RFR: 8262454: Handshake timeout improvements, single target, kill unfinished thread

[Patricio Chilano Mateo]

On Fri, 26 Feb 2021 10:48:14 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

> When executing a single target handshake we do not have a timeout.
> When we timeout we should crash the thread with the non-completed handshake operation.
> 
> VM_Handshake only had one implementer so I remove it.
> 
> Passes t1-5.

Looks good!

test/hotspot/jtreg/runtime/handshake/HandshakeTimeoutTest.java line 83:

> 81:             int i = 0;
> 82:             while (true) {
> 83:                 i++;

Are we relying on the fact that the timeout is small (1ms) and so at some point one of the HandshakeALotClosure operations should timeout? 
Otherwise you could do as in TestAbortVMOnSafepointTimeout.java and use "wb.waitUnsafe(waitTime)" so that it will timeout right away.

-------------

PR: https://git.openjdk.java.net/jdk/pull/2743