jtreg hangs when secondary thread throws

[David Holmes]

On 17/05/2016 4:28 PM, Martin Buchholz wrote:
> Here's a minimal test with a throwing non-main thread:
>
> /* @test */
> public class YY {
>     public static void main(String[] args) throws Exception {
>         Thread t = new Thread(() -> { throw new Error(); }, "justDie");
>         t.start();
>         t.join();
>     }
> }
>
> If I run this with jtreg 4.2-b02 + jdk9+118, I get a mysterious timeout.
>
> Checking the stacks during the hang, I see no trace of YY.main (it was
> interrupted early), but I do see:
>
> "justDie" #14 prio=5 os_prio=0 tid=0x00007fb7b0001800 nid=0x230b in
> Object.wait() [0x00007fb7f1d9f000]
>    java.lang.Thread.State: TIMED_WAITING (on object monitor)
> at java.lang.Object.wait(java.base at 9-ea/Native Method)
> - waiting on <0x00000006d5613070> (a java.lang.Thread)
> at java.lang.Thread.join(java.base at 9-ea/Thread.java:1321)

It would be interesting to know what thread it is trying to join().

David
-----


> - waiting to re-lock in wait() <0x00000006d5613070> (a java.lang.Thread)
> at com.sun.javatest.regtest.agent.MainActionHelper$SameVMThreadGroup.cleanup(MainActionHelper.java:306)
> at com.sun.javatest.regtest.agent.MainActionHelper$SameVMThreadGroup.uncaughtException(MainActionHelper.java:273)
> - locked <0x00000006d5626308> (a
> com.sun.javatest.regtest.agent.MainActionHelper$SameVMThreadGroup)
> at java.lang.Thread.dispatchUncaughtException(java.base at 9-ea/Thread.java:2016)
>
> so something's gone wrong with the uncaught exception handling.
>