RFR: 8283849: AsyncGetCallTrace may crash JVM on guarantee [v9]

[Jaroslav Bachorik]

On Tue, 17 May 2022 12:52:30 GMT, Johannes Bechberger <duke at openjdk.java.net> wrote:

>> @dholmes-ora Oh, you are only objecting to the RAII mark, not to the fact that we store the state in Thread? Ok, sure. In my view, a mark prevents the "on" state from escaping the frame, e.g. if stray return calls sneak in with future changes. But I don't have strong emotions here.
>
> It would be interesting to see if it this ASGCT flag is useful in JFR, i.e. if JFR suffers potentially from the same problem. There would then be two additional places for setting this flag.

AFAIK, currently JFR is 'wrapping' the code in a crash-handler.
We can take a look at reusing this approach there in some follow-up PR but for now I would really prefer getting this one merged without attaching any more bells&whistles.

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PR: https://git.openjdk.java.net/jdk/pull/8549