RFR: 8267926: AsyncLogGtest.java fails on assert with: decorator was not part of the decorator set specified at creation. [v2]

[Xin Liu]

> The root cause of the intermittent failure is that _decorators in LogDecorations 
> may be inconsistent with LogOutput::_decorators. It could happen when gtest disables a
> Log output via set_log_config(TestLogFileName, "all=off").
> 
> Since we copy the entire logDecorations, it's reasonable to copy _decorator as well. 
> LogDecorator is a bitmask of uiint. It's even smaller than a reference on LP64 platforms.
> 
> Caveat: this patch doesn't fix the race condition of update_decorators. Theorically,
> it may still cause an error if user dynamically enrich decorators for one log output. 
> User can't do that via dcmd VM.log because one can't change the configuration of 
> an established output via dcmd.

Xin Liu has updated the pull request incrementally with one additional commit since the last revision:

  8267926: AsyncLogGtest.java fails on assert with: decorator was not part of the decorator set specified at creation.

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4257/files
  - new: https://git.openjdk.java.net/jdk/pull/4257/files/0bde2876..5ad232b2

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4257&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4257&range=00-01

  Stats: 98 lines in 6 files changed: 92 ins; 4 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4257.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4257/head:pull/4257

PR: https://git.openjdk.java.net/jdk/pull/4257