RFR: 8327799: JFR view: the "Park Until" field of jdk.ThreadPark is invalid if the parking method is not absolute

[Erik Gahlin]

On Tue, 12 Mar 2024 06:27:56 GMT, Long Yang <lyang at openjdk.org> wrote:

> Hi all
> 
> Could I have a review of this patch for [JDK-8327799](https://bugs.openjdk.org/browse/JDK-8327799)?
> 
> 
> UNSAFE.park(true, System.currentTimeMillis() + 1000);
> UNSAFE.park(false, 2000L * 1000 * 1000);
> 
> 
> 
> jfr view jdk.ThreadPark test.jfr
> 
>                                                     Java Thread Park
> Start Time Duration Event Thread Stack Trace             Class Parked On Park Timeout Park Until Address of Object Pa...
> ---------- -------- ------------ ----------------------- --------------- ------------ ---------- -----------------------
> 20:13:21     1.00 s main         jdk.internal.misc.Un... N/A                      N/A 20:13:22   0x00000000
> 20:13:22     2.00 s main         jdk.internal.misc.Un... N/A                   2.00 s 08:05:43   0x00000000
> 
> 
> If the parking method is not absolute (the second event), the real value of "until" in JFR event is `Long.MIN_VALUE`, which will be convert back to `java.time.Instant.MIN`, but `JFR view` displays this value as '08:05:43' of my timezone. This is somewhat misleading, better to show as `N/A`, just like what `jfr print --events` does.
> 
> Testing:
> test/jdk/jdk/jfr/tool/TestView.java
> test/jdk/jdk/jfr/jcmd/TestJcmdView.java
> 
> All passed.
> 
> Thanks

Marked as reviewed by egahlin (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/18214#pullrequestreview-1930531808