RFR: 8352251: Implement JEP 518: JFR Cooperative Sampling [v23]

[Markus Grönlund]

On Thu, 15 May 2025 23:04:38 GMT, Markus Grönlund <mgronlun at openjdk.org> wrote:

>> Another case we are missing is when we freeze. We should call `Jfr::check_and_process_sample_request` before copying the frames to the heap.
>
> The check, or some version of it, is already in place.
> 
> Please check in JfrStackTrace.cpp:
> 
> if (method->intrinsic_id() == vmIntrinsicID::_Continuation_enterSpecial) {
>     assert(JfrThreadLocal::is_vthread(jt), "invariant");
>     const ContinuationEntry* const cont_entry = jt->last_continuation();
>     assert(cont_entry != nullptr, "invariant");
>     return cont_entry->is_virtual_thread();
>   }

> Another case we are missing is when we freeze. We should call `Jfr::check_and_process_sample_request` before copying the frames to the heap.

Where do you suggest to place it best?

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PR Review Comment: https://git.openjdk.org/jdk/pull/24296#discussion_r2092078968