RFR: 8306467: Fix nsk/jdb/kill/kill001 to work with new JVMTI StopThread support for virtual threads.

[Serguei Spitsyn]

On Fri, 12 May 2023 20:58:31 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

> Currently kill001 assumes that JVMTI StopThread (via JDI ThreadReference.stop) is not supported for virtual threads. [JDK-8306034](https://bugs.openjdk.org/browse/JDK-8306034) is adding support for StopThread on a virtual thread as long as it is suspended and mounted. This means, for example, it will work for virtual threads in the following conditions:
>  - Debuggee in a loop and suspended
>  - Debuggee at a breakpoint and suspended
> 
> But will continue to not work in the following situations:
> - Debuggee in a loop but not suspended
> - Debuggee suspended but unmounted, such as during a call the Thread.sleep()
> 
> kill001 suspends all threads at a breakpoint and then does a "jdb kill" on each thread, which translate to `ThreadReference.stop()`, so this is expected to work now.
> 
> Most of the changes involve undoing the virtual thread specific code that was added to the test as part of [JDK-8282385](https://bugs.openjdk.org/browse/JDK-8282385). However, there is an additional issue that also needs fixing. The test relies on the fact that the async exception is normally not caught, and that jdb normally stops when an uncaught exception is thrown. With virtual threads there ends up being an exception handler in `java.lang.VirtualThread.run()`, resulting in jdb not stopping when the async exception is thrown. This is fixed by having the test issue a jdb "catch all <classname>" command for each async exception type that the test throws.

Looks good.
Thanks,
Serguei

test/hotspot/jtreg/vmTestbase/nsk/jdb/kill/kill001/kill001a.java line 148:

> 146:         String ThreadFinished = "Thread finished: " + this.name;
> 147:         String ThreadInterrupted = "WARNING: Thread was interrupted while waiting for killing: " + this.name;
> 148:         String CaughtExpected ="Thread " + this.name + " caught expected async exception: " + expectedException;

Nit: Space is missed after '=' sigh.

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Marked as reviewed by sspitsyn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/13967#pullrequestreview-1425258453
PR Review Comment: https://git.openjdk.org/jdk/pull/13967#discussion_r1192863515