Re: Faking Uptime

FROM : Kaelin Colclasure
DATE : Wed Mar 19 23:09:15 2008

On Mar 19, 2008, at 2:26 PM, David Dunham wrote:
>
> On 19 Mar 2008, at 11:46, David Dunham wrote:
>

>>> Have you checked your code to make sure you're not converting an 
>>> uptime (TickCount, Microseconds, etc.) calculation into 
>>> milliseconds while using a signed 32-bit value?

>>
>> Well yes, I'm sure the bug is something like that. But I didn't 
>> spot anything obvious the last time I had a 25-day machine (which 
>> unfortunately got rebooted before I solved the bug). I'd like to be 
>> able to debug and see where the value gets flipped negative.

>
>
> It's not actually negative -- I think AbsoluteToDuration maxes out 
> after ~25 days. (It doesn't wrap, the way its Windows equivalent 
> does after 50.) I'm using AbsoluteToNanoseconds now.
>
> So now I'd still like a way to force UpTime() (it's in 
> DriverServices.h) to return a value of 50 days, to test my fix, and 
> have QA verify it.



I don't have time to try this out myself just now, but *in theory* a 
destructive dtrace script might be able to do this.

$ man dtrace

The best place to get a fast, definitive answer is probably: <email_removed>

-- Kaelin



>
>
> BTW, none of these functions are documented in Xcode. And I updated 
> Developer Documentation yesterday...
>
> David Dunham
> Voice/Fax: 206 783 7404            http://www.pensee.com/dunham/
> Imagination is more important than knowledge. -- Albert Einstein
>
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