8274563: jfr/event/oldobject/TestClassLoaderLeak.java fails when GC cycles are not happening

[shipilev]

This reliably fails with Serial (ignored by @requires), Shenandoah and Z:

$ CONF=linux-x86_64-server-fastdebug make run-test TEST=jdk/jfr/event/oldobject/TestClassLoaderLeak.java TEST_VM_OPTS="-XX:+UseShenandoahGC"

...

STDERR:
java.lang.RuntimeException: Could not find class leak
at jdk.test.lib.Asserts.fail(Asserts.java:594)
at jdk.jfr.event.oldobject.TestClassLoaderLeak.main(TestClassLoaderLeak.java:80)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:833)

I believe this test implicitly wants at least one GC cycle to happen so that ObjectSampler::oop_storage_gc_notification turns the sampled objects "old". An easy way to do this is to trim the Java heap size. If that does not work, we would need to go to MXBeans and watch GC cycles happening.

Additional testing:

• Affected test with -XX:+UseShenandoahGC, 10 times
• Affected test with -XX:+UseZGC, 10 times
• Affected test with -XX:+UseSerialGC, 10 times
• Affected test with -XX:+UseParallelGC, 10 times
• Affected test with -XX:+UseG1GC, 10 times

---

Progress

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Issue

• JDK-8274563: jfr/event/oldobject/TestClassLoaderLeak.java fails when GC cycles are not happening

Reviewers

• Erik Gahlin (@egahlin - Reviewer)

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (f67be26b)

[SGanguly1999]

Extremely sorry to interrupt here...But could you please tell me why we cannot call Thread.start() for the same instance of thread. I actually googled it but haven't got a satisfactory answer.
Please help me out

[shipilev]

Extremely sorry to interrupt here...But could you please tell me why we cannot call Thread.start() for the same instance of thread. I actually googled it but haven't got a satisfactory answer. Please help me out

Unfortunately, the OpenJDK PR comment, especially in the unrelated PR, is not a good place to seek general Java help. Please ask elsewhere, for example on StackOverflow.

[openjdk]

@shipilev 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:

8274563: jfr/event/oldobject/TestClassLoaderLeak.java fails when GC cycles are not happening

Reviewed-by: egahlin

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 39 new commits pushed to the master branch:

• 9573022: 8253197: vmTestbase/nsk/jvmti/StopThread/stopthrd007/TestDescription.java fails with "ERROR: DebuggeeSleepingThread: ThreadDeath lost"
• f08180f: 8274501: c2i entry barriers read int as long on AArch64
• c57ed22: 8274528: Add comment to explain an HKDF optimization in SSLSecretDerivation
• 9180d9a: 8273216: JCMD does not work across container boundaries with Podman
• 3e0d7c3: 8270290: NTLM authentication fails if HEAD request is used
• bfd6163: 8274196: Crashes in VM_HeapDumper::work after JDK-8252842
• bb95dda: 8248001: javadoc generates invalid HTML pages whose ftp:// links are broken
• 2f955d6: 8273142: Remove dependancy of TestHttpServer, HttpTransaction, HttpCallback from open/test/jdk/sun/net/www/protocol/http/ tests
• 94e31e5: 8274506: TestPids.java and TestPidsLimit.java fail with podman run as root
• a8210c5: 8274401: C2: GraphKit::load_array_element bypasses Access API
• ... and 29 more: https://git.openjdk.java.net/jdk/compare/79865cd797737f22cd4efe7e9c03ddbb86095e64...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.

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[shipilev]

Thanks @egahlin!

/integrate

[openjdk]

Going to push as commit 47bfc8a.
Since your change was applied there have been 58 commits pushed to the master branch:

• 0828273: 8274521: jdk/jfr/event/gc/detailed/TestGCLockerEvent.java fails when other GC is selected
• 6726c59: 8274634: Use String.equals instead of String.compareTo in java.desktop
• 3281102: 8268084: [macos] Disabled JMenuItem arrow is not disabled
• 7957994: 8273695: Safepoint deadlock on VMOperation_lock
• 9ca6bf0: 8274505: Too weak variable type leads to unnecessary cast in java.desktop
• 0786d8b: 8268435: (ch) ChannelInputStream could override readAllBytes
• bb4500d: 8274465: Fix javax/swing/text/ParagraphView/6364882/bug6364882.java failures
• 05d3860: 8274605: Fix predicate guarantees on returned values in (Doc)SourcePositions
• 3d7671b: 8274562: (fs) UserDefinedFileAttributeView doesn't correctly determine if supported when using OverlayFS
• c05dc26: 8274435: EXCEPTION_ACCESS_VIOLATION in BFSClosure::closure_impl
• ... and 48 more: https://git.openjdk.java.net/jdk/compare/79865cd797737f22cd4efe7e9c03ddbb86095e64...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 47bfc8a.

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