RFR: Implement JEP 509: JFR CPU-Time Profiling [v45]

[Johannes Bechberger]

On Mon, 5 May 2025 12:52:09 GMT, Zhengyu Gu <zgu at openjdk.org> wrote:

>> You're right. But this seems to be an inherent problem of stacks. I'm going to use the previous lockless queue implementation for the fresh frames queue. The problem should not occur with the thread-local queues though?
>
> Hotspot does have an implementation of [lock free stack]( https://github.com/openjdk/jdk/blob/master/src/hotspot/share/utilities/lockFreeStack.hpp), but you have to deal with ABA problem.

Which is not array based and therefore not usable in signal handlers.

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PR Review Comment: https://git.openjdk.org/jdk/pull/20752#discussion_r2073420361