java/nio/file/Files/InterruptCopy.java test fails due to thread cleanup issue

intermittent failure on Windows during MACH5 Windows SBR test runs

test has launched a copy thread (via ScheduledExecutor) and a background has been launched to execute the copy, while the executor thread waits for completion.
The copy is cancelled by invoking cancel on the returned Future.
The tested scenarios appear to be successful.

but the cancel doesn't seem to have reached the background threads involved in the copy waltz, for the cancel and interrupt don't seem to have terminated those threads or they are not being reaped.




JavaTest Message: Test complete.


JavaTest Message: Problem cleaning up the following threads:
pool-3-thread-1
  at java.base@18-ea/java.lang.Object.wait(Native Method)
  at java.base@18-ea/java.lang.Thread.join(Thread.java:1304)
  at java.base@18-ea/java.lang.Thread.join(Thread.java:1372)
  at java.base@18-ea/sun.nio.fs.Cancellable.runInterruptibly(Cancellable.java:125)
  at java.base@18-ea/sun.nio.fs.WindowsFileCopy.copy(WindowsFileCopy.java:197)
  at java.base@18-ea/sun.nio.fs.WindowsFileSystemProvider.copy(WindowsFileSystemProvider.java:284)
  at java.base@18-ea/java.nio.file.Files.copy(Files.java:1305)
  at InterruptCopy$2.call(InterruptCopy.java:139)
  at InterruptCopy$2.call(InterruptCopy.java:134)
  at java.base@18-ea/java.util.concurrent.FutureTask.run(FutureTask.java:264)
  at java.base@18-ea/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304)
  at java.base@18-ea/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
  at java.base@18-ea/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
  at java.base@18-ea/java.lang.Thread.run(Thread.java:833)

NIO-Task
  at java.base@18-ea/sun.nio.fs.WindowsNativeDispatcher.CopyFileEx0(Native Method)
  at java.base@18-ea/sun.nio.fs.WindowsNativeDispatcher.CopyFileEx(WindowsNativeDispatcher.java:314)
  at java.base@18-ea/sun.nio.fs.WindowsFileCopy$1.implRun(WindowsFileCopy.java:189)
  at java.base@18-ea/sun.nio.fs.Cancellable.run(Cancellable.java:95)
  at java.base@18-ea/java.lang.Thread.run(Thread.java:833)

----------System.out:(9/265)----------
Checking space ((C:))
Creating source file...
Source file created.
Copying file at 1635437763359 ms...
Interrupting at 1635437763410 ms...
Copy failed (this is expected).
Copying file at 1635437770936 ms...
Cancelling at 1635437770951 ms...
Copy cancelled.
result: Error. Error while cleaning up threads after test


test result: Error. Error while cleaning up threads after test