RFR: 8349927: Waiting for compiler termination delays shutdown for 10+ ms [v2]

[Aleksey Shipilev]

> See bug for extended description. This PR reworks the shutdown waiting mechanism in three ways: 
>  1. Use exponential backoff with very small wait time at the start, to catch compiler threads earlier.
>  2. Avoid timed-wait on Monitor, when a sleep would suffice.
>  3. Track the time accurately, so we are not at the mercy of sleep/wait accuracy.
> 
> I originally found this issue when studying Leyden performance, but it affects mainline in the same way. For example, JavacBenchApp from Leyden shows we consistently save ~10ms of round-trip time:
> 
> 
> Benchmark 1: build/linux-x86_64-server-release/images/jdk/bin/java -Xmx512m -Xms512m -XX:+UseParallelGC \
>  -cp JavacBenchApp.jar JavacBenchApp 1 1
> 
> # Before
>   Time (mean ± σ):     495.4 ms ±   2.4 ms    [User: 1321.2 ms, System: 110.4 ms]
>   Range (min … max):   489.8 ms … 502.6 ms    100 runs
> 
> # After
>   Time (mean ± σ):     485.4 ms ±   2.7 ms    [User: 1318.9 ms, System: 110.3 ms]
>   Range (min … max):   479.8 ms … 494.3 ms    100 runs
> 
> 
> Additional testing:
>  - [x] Linux x86_64 server fastdebug, `tier1`
>  - [ ] Linux AArch64 server fastdebug, `all`

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Update src/hotspot/share/runtime/vmOperations.cpp
  
  Co-authored-by: David Holmes <62092539+dholmes-ora at users.noreply.github.com>

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/23593/files
  - new: https://git.openjdk.org/jdk/pull/23593/files/31696b1c..a656380a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23593&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23593&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/23593.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23593/head:pull/23593

PR: https://git.openjdk.org/jdk/pull/23593