RFR: 8304074: [JMX] Add an approximation of total bytes allocated on the Java heap by the JVM [v19]

[Paul Hohensee]

On Mon, 15 May 2023 23:12:52 GMT, Paul Hohensee <phh at openjdk.org> wrote:

>> Please review this addition to com.sun.management.ThreadMXBean that returns the total number of bytes allocated on the Java heap since JVM launch by both terminated and live threads.
>> 
>> Because this PR adds a new interface method, I've updated the JMM_VERSION to 4, but would be happy to update it to 3_1 instead.
>
> Paul Hohensee has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 26 additional commits since the last revision:
> 
>  - 8304704: _exited_allocated_bytes increment does not have to be atomic
>  - Merge branch 'master' into 8304074
>  - 8304704: _exited_allocated_bytes increment does not have to be atomic
>  - 8304704: In getTotalThreadAllocatedBytes javadoc, 'launched' -> 'started'
>  - 8304704: Typos
>  - 8304074: fetch_then_add, not fetch_and_add
>  - 8304074: Assign to _add_long_func in add_long_bootstrap
>  - Merge branch 'master' into 8304074
>  - 8304074: Define FULL_MEM_BARRIER for linux_arm
>  - 8304074: set _atomic_add_long_entry = ShouldNotCallThisStub()
>  - ... and 16 more: https://git.openjdk.org/jdk/compare/6d9db9f6...effdefc6

Makes things very much simpler without needing 64-bit atomic add. Hopefully all cleaned up.

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PR Comment: https://git.openjdk.org/jdk/pull/13814#issuecomment-1548745902