RFR: 8349787: java/lang/Thread/virtual/ThreadPollOnYield.java#default passes unexpectedly without libVThreadPinner.so [v3]

[SendaoYan]

> Hi all,
> 
> Test test/jdk/java/lang/Thread/virtual/ThreadPollOnYield.java run passed unexpected without native library or with the incorrect native library path. The test command with incorrect native library path shows below. We will seen this tests run passed unexpected before this PR, because the first virtual thread do not run normally without the dependent shared library libVThreadPinner.so, and there is no assert when the first virtual thread run abnormal.
> 
> 
> mkdir -p empty-directory ; jtreg -v:fail,error -w tmp -nr -jdk:build/linux-x86_64-server-release/images/jdk -nativepath:empty-directory test/jdk/java/lang/Thread/virtual/ThreadPollOnYield.java#default
> 
> 
> This PR add a latch variable will make sure the first virtual thread run once at least. After this PR run the same test command which with incorrect native library path, and we will seen this pass run timed out as expected.
> 
> Change has been verified locally, test-fix only, no risk.

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

  Rename latch to started, and do the countDown before the while loop

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23576/files
  - new: https://git.openjdk.org/jdk/pull/23576/files/12f069c1..341eae9a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23576&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23576&range=01-02

  Stats: 4 lines in 1 file changed: 1 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/23576.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23576/head:pull/23576

PR: https://git.openjdk.org/jdk/pull/23576