RFR: 8319206: [REDO] Event NativeLibraryLoad breaks invariant by taking a stacktrace when thread is in state _thread_in_native

[David Holmes]

On Wed, 1 Nov 2023 11:12:41 GMT, Markus Grönlund <mgronlun at openjdk.org> wrote:

> Greetings,
> 
> The original problem was introduced with:
> 
> [JDK-8313251](https://bugs.openjdk.org/browse/JDK-8313251) - Add NativeLibraryLoad event
> 
> The first attempt at resolution:
> 
> [JDK-8315220](https://bugs.openjdk.org/browse/JDK-8315220) - Event NativeLibraryLoad breaks invariant by taking a stacktrace when thread is in state _thread_in_native
> 
> was reverted:
> 
> [JDK-8315930](https://bugs.openjdk.org/browse/JDK-8315930) - Revert "8315220: Event NativeLibraryLoad breaks invariant by taking a stacktrace when thread is in state _thread_in_native"
> 
> because it ran into:
> 
> [JDK-8315892](https://bugs.openjdk.org/browse/JDK-8315892) - NativeLibraryLoadEvent dtr fails with "assert(false) failed: Possible safepoint reached by thread that does not allow it"
> 
> The reason for [JDK-8315892](https://bugs.openjdk.org/browse/JDK-8315892) was that the thread loading the zip library, in thread state native, was the owner of the Zip_lock mutex. This prevented it from transitioning to thread_in_vm.
> 
> The Zip_lock mutex was removed as part of:
> 
> [JDK-8317951](https://bugs.openjdk.org/browse/JDK-8317951) - Refactor loading of zip library to help resolve [JDK-8315220](https://bugs.openjdk.org/browse/JDK-8315220)
> 
> Therefore, it is time to redo the original [JDK-8315220](https://bugs.openjdk.org/browse/JDK-8315220), now under this issue, [JDK-8319206](https://bugs.openjdk.org/browse/JDK-8319206).
> 
> Testing: jdk_jfr, tiers1-6, stress testing
> 
> Thanks
> Markus

General runtime changes seem fine. I can't comment on all the JFR-specific aspects but in general that appears okay too.

Thanks

-------------

Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/16447#pullrequestreview-1709536385