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RE: [HighResolutionTime] comments on performance.now

From: Jatinder Mann <jmann@microsoft.com>
Date: Wed, 11 Apr 2012 16:17:47 +0000
To: Simon Pieters <simonp@opera.com>, "public-web-perf@w3.org" <public-web-perf@w3.org>
Message-ID: <EE4C13A1D11CFA49A58343DE361B0B041775F972@TK5EX14MBXC253.redmond.corp.microsoft.com>
>This might not be a problem in the majority of cases, but I've been told that at least a few years ago some 
>cases was no better than 10ms resolution (maybe it wasn't a hardware limitation but a limitation somewhere 
>else). This is apparently mostly changed today, but I still think the spec shouldn't say to do something impossible 
>when facing underlying limitations. (For instance, timer resolution might be reduced intentionally to not drain the battery.)

I have updated the definition to include a SHOULD clause in returning microsecond resolution on millisecond units. I have also added a note that suggests UA should fallback to millisecond resolution on millisecond units when they have hardware or software constraints on providing a sub-millisecond resolution.

>> I don't understand why we wouldn't want to include the time of 
>> suspension - performance.now() defines the current time since the 
>> start of navigation. Let me know if I misunderstood your intention here.
>
>Right, I'd just like it to be called out explicitly.

I have added a note that clarifies this behavior.

Thanks,
Jatinder
Received on Wednesday, 11 April 2012 16:19:02 GMT

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