[jdk17] RFR: 8271251: JavaThread::java_suspend() fails with "fatal error: Illegal threadstate encountered: 6" [v3]

[Vladimir Kozlov]

On Mon, 26 Jul 2021 22:40:53 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> Hi,
>> 
>> Please review this small patch. When self-suspending, a JavaThread might reach SafepointSynchronize::block() with a state of _thread_in_vm which is not listed as a valid state for safepoint polling. There are a couple of simple ways to fix this. As suggested by @dholmes-ora  we can avoid the handshake machinery altogether and directly self-suspend. Since this issue is intermittent and in tier7 which I didn't run as many times as other lower tiers it escaped my testing of 8270085.
>> 
>> Testing in mach5 tiers1-7. I also reproduced the test failures locally and verified that now both hs202t002.java and ThreadSuspendSelf.java are passing. 
>> 
>> Thanks,
>> Patricio
>
> Patricio Chilano Mateo has updated the pull request incrementally with one additional commit since the last revision:
> 
>   move log statement back inside loop

Note, currently you need to get approval for JDK 17 fix according to: 
http://openjdk.java.net/jeps/3#Fix-Request-Process

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PR: https://git.openjdk.java.net/jdk17/pull/283