Please provide hook to execute some test script on timeout. HS developers requested pstack / jstack on test hang (see comments). We are implementing it in Tonga (see CR 6504662) and it would be good to have it in jtreg too.

I suggest to add switch -ontimeout:/path/on_timeout.sh.

If it possible to implement, pass PID of test process (either java or script), though this is not absolutely required (the script could find jtreg process, it's parent and then scan entire subtree to find java processes).