On Mon, 19 Apr 2021 04:43:15 GMT, David Holmes <[email protected]> wrote:
>> Robbin Ehn has updated the pull request incrementally with one additional
>> commit since the last revision:
>>
>> Fixed nits
>
> src/hotspot/share/runtime/handshake.hpp line 157:
>
>> 155: Thread* active_handshaker() const { return _active_handshaker; }
>> 156:
>> 157: // Suspend/resume support
>
> Taking a step back I can't help but think that this is entirely the wrong
> place to have the suspend/resume API and supporting code. It is only here
> because we re-use the HandshakeState _lock monitor right? If we introduced a
> new thread-suspension monitor instead then this code would all reside
> somewhere else - probably in the JavaThread class.
When going to blocked inside the async handshake we **must** unlock the
HandshakeState lock.
Thus _lock.wait() unlocks and gives us something to notify.
We could do:
_lock.unlock();
{
MutexLocker(SomeOtherLock) ml;
SomeOtherLock.wait();
}
_lock.lock();
Another alternative is to create a friend class which uses the HandshakeState
lock and having the API there instead.
-------------
PR: https://git.openjdk.java.net/jdk/pull/3191
