New Early Access builds

[August Nagro]

Appreciate the response.

I'm mostly interested in getting Vertx/Netty to work with Loom (#2). To do
so we need either continuations or custom executors for virtual threads.

I think it would deliver a ton of value. There's already solutions for
async/await on the jvm, including bytecode manipulation [1] [2] and macro
libraries [3], but Loom would be better than any of them.

[1]: https://github.com/electronicarts/ea-async
[2]: https://kotlinlang.org/docs/coroutines-overview.html
[3]: https://github.com/scala/scala-async



On Tue, Apr 5, 2022 at 4:16 PM Ron Pressler <ron.pressler at oracle.com> wrote:

> Continuations are an unsafe construct in their unrestricted form, as not
> only a lot of Java code assumes that the identity of the thread cannot be
> changed mid-method, the compiler relies on that assumption as well.
> However, continuations restricted to a single thread can be put to some
> good use, such as generators. So, to answer your question, it is possible
> that we’ll see other JDK constructs that employ continuations under the
> hood.
>
> I would note, however, that of the three examples you mentioned, the first
> is better served by virtual threads, and the second is not of interest to
> that many people if they can get their hands on virtual threads, and even
> then would often be better served by virtual threads with custom schedulers
> (which are also not in the current offering). So clearly, virtual threads
> is the application of continuations that gives the most bang for the buck,
> and other, less important, applications will be considered once we deliver
> virtual threads.
>
> — Ron
>
> > On 5 Apr 2022, at 22:46, August Nagro <augustnagro at gmail.com> wrote:
> >
> > Thanks Alan looking forward to trying it.
> >
> > Has there been any interest in adding back continuations?
> >
> > They can already be implemented with a virtual thread + lock, but having
> > more efficient access be ideal. Also, it's not always desired to suspend
> on
> > every blocking operation.
> >
> > Some use cases would be
> > - Actor Frameworks
> > - Async/Await in existing, non blocking code
> > - Generators
> >
> > On Tue, Apr 5, 2022, 11:33 AM Alan Bateman <Alan.Bateman at oracle.com>
> wrote:
> >
> >> The builds at the Project Loom Early Access page [1] have been
> >> refreshed. The latest builds are based on jdk-19+16.
> >>
> >> There aren't any API changes compared to the previous build. There are a
> >> lot of changes under hood and in particular, there are many changes in
> >> the GC and runtime areas with several important fixes. The build
> >> includes the update of ForkJoinPool that Doug Lea announced on the
> >> concurrency-interest list recently - this update improves the
> >> performance in cases such as message passing.
> >>
> >> -Alan
> >>
> >> [1] https://jdk.java.net/loom/
> >>
>
>