[jdk8u-dev] RFR: 8293562: KeepAliveCache Blocks Threads while Closing Connections

[Dhamoder Nalla]

Issue:  [JDK-8293562](https://bugs.openjdk.org/browse/JDK-8293562): KeepAliveCache Blocks Threads while Closing Connections

Backport of PR https://github.com/openjdk/jdk11u-dev/pull/1890  fromJDK11 to JDK8.

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

Commit messages:
 - Backport 770c1f65c588f3156f9b70097df752d8059c1038

Changes: https://git.openjdk.org/jdk8u-dev/pull/402/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=402&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293562
  Stats: 401 lines in 3 files changed: 302 ins; 36 del; 63 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/402.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/402/head:pull/402

PR: https://git.openjdk.org/jdk8u-dev/pull/402