On Wednesday, 13 June 2018 at 09:45:04 UTC, Per Nordlöw wrote:
I've read up on Pony [1] and realized that it currently has a
superior implementation of the actor model when it comes to
combining safety, efficiency and memory management determinism
(thread-local reference-counting GC with consensus guarantees)
What libraries do we have at our disposal in D (including
code.dlang.org) for implementing task-based parallelism that is
close to Pony's solution with regards to
1. @safely sending isolated (transitively unique reference to)
messages between actors (tasks) without the need for copying.
Vibe.d has, for instance, `makeIsolated` [2] that serves this
purpose.
2. a task-scheduler that can move blocked tasks between
threads. Yes, I know, this has been discussed many times
before...I'm checking to see if there are any updates.
3. could we make such a solution GC-free by requiring immutable
data inside isolated messages to be unique references (not
currently implicitly shared) aswell using, for instance,
https://dlang.org/library/std/typecons/unique.html. I'm
thinking of a trait named something like `makeIsolatedUnshared`
that checks these restrictions.
[1] https://www.ponylang.org/
[2] http://vibed.org/api/vibe.core.concurrency/makeIsolated
What assistance can/could we currently/in-the-future get from
D's type-system to verify correctness of these paradigms?
I'm working on a library to allow @safe sharing between threads.
Originally I was just trying to write a D version of Rust's
std::sync::Mutex. It's so alpha it's not even in the dub registry
yet:
https://github.com/atilaneves/fearless
The idea is to have a @safe wrapper so the user doesn't have to
work with `shared` directly (which I call "Bring Your Own
Mutex"). I've been giving some thought to isolated data - it
really annoys in me in D that I can't send mutable data to
another threads unless I make it `shared`, even though I just
created it and will never see it again from this or any other
thread!
I need to think about how to do isolated properly. I'll look at
vibe.d for inspiration.
Atila
