RFR: 8352256: ObjectSynchronizer::quick_notify misses JFR event notification path [v3]

[Markus Grönlund]

On Thu, 20 Mar 2025 08:39:54 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> > That said it is not clear to me that posting the event doesn't violate the requirements that the quick version must maintain: no safepoints, no blocking, no state transitions. ??
> 
> Huh, that's a good question. There is a `NoSafepointVerifier` at the beginning `ObjectSynchronizer::quick_notify`, so at least the mechanical runtime checks did not fail. I'll run `all` tests with monitor notification event enabled.
> 
> I clicked through the JFR event commit code, and I don't think there are safepoints, indefinite blocking, or state transitions. Can we rely on this, @egahlin, @mgronlun?

A JavaThread in state VM or Java running the JFR commit code will not perform a transition or block for a safepoint. It is not waitfree (yet) however because of the JfrStacktrace_lock.

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PR Comment: https://git.openjdk.org/jdk/pull/24097#issuecomment-2777993670