Integrated: 8256314: JVM TI GetCurrentContendedMonitor is implemented incorrectly

[Serguei Spitsyn]

On Wed, 21 Feb 2024 10:28:49 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

> The implementation of the JVM TI `GetCurrentContendedMonitor()` does not match the spec. It can sometimes return an incorrect information about the contended monitor. Such a behavior does not match the function spec. 
> With this update the `GetCurrentContendedMonitor()` is returning the monitor only when the specified thread is waiting to enter or re-enter the monitor, and the monitor is not returned when the specified thread is waiting in the `java.lang.Object.wait` to be notified.
> 
> The implementations of the JDWP `ThreadReference.CurrentContendedMonitor` command and JDI `ThreadReference.currentContendedMonitor()` method are based and depend on this JVMTI function. The JDWP command and the JDI method were specified incorrectly and had incorrect behavior. The fix slightly corrects both the JDWP and JDI specs. The JDWP and JDI implementations have been also fixed because they use this JVM TI update. Please, see and review the related CSR and Release-Note.
> 
> CSR: [8326024](https://bugs.openjdk.org/browse/JDK-8326024): JVM TI GetCurrentContendedMonitor is implemented incorrectly
> RN:   [8326038](https://bugs.openjdk.org/browse/JDK-8326038): Release Note: JVM TI GetCurrentContendedMonitor is implemented incorrectly
> 
> Testing:
>  - tested with the mach5 tiers 1-6

This pull request has now been integrated.

Changeset: 33aa4b26
Author:    Serguei Spitsyn <sspitsyn at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/33aa4b26b190927241a81fd1cba6fe262a5b1da0
Stats:     73 lines in 10 files changed: 41 ins; 15 del; 17 mod

8256314: JVM TI GetCurrentContendedMonitor is implemented incorrectly

Reviewed-by: dholmes, lmesnik

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PR: https://git.openjdk.org/jdk/pull/17944