[jdk16] RFR: 8257215: JFR: TestRotate.java fails intermittently

[Erik Gahlin]

Hi, 

Could I have review of an intermittent product issue. It happens about 1 out of 300 the test is run.

By design, chunk files that have been parsed are deleted. Problem is that the filename could be reused, which causes issues. This happens on the server, where the files are read before they are transfered over the network, and on the client when chunks are read from the local repository. 

The logic for creating the chunk file names is now in a separate class (ChunkFilename) so it can be shared by server and client. Another problem was the clock source being used when purging files. It was not always the same as when timestamp was taken from the chunk.

Testing: Ran TestRotate.java 2100 times without failure

Testing: jdk/jdk/jfr

Thanks
Erik

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

Commit messages:
 - Cleaning up
 - Improve chunk filename
 - Initial

Changes: https://git.openjdk.java.net/jdk16/pull/131/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk16&pr=131&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8257215
  Stats: 226 lines in 14 files changed: 141 ins; 56 del; 29 mod
  Patch: https://git.openjdk.java.net/jdk16/pull/131.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk16 pull/131/head:pull/131

PR: https://git.openjdk.java.net/jdk16/pull/131