RFR: 8318058: Notify the jvm when the direct memory is oom

[Thomas Stuefe]

On Fri, 13 Oct 2023 03:23:04 GMT, xpbob <duke at openjdk.org> wrote:

> Big data processes often experience situations where the direct memory oom process is alive but not serving properly. If the direct memory is oom, code can notify the jvm. Can bring the following benefits:
> 1. Analysis of direct memory Java. Nio. DirectByteBuffer need heapdumps reference relations. Can be used directly HeapDumpOnOutOfMemoryError.
> 2. In container environment, ExitOnOutOfMemoryError can be used to let the process that cannot provide services exit, so that the container can quickly pull up a new pod

Undoubtedly useful, but there have been many discussions in the past about what does and does not constitute an OOM error, and IIRC, the stance of Oracle devs was "only if it is in java heap". Hence the missing OOM error when we cannot create threads, for instance.

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PR Comment: https://git.openjdk.org/jdk/pull/16176#issuecomment-1760881555