ScopedValues won’t do what is needed.
Hello @loom-dev <loom-dev at openjdk.org>,
I have been enjoying the new POLLER_PER_CARRIER design in the Loom repo and I really like the direction it is going.
While building on top of the latest code, I noticed a couple of issues and would like to ask for clarification.
-
When calling Thread.startVirtualThread, the new virtual thread does not inherit the scheduler of the calling virtual thread, but instead uses DEFAULT_SCHEDULER. What is the reasoning behind this design? Could there be a mechanism to allow implicit inheritance? This would be very helpful for custom schedulers based on the per-core model.
I do not know if POLLER_PER_CARRIER works that way or not, but the preferred mechanism to get "inheritance" of values between virtual threads is to use a ScopeValue for the value and a StructuredTaskScope to organize the virtual threads.
-
The method Thread.VirtualThreadScheduler::current is very helpful, but it seems not quite enough. Since Loom already provides the read-only builtin.externalView, could we also have a method like Thread.VirtualThreadScheduler::scheduler(Thread)? This would make it easier to build better schedulers. For example, I could combine Thread.currentThread with Thread.VirtualThreadScheduler.scheduler to decide whether to push a task into a local task queue rather than the eventLoop’s MPSC queue.
Thank you for your time and help.
Best regards,
dreamlike li
regards, Rémi
|
