Function#fork

[Hudson, Rick]

Besides web workers there are two straw man proposals that address adding parallelism and concurrency to JavaScript.

http://wiki.ecmascript.org/doku.php?id=strawman:data_parallelism and http://wiki.ecmascript.org/doku.php?id=strawman:concurrency.

The Parallel JavaScript (River Trail) proposal has a prototype implementation available at https://github.com/rivertrail/rivertrail/wiki. You should be able to implement your example's functionality using this API.

The latest HotPar https://www.usenix.org/conference/hotpar12/tech-schedule/workshop-program had two interesting papers

Parallel Programming for the Web<https://www.usenix.org/conference/hotpar12/parallel-programming-web> https://www.usenix.org/conference/hotpar12/parallel-programming-web
and
Parallel Closures: A New Twist on an Old Idea https://www.usenix.org/conference/hotpar12/parallel-closures-new-twist-old-idea

These projects each address some important part of the general problem of adding parallelism and concurrency to JavaScript.

Feedback is always appreciated.


-        Rick



From: es-discuss-bounces at mozilla.org [mailto:es-discuss-bounces at mozilla.org] On Behalf Of Jussi Kalliokoski
Sent: Monday, September 24, 2012 8:44 AM
To: es-discuss
Subject: Function#fork

Hello everyone,

I've been thinking a lot about parallel processing in the context of JavaScript, and this is really a hard problem. I'm very curious to hear what everyone's opinions are about it's problems and so forth, but I don't think an open question like that will give very interesting results, so I have an example problem for discussion (while it seems like a bad idea to me, and unlikely to ever get to the language, what I want to know is everyone's reasoning behind their opinions whether it's for or against).

What if we introduce Function#fork(), which would call the function in another thread that shares state with the current one (how much state it shares is an open question I'd like to hear ideas about, but one possibility is that only the function arguments are shared) using a similar signature to Function#call except that the first argument would be a callback, which would have error as its first argument (if the forked function throws with the given arguments, it can be controlled) and the return value of the forked function as the second argument.

 * What are the technical limitations of this?
 * What are the bad/good implications of this on the language users?
 * Better ideas?
 * etc.

I have a detailed example of showing Function#fork in action [1] (I was supposed to make a simplified test, but got a bit carried away and made it do "parallel" fragment shading), it uses a simple fill-in for the Function#fork using setTimeout instead of an actual thread.

Cheers,
Jussi

[1] https://gist.github.com/3775697
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