Javascript Defer

It would be nice to have a browser native delay function that added 
a function to the call stack to be run immediately, but not blocking 
UI, similar to 

> setTimeout(func, 0).

Currently prototype does this - prototype.function.defer sets a 
timeout of 0.01.

In my experience though, setting a timeout has a delay - Resig's 
experiments seem to confirm: 
> http://ejohn.org/blog/analyzing-timer-performance/

It'd be nice if 
> window.defer(func)
 was isomorphic to
> window.setTimeout(func, 0.01) 
so that older browsers could be supported, but code ran much faster 
with the defer code.

Is this a good idea? Is there a way to do this currently?

Mr. Braden,

You're right -- setTime(func, 0) runs between 5-20ms later (or something, depending on browser). Ben posted an article about it similar to Resig's but with updated numbers: http://www.adequatelygood.com/2010/2/Minimum-Timer-Intervals-in-JavaScript

Your basic goal is background processing? I remember seeing something about worker threads coming to an HTML5 implementation near you, but they're not widely supported yet...

http://blog.mozbox.org/post/2009/04/10/Web-Workers-in-action
http://www.ajaxwith.com/JavaScript-Worker-Threads.html

Please enjoy my near-zero contribution to this conversation :)

Mr Boehmer,

Thanks - I hadn't realised Ben had investigated the delay.

I've played with worker threads, and whilst pretty cool, they're a hassle to implement because of the message passing.

The goal with this would be to stop the browser locking up on large loops - I find myself reimplementing the same chunk processing code and then trying to tune the timeout to be as quick as possible. Ideally I could just pass an iterable to a map function, and using this delay function it would ensure that the loop doesn't block the browser's thread.

So not as much background processing as splitting up foreground processing.

P

Mr Boehmer,

Thanks - I hadn't realised Ben had investigated the delay.

I've played with worker threads, and whilst pretty cool, they're a hassle to implement because of the message passing.

The goal with this would be to stop the browser locking up on large loops - I find myself reimplementing the same chunk processing code and then trying to tune the timeout to be as quick as possible. Ideally I could just pass an iterable to a map function, and using this delay function it would ensure that the loop doesn't block the browser's thread.

So not as much background processing as splitting up foreground processing.

P