RFR: 8371014: Dump JFR recording on CrashOnOutOfMemoryError is incorrectly implemented

[Markus Grönlund]

On Wed, 7 Jan 2026 17:45:55 GMT, Markus Grönlund <mgronlun at openjdk.org> wrote:

>> TestEmergencyDumpAtOOM.java has passed on both, AIX and linux on PPC64. Thanks!
>
>> TestEmergencyDumpAtOOM.java has passed on both, AIX and linux on PPC64. Thanks!
> 
> Thanks Martin.

> Thanks a lot @mgronlun ! Looks good in general.
> 
> Can we wait to finish `service.emit_leakprofiler_events()` in JFR recorder thread before the crash at `report_java_out_of_memory()` in debug.cpp? whether `abort()` is called before finishing to dump events by recorder thread.

The solution to is avoid someone calling abort() concurrently until at least one service.emit_leakprofiler_events(); has completed. That's why the invocation is done by all threads coming into report_java_out_of_memory(), not only a cas-selected one. Why?

Because it is only by taking the threads from thread state _thread_in_vm to state _thread_blocked (which we manage as part of posting the JFR msg), that a VM operation in service.emit_leakprofiler_events() can proceed.

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PR Comment: https://git.openjdk.org/jdk/pull/29094#issuecomment-3723611490