RFR: 8320304: Refactor and simplify monitor deflation functions [v2]

[Daniel D. Daugherty]

On Mon, 20 Nov 2023 20:31:14 GMT, Daniel D. Daugherty <dcubed at openjdk.org> wrote:

>> Good point. This code is going to be rewritten for https://bugs.openjdk.org/browse/JDK-8319137 and https://bugs.openjdk.org/browse/JDK-8319048. The comment here https://github.com/openjdk/jdk/pull/16412#issuecomment-1818358260 is a suggestion for how to solve both issues, and I think it should include the fixes to the logging.
>
> The call to `log.before_blocked()` on L1725 will stop the timer so it will not
> be running during the ThreadBlockInVM.
> The call to `log.after_blocked()` on L1731 will restart the timer.
> The advantage of having these two calls is that you know how long we spent
> in ThreadBlockInVM based on the timestamps in the two log mesgs.

Definitely going to have to merge with [JDK-8319137](https://bugs.openjdk.org/browse/JDK-8319137)!!

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PR Review Comment: https://git.openjdk.org/jdk/pull/16706#discussion_r1399725241