Re: [Efficient Script Yielding] Re: [minutes] 20110706 Web Performance WG Teleconference #40

On Tue, Jul 12, 2011 at 3:07 AM, Sigbjørn Vik <sigbjorn@opera.com> wrote:

> On Thu, 07 Jul 2011 00:28:02 +0200, Jatinder Mann <jmann@microsoft.com>
> wrote:
>
>  Meeting Summary:
>>
>>
>> 3.      Feedback and discussion on the setImmediate specification
>>
>> There are a few discussions happening on the mailing list regarding
>> feedback and clarifications on the current setImmediate design, including
>> clamping, allowing the UA to delay the event, script based schedulers,
>> frequency and power consumption benefits of this API. In this call, pros and
>> cons were discussed for not clamping the setImmediate API. It was decided to
>> continue the discussion on the mailing list.
>>
>
> Should we try to find use cases for the specification before we start
> discussing the details? It would seem that how we choose to implement it
> depends on what we want it to do. I have seen several calls for the use
> cases on this list, but so far no consensus.
>
> The only use case I have seen so far is this:
> 1. Allow a script to tell the browser "If there are any other scripts to be
> executed, you may do so now, but please come back to me immediately
> afterwards (faster than a clamp would do)"
> (I do not consider working around browser bugs (e.g. frozen UI) to be real
> use cases.)
>
> If this is the main use case, it would heavily influence the clamping
> discussion. setImmediate would also be identical to setTimeout, so we could
> also consider extending setTimeout with an additional parameter: boolean
> yes_I_really_mean_the_timeout_**I_wrote
>
> I have also seen calls for a way to tell the browser "Please do all layout
> updates, and then come back to me". setImmediate does not (currently)
> address this use case, and the solution to this might end up looking quite
> different.
>
> In any case, I'd like to work out the use cases before going into the
> details of the solution.
>

I agree.  We still haven't seen any concrete use cases of pages in the wild
or of contrived, realistic test cases where setImmediate() seems to be the
right solution.  Without a clear idea of what problem or problems we're
trying to solve, it's impossible to come up with a good solution.

- James



>
> --
> Sigbjørn Vik
> Quality Assurance
> Opera Software
>
>