RFR: 8311218: fatal error: stuck in JvmtiVTMSTransitionDisabler::VTMS_transition_disable [v7]

[Leonid Mesnik]

On Fri, 15 Dec 2023 10:49:56 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

>> This fix is for JDK 23 but the intention is to back port it to 22 in RDP-1 time frame.
>> It is fixing a deadlock issue between `VirtualThread` class critical sections with the `interruptLock` (in methods: `unpark()`, `interrupt()`, `getAndClearInterrupt()`, `threadState()`, `toString()`), `JvmtiVTMSTransitionDisabler` and JVMTI `Suspend/Resume` mechanisms.
>> The deadlocking scenario is well described by Patricio in a bug report comment.
>> In simple words, a virtual thread should not be suspended during 'interruptLock' critical sections.
>> 
>> The fix is to record that a virtual thread is in a critical section (`JavaThread`'s `_in_critical_section` bit) by notifying the VM/JVMTI about begin/end of critical section.
>> This bit is used in `HandshakeState::get_op_for_self()` to filter out any `HandshakeOperation` if a target `JavaThread` is in a critical section.
>> 
>> Some of new notifications with `notifyJvmtiSync()` method is on a performance critical path. It is why this method has been intrincified.
>> 
>> New test was developed by Patricio:
>>  `test/hotspot/jtreg/serviceability/jvmti/vthread/SuspendWithInterruptLock`
>> The test is very nice as it reliably in 100% reproduces the deadlock without the fix.
>> The test is never failing with this fix.
>> 
>> Testing:
>>  - tested with newly added test: `test/hotspot/jtreg/serviceability/jvmti/vthread/SuspendWithInterruptLock`
>>  - tested with mach5 tiers 1-6
>
> Serguei Spitsyn has updated the pull request incrementally with one additional commit since the last revision:
> 
>   review: improve an assert message

Marked as reviewed by lmesnik (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/17011#pullrequestreview-1785514646