On Thu, 25 Sep 2025 21:43:46 GMT, Leonid Mesnik <[email protected]> wrote:

> The JVMTI spec says: 
> https://docs.oracle.com/en/java/javase/24/docs/specs/jvmti.html#VMDeath
> `The VM death event notifies the agent of the termination of the VM. No 
> events will occur after the VMDeath event.`
> 
> However, current implementation changes state and only after this start 
> disabling events.  
> 
> It might be not a conformance issue, because there is no way to get thread 
> state in the very beginning of event. 
> The main practical issue is that currently certain events are generated when 
> VM is becoming dead. So any function in event should check error against 
> JVMTI_PHASE_DEAD. We can easily trigger it by running tests with enabled 
> https://bugs.openjdk.org/browse/JDK-8352654
> 
> Also, it would be useful to guarantee that VM_DEATH is last event so users 
> can safely close/destroy all supported all structures used by Jvmti agent 
> (like RawMonitors).
> 
> The proposed fix is to stop events posting and wait for already executing 
> events before vm_death is posted.
> 
> Currently, I haven't seen problems with this fix and  
> https://bugs.openjdk.org/browse/JDK-8352654.

I updated the fix and description to synchronize events posting during VM 
shutdown.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/27504#issuecomment-3446990469

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