RFR: 8352738: Implement JEP 520: JFR Method Timing and Tracing

[Markus Grönlund]

On Mon, 19 May 2025 15:24:42 GMT, Erik Gahlin <egahlin at openjdk.org> wrote:

> Could I have a review of this enhancement that will add tracing capabilities to JFR? There are opportunities for performance improvements in the implementation, but I would rather add them later and separately.
> 
> Testing: tier 1-3, test/jdk/jdk/jfr
> 
> Thanks
> Erik

src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeSet.cpp line 502:

> 500:     }
> 501:     assert(jic.trace_id() == JfrTraceId::load_raw(jic.instance_klass()), "invariant");
> 502:     assert(HAS_STICKY_BIT(jic.instance_klass()), "invariant");

Can you replace this with "JfrTraceId::has_sticky_bit(ik)" instead? Thanks.

src/hotspot/share/jfr/support/methodtracer/jfrMethodTracer.cpp line 187:

> 185:   add_instrumented_class(ik, mp.methods());
> 186:   if (mp.has_timing()) {
> 187:     // After having installed the newly created klass into the list, perform and upcall to publish the associated TimedClass.

"perform and upcall" -> "perform an upcall" or "upcall to publish"

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PR Review Comment: https://git.openjdk.org/jdk/pull/25306#discussion_r2105220897
PR Review Comment: https://git.openjdk.org/jdk/pull/25306#discussion_r2105219553