> Even the current generator/yield implementations are essentially accomplished via CPS transforms.
This is untrue. Fibers uses a new stack and a long jump. Haven't looked at the implementation for generators in v8 but I'd be surprised if it was anything more exotic than a stack frame allocated on the heap and a context switch. On Mon, Aug 19, 2013 at 1:34 PM, jmar777 <[email protected]> wrote: > > I'm assuming you mean "system thread". But in effect, isn't it very much > like a green thread ? > > Async/await (or generators/yield if you prefer) are very different from > green threads. Green threads are still preemptive and managed by the VM. > Async/await, on the other hand, is basically a nice syntax addition that > allows for a more expressive form of cooperative multi-tasking. As Andrew > already said, there's nothing that you can do with async/await that you > couldn't *exactly* replicate using regular ol' callbacks. > > It's too early to say this authoritatively, but it seems that async/await > will likely sit on top of Promises; that alone should indicate that we > won't be seeing any departures from current async semantics. Even the > current generator/yield implementations are essentially accomplished via > CPS transforms. In short, preemption would be pretty devastating to > JavaScript. > > > > > On Monday, August 19, 2013 8:36:08 AM UTC-4, Floby wrote: >> >> >other functions can resume and run within the same thread >> >> I'm assuming you mean "system thread". But in effect, isn't it very much >> like a green thread ? (userspace managed ?) >> >> On Sunday, 18 August 2013 08:18:55 UTC+2, Andrew Gaspar wrote: >>> >>> On Sat, Aug 17, 2013 at 6:14 AM, Floby <[email protected]> **wrote: >>> >>>> I've read that article too. >>>> >>>> It seems to me that async/wait is a more elegant approach than twisting >>>> the yield semantics. >>>> However I don't quite see how this differs from blocking I/O calls and >>>> threads. >>>> >>>> These are cooperative threads, wihch were also an acceptable >>>> programming model in the 60's >>>> >>>> >>> Async/await doesn't block a thread. That's the point. It's *exactly*like >>> node - other functions can resume and run within the same thread while >>> another asynchronous action is being awaited. You could essentially rewrite >>> all await code to use callbacks and have the exact same functionality - it >>> just reduces code complexity. >>> >> -- > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en > > --- > You received this message because you are subscribed to the Google Groups > "nodejs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en --- You received this message because you are subscribed to the Google Groups "nodejs" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
