261846: [JVMCI] c2v_iterateFrames can get out of sync with the StackFrameStream
• b8fd614: 8261939: os::strdup_check_oom() should be used in os::same_files() in os_windows.cpp
• ... and 95 more: https://git.openjdk.java.net/jdk/compare/a7726390cc00eed9833574ca716f724bd9689952...master

Your commit was automatically rebased without conflicts.

Pushed as commit 9cf4f90.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.