RFR: 8209595: MonitorVmStartTerminate.java timed out [v2]

[Kevin Walls]

> From studying test failures, it looks like the way the test identifies its related processes is failing.
> It checks the mainArgs of a process by attaching, and looks like it occasionally misses getting a valid match.  The hasMainArgs method ignores exceptions as it is expecting some exceptions: it is going to test unrelated java process which happen to start.
> 
> It should retry this main args check on failure, but not too many times to be a burden on other valid unrelated processes, and should also log the PIDs that have an issue so we can see if this is part of any future failure.
> 
> Other small logging changes so we can see more easily the progress through the test.

Kevin Walls has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains six additional commits since the last revision:

 - Check main args fetching was ok.  Increase sleep.
 - nits
 - Merge remote-tracking branch 'upstream/master' into MonitorVmStartTerminate
 - nit1
 - Comment, and move takeNap() sleep method.
 - 8209595: MonitorVmStartTerminate.java timed out

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16077/files
  - new: https://git.openjdk.org/jdk/pull/16077/files/8501c23c..9b198276

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16077&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16077&range=00-01

  Stats: 22820 lines in 798 files changed: 14478 ins; 4592 del; 3750 mod
  Patch: https://git.openjdk.org/jdk/pull/16077.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16077/head:pull/16077

PR: https://git.openjdk.org/jdk/pull/16077