Re: continuation passing in Emacs vs. JUST-THIS-ONE

[Po Lu]

Jim Porter <jporterbugs@gmail.com> writes:

> On 4/17/2023 12:50 PM, Stefan Monnier wrote:
>>> This whole thread seems to echo the difference between "stackless"
>>> and
>>> "stackful" coroutines discussed in
>>> https://nullprogram.com/blog/2019/03/10/ by the author of
>>> emacs-aio,
>>> with generator-style rewriting corresponding to stackless and
>>> threads
>>> to "stackful".  So when you say "save as much as threads do", I'm
>>> not
>>> clear if you're talking about rewriting code to essentially create
>>> a
>>> heap allocated version of the same information that a thread has in
>>> the form of its stack, or something more limited like some
>>> particular
>>> set of special bindings.
>> Indeed to "save as much as threads do" we'd have to essentially
>> create
>> a heap allocated version of the same info.
>> [ I don't think that's what we want.  ]
>
> I think this subthread is about two different aspects, which is
> probably due in part to me not distinguishing the two enough
> initially; one of the reasons I'd find it useful to "save as much as
> threads do" is so that there could be a path towards packaging tasks
> up to run on another thread, and for them to eventually have enough
> context that we could run multiple packaged tasks
> *concurrently*. That's separate from a more-general asynchronous
> programming library (though they would likely interact with one
> another).
>
> Javascript might be a useful analogue here, since it too was
> originally single-threaded with an event loop, and more concurrency
> features were added in later. Similarly to "modern" JS, we could have
> async/await constructs that (primarily) work on the main thread, plus
> something similar to web workers, which operate as mostly-independent
> threads that you can communicate with via messages.

Btw, even though I don't know exactly what this is about, ISTM that
whatever you're doing could use a name that isn't missing a letter, like
`future'.  Why `futur'?