8243452: JFR: Could not create chunk in repository with over 200 recordings

[Erik Gahlin]

Hi,

Could I have a review of this.

The problem occurs when more than 100 chunks are created per second and 
there is a fallback to generate the file path using 
System.currentMillis(). That code path was never executed before and 
there is no need to use toRealPath(). It can simply return the path p, 
as in normal circumstances. Not sure why it fails with an exception 
(which causes the JVM to exit).

Bug:
https://bugs.openjdk.java.net/browse/JDK-8243452

Webrev:
http://cr.openjdk.java.net/~egahlin/8243452/

Testing: jdk/jdk/jfr and reproducer with 2000 chunks.

Thanks
Erik