[jdk11u-dev] RFR: 8213137: Remove static initialization of monitor/mutex instances

[Evgeny Astigeevich]

On Wed, 9 Jun 2021 19:48:52 GMT, Evgeny Astigeevich <github.com+42899633+eastig at openjdk.org> wrote:

> We are backporting JDK-8210832: Remove sneaky locking in class Monitor. It has a few dependencies. JDK-8213137: Remove static initialization of monitor/mutex instances is one of them.
> 
> The original patch from JDK-8213137 causes conflicts. The conflicts are because a patched file does not exist in jdk11u and git struggled to position changes. The original changes are not changed after resolution of the conflicts.
> 
> Testing: Amazon Linux 2, aarch64, tier1 and tier2. Amazon Linux 2, x86_64, tier1 and tier2.

Thanks Xin for reviewing.

According to [JDK-8213137 comment](https://bugs.openjdk.java.net/browse/JDK-8213137?focusedCommentId=14220303&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14220303) changes to parallelCleaning.hpp and parallelCleaning.cpp need [JDK-8209189](https://bugs.openjdk.java.net/browse/JDK-8209189) which removes uses of `CodeCacheUnloadingTask::_lock`.
According to [JDK-8209189](https://bugs.openjdk.java.net/browse/JDK-8209189) its changes are needed for ZGC  which is experimental in java 11. So there is no need to backport [JDK-8209189](https://bugs.openjdk.java.net/browse/JDK-8209189) to java 11.

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PR: https://git.openjdk.java.net/jdk11u-dev/pull/21