[jdk17u-dev] RFR: 8293562: KeepAliveCache Blocks Threads while Closing Connections

[Goetz Lindenmaier]

I backport this for parity with 17.0.7-oracle.

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

Commit messages:
 - Backport 03f25a9c6924430ec4063b801b2b6ca55b9067c9

Changes: https://git.openjdk.org/jdk17u-dev/pull/980/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=980&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293562
  Stats: 346 lines in 3 files changed: 278 ins; 43 del; 25 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/980.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/980/head:pull/980

PR: https://git.openjdk.org/jdk17u-dev/pull/980