[webkit-dev] PSA: higher precision event timestamp landing soon - port verification needed

[Benjamin Poulain]

On Mon, Jun 10, 2013 at 5:25 PM, Rick Byers <rbyers at chromium.org> wrote:

> On Mon, Jun 10, 2013 at 5:19 PM, Benjamin Poulain <benjamin at webkit.org>wrote:
>
>> On Mon, Jun 10, 2013 at 7:37 AM, Rick Byers <rbyers at chromium.org> wrote:
>>
>>> There's been discussion / patches in the past for exposing system time
>>> as a separate timestamp on the Event object (as IE does).  See
>>> https://lists.webkit.org/pipermail/webkit-dev/2012-October/022574.html,
>>> https://bugs.webkit.org/show_bug.cgi?id=94987 and
>>> http://lists.w3.org/Archives/Public/public-web-perf/2012Oct/0046.html.
>>>
>>> In particular, the use of UNIX-epoch timestamps means such measurements
>>> will never be completely accurate (due to NTP skew, leap seconds, etc.).
>>>  But just updating the timestamp everyone uses to be more accurate (even if
>>> not perfect) seems like a clear win.
>>>
>>> Do you think both approaches should be pursued, or is updating the
>>> existing timestamp to be as accurate as possible within the epoch semantics
>>> good enough?
>>>
>>
>>  Kind of different goals in one timestamp. :)
>>
>> For input events, the accurate time delta covers many use cases. High
>> precision time would be nice but it is not really a must have.
>>
>
> Right, but isn't NTP skew a problem (at least in theory) even for accurate
> time deltas when using an epoch-based timestamp?  At least I believe that's
> part of the push back flackr@ got when he tried to plumb PlatformEvent
> timestamps into the DOM event objects a few months back.
>

Sure, I can imagine use cases where it could matter.

Benjamin
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