RFR: JDK-8286789: Test forceEarlyReturn002.java timed out [v2]

[Alex Menkov]

> This is an attempt to fix suspicious code in the forceEarlyReturn002.java and un-problemlist it to see if the problem appear again.
> 
> The test fails in "virtual thread factory" mode with timeout for unclear reason after it finished testing and performs cleanup process (debugger sends debuggee a command to exit, but debuggee doesn't receive the command).
> This is the only test which has this intermittent communication failures.
> The test was problem-listed, I was not able to reproduce the issue with 1000+ runs.
> 
> Debuggee creates a thread which executes tight infinite loop in native code (in "virtual thread factory" mode it's pinned virtual thread).
> The fix adds delays in the loop and adds new command to exit from native method after testing.
> 
> Testing: 100 runs in "virtual thread factory" mode on all Oracle supported platforms.

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

  use atomic instead of volatile

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15301/files
  - new: https://git.openjdk.org/jdk/pull/15301/files/3c1d0d31..0dbbe0dc

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15301&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15301&range=00-01

  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/15301.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15301/head:pull/15301

PR: https://git.openjdk.org/jdk/pull/15301