- From: <piranna@gmail.com>
- Date: Sun, 13 Oct 2013 18:33:58 +0200
- To: James Greene <james.m.greene@gmail.com>
- Cc: David Bruant <bruant.d@gmail.com>, Jonas Sicking <jonas@sicking.cc>, public-webapps <public-webapps@w3.org>, Glenn Maynard <glenn@zewt.org>, Andrea Marchesini <amarchesini@mozilla.com>, David Rajchenbach-Teller <dteller@mozilla.com>
- Message-ID: <CAKfGGh0XG31eAUVzZmWH0PPqYkMpmFgPUV1AdMJC+GhS+wPPoA@mail.gmail.com>
Don't know, I only know behavior of Python yield statement, but Javascript one was developed following it and I'm 90% secure it follows the same behaviour (almost all new functionalities of Javascript are being borrowed from Python since seems Mozilla Javascript implementors are Python ex-programmers in purpose) so yes, I believe it should work this way :-) El 13/10/2013 18:27, "James Greene" <james.m.greene@gmail.com> escribió: > Oh, does `yield` work anywhere? I thought it was only for use within > generators. Admittedly, I haven't been keeping up with the latest ES6 > changes. > On Oct 13, 2013 9:38 AM, "piranna@gmail.com" <piranna@gmail.com> wrote: > >> Javascript now has support for yield statements the same way Python does, >> that's a way to stop (ie. sleep) the execution of a script to allow another >> to work and restart from there. It's not their main function, but allow to >> create what's called "greenlets", green threads, and that's how I seen sync >> APIs are build in top of async ones... >> El 13/10/2013 16:21, "James Greene" <james.m.greene@gmail.com> escribió: >> >>> > a) is necessary, but for b) it is sufficient for the sync thread to be >>> > able to sleep until a condition/mutex/... is lifted >>> >>> In other words, your clarification is completely true but my initial >>> statement was written with regard to client-side JavaScript, which cannot >>> sleep. As such, I believe my original assertions are still correct with >>> regard to writing a sync wrapper in JS. >>> On Oct 13, 2013 9:09 AM, "James Greene" <james.m.greene@gmail.com> >>> wrote: >>> >>>> Thanks for adding clarification. That CAN be true but it depends on the >>>> environment [so far as I can see]. >>>> >>>> For example, such an API wrapper couldn't be built in today's >>>> client-side JavaScript because the UI thread can't do a synchronous >>>> yielding "sleep" but rather can only do a synchronous blocking wait, which >>>> means it wouldn't yield to allow for the Worker thread to asynchronously >>>> respond and toggle such a condition/mutex/etc. unless such can be >>>> synchronously requested by the blocking thread from within the busy wait >>>> loop (e.g. `processEvents();`) as browsers won't interrupt the synchronous >>>> flow of the JS busy loop to trigger `onmessage` handlers for async messages >>>> sent from the Worker. >>>> >>>> If I'm mistaken, please consider providing a code snippet, gist, etc. >>>> to get me back on track. Thanks! >>>> On Oct 13, 2013 5:06 AM, "David Rajchenbach-Teller" < >>>> dteller@mozilla.com> wrote: >>>> >>>>> On 10/12/13 3:48 PM, James Greene wrote: >>>>> > You can only build a synchronous API on top of an asynchronous API if >>>>> > they are (a) running in separate threads/processes AND (b) the sync >>>>> > thread can synchronously poll (busy loop) for the >>>>> progress/completion of >>>>> > the async thread. >>>>> >>>>> a) is necessary, but for b) it is sufficient for the sync thread to be >>>>> able to sleep until a condition/mutex/... is lifted >>>>> >>>>> >>>>> -- >>>>> David Rajchenbach-Teller, PhD >>>>> Performance Team, Mozilla >>>>> >>>>
Received on Sunday, 13 October 2013 16:34:25 UTC