8371103: vmTestbase/nsk/jvmti/scenarios/events/EM02/em02t006/TestDescription.java failing

[lmesnik]

The problem happens because jvmti events are posted while handling JvmtiThreadState_lock. The fix just to move
flushing out of lock like it is already done in JvmtiEventController::set_user_enabled(..) method.

The problem start reproducing after fix for https://bugs.openjdk.org/browse/JDK-8370732 that replaced GC triggering from slow and unreliable ClassUnloader.eatMemory(); to fast and robustWhiteBox.fullGC().

The jvmti events posting is not synchronized with enabling/disabling events and setting callbacks. So even if there are new events appear in the jvmti tagmap after flushing it is not a bug to don't post them or use new callback handler.

Also, it might be makes sense to flush object events before vm_death and post all deferred events from SerrviceThread queue.
I am going to file separate RFE for this.
Also, I am going to file RFE to replace all GC provoking the eatMemory() calls with WB.fullGC() to improve test stability and reduce test execution time.

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Issue

• JDK-8371103: vmTestbase/nsk/jvmti/scenarios/events/EM02/em02t006/TestDescription.java failing (Bug - P3)

Reviewers

• Alex Menkov (@alexmenkov - Reviewer)
• Serguei Spitsyn (@sspitsyn - Reviewer)

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8371103: vmTestbase/nsk/jvmti/scenarios/events/EM02/em02t006/TestDescription.java failing

Reviewed-by: amenkov, sspitsyn

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At the time when this comment was updated there had been 25 new commits pushed to the master branch:

• 8796611: 8272160: Avoid using 32-bit counters in CDS code
• 8a0c47d: 8371225: Missing release of GDK lock in Java_sun_awt_X11_GtkFileDialogPeer_run()
• 90ccdf2: 8371367: Replace remaining JvmtiJavaThreadEventTransition with JVMTI_JAVA_THREAD_EVENT_CALLBACK_BLOCK
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[sspitsyn]

looks good.