RFR: 8243962: Various JVM TI tests time out using JFR on Windows [v2]

[Markus Grönlund]

> Greetings,
> 
> JDK-8243962 has been a large effort to chase down intermittent timeouts for certain JVMTI tests when run on Windows
> debug builds in combination with JFR. The background is long, included in JDK-8243962.
> In short, the combination of some JVMTI thread suspension tests when run together with JFR on saturated Windows 2016
> debug builds can intermittently time out.
> There have been two major changes made to JFR derived from JDK-8243962 (linked therein) in an attempt to reduce the
> poor scalability observed.
> Unfortunately, the efforts have not fully resolved the situation entirely as there have still been intermittent
> sightings for the following tests:
> vmTestbase/nsk/jvmti/scenarios/sampling/SP04/sp04t002/TestDescription.java
> vmTestbase/nsk/jvmti/scenarios/sampling/SP04/sp04t001/TestDescription.java
> vmTestbase/nsk/jvmti/scenarios/sampling/SP03/sp03t001/TestDescription.java
> vmTestbase/nsk/jvmti/scenarios/sampling/SP03/sp03t002/TestDescription.java
> 
> This change will add a requires expression to these tests to exclude the combination of running them with JFR on
> Windows debug builds.
> Thanks
> Markus

Markus Grönlund 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 three additional commits since
the last revision:

 - deMorgan
 - Merge branch 'master' into 8243962
 - 8243962: Various JVM TI tests time out using JFR on Windows

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/712/files
  - new: https://git.openjdk.java.net/jdk/pull/712/files/4f899253..cf381fcc

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=712&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=712&range=00-01

  Stats: 162 lines in 21 files changed: 95 ins; 32 del; 35 mod
  Patch: https://git.openjdk.java.net/jdk/pull/712.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/712/head:pull/712

PR: https://git.openjdk.java.net/jdk/pull/712