RFR: 8338383: Implement JEP 491: Synchronize Virtual Threads without Pinning [v9]

[Patricio Chilano Mateo]

On Fri, 25 Oct 2024 05:17:51 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Patricio Chilano Mateo has updated the pull request incrementally with four additional commits since the last revision:
>> 
>>  - Rename set/has_owner_anonymous to set/has_anonymous_owner
>>  - Fix comments in javaThread.hpp and Thread.java
>>  - Rename nonce/nounce to seqNo in VirtualThread class
>>  - Remove ObjectMonitor::set_owner_from_BasicLock()
>
> src/hotspot/share/runtime/objectMonitor.cpp line 1673:
> 
>> 1671: 
>> 1672:   ContinuationEntry* ce = current->last_continuation();
>> 1673:   if (interruptible && ce != nullptr && ce->is_virtual_thread()) {
> 
> So IIUC this use of `interruptible` would be explained as follows:
> 
> // Some calls to wait() occur in contexts that still have to pin a vthread to its carrier.
> // All such contexts perform non-interruptible waits, so by checking `interruptible` we know 
> // this is a regular Object.wait call.

Yes, although the non-interruptible call is coming from ObjectLocker, which already has the NoPreemptMark, so I removed this check.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21565#discussion_r1817388840