RFR: Implement JEP 509: JFR CPU-Time Profiling [v46]

[Johannes Bechberger]

On Mon, 5 May 2025 12:49:00 GMT, Zhengyu Gu <zgu at openjdk.org> wrote:

>> Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix missing threads and other things
>
> src/hotspot/share/runtime/handshake.hpp line 135:
> 
>> 133:   bool can_run(bool allow_suspend, bool check_async_exception);
>> 134: 
>> 135:   bool has_operation();
> 
> `has_operation()` was an inline method, it was called from `SafepointMechanism::should_process()` (now, it calls `can_run`). I believe `SafepointMechanism::should_process()` is a latency sensitive and inlined method.

This seems to lead to a circular dependency.

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PR Review Comment: https://git.openjdk.org/jdk/pull/20752#discussion_r2073434009