RFR: 8369442: ExitOnOutOfMemoryError should exit more gracefully [v2]

[Axel Boldt-Christmas]

On Fri, 10 Oct 2025 06:12:42 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> See RFE for more discussion. It seems we have a leeway in defining what "exit" means for `-XX:+ExitOnOutOfMemoryError`, and this PR does it more akin to `JVM_Halt`, rather than abrupt `os::_exit`. This gives VM a chance to shutdown some of its subsystems gracefully.
>> 
>> Comments welcome!
>> 
>> Additional testing:
>>  - [x] Linux x86_64 server fastdebug, `tier1`
>>  - [ ] Linux x86_64 server fastdebug, `all`
>
> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update src/hotspot/share/utilities/debug.cpp
>   
>   Co-authored-by: David Holmes <62092539+dholmes-ora at users.noreply.github.com>

Are we sure that `before_exit` can handle being called at any point between `set_init_completed` and when we start running user byte code. 

I know we have internally questioned the validity of the development flag `ExitOnFullCodeCache` which also can call `before_exit` very early, albiet it uses the non-halting version which is scarier.

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PR Comment: https://git.openjdk.org/jdk/pull/27718#issuecomment-3388789658