RFR: 8296324: JVMTI GetStackTrace truncates vthread stack trace for agents loaded into running VM [v2]

[Serguei Spitsyn]

On Fri, 18 Nov 2022 05:21:02 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

> What I believe to be the flaw here is that you call `set_notify_jvmti_events(true)`
> even if you don't call `init_static_notify_jvmti_events()`.

This only happen in a detached thread case which can be only at startup.
It was implemented this way before my fix.
The javaClasses has to be partially initialized before any call to `init_static_notify_jvmti_events()`:

void javaClasses_init() {
  JavaClasses::compute_offsets();               <== This is needed
  JavaClasses::check_offsets();
  java_lang_VirtualThread::init_static_notify_jvmti_events();
  FilteredFieldsMap::initialize();  // must be done after computing offsets.
}


For detached thread case (which is at starup) it is guaranteed that the `init_static_notify_jvmti_events()` is unconditionally called later at initialization stage. Please, see the chain of calls:
`create_vm()  => init_globals() => javaClasses_init() => java_lang_VirtualThread::init_static_notify_jvmti_events()`.

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PR: https://git.openjdk.org/jdk/pull/11204