[ENet-discuss] Enet's Timer Precision Needs (timeBeginPeriod)

[Sven Bergström]

MIKE, what are you doing on my list!

So, I think it's also implementation detail of the game itself, much like
ruud suggests.
Some games would not need lower precision, some games would.

Though that doesn't mean I understand the full extent of the changes on
ENet internals,
it doesn't appear to (by digging around in the code) change enough to cause
problems.

I'd wait for lee to weigh in, though.

Sven

On Sun, Oct 21, 2012 at 7:49 PM, Ruud van Gaal <ruud at racer.nl> wrote:

> I would say the time accuracy has an influence on ping time, where it
> helps to get millsecond accuracy instead of just 15ms.
> Resend times are big enough to probably not be influenced much.
>
> Still, any game quickly uses 1ms timing, if only for accurate fps timing.
>
> I think ENet will run, but just a bit more jerky than is needed.
>
> Ruud
>
>
> On Sun, Oct 21, 2012 at 6:06 PM, Mike Kasprzak <mike at sykhronics.com>wrote:
>
>> Hi,
>>
>> I have a bit of an overly technical enet implementation question, so
>> apologies in advance.
>>
>> Long story short, I've been going through and doing some work to make
>> an older game of mine pass Intel's power use certification tests. To
>> do that, you run Intel's Power Checker tool alongside your app/game:
>>
>>
>> http://software.intel.com/en-us/software-assessment?&paneltab[tabs-28-main]=pid-252-28#pid-252-28
>>
>> The older game is totally single player game that doesn't use
>> networking at all. That said, I was investigating one of my fail
>> points (timer precision) by running my new games client and server,
>> where I noticed even the server (without any graphics at all) was also
>> using a 1ms precision. A bunch of digging later, I found a
>> "timeBeginPeriod (1);" call inside win32 implementation of
>> enet_initialize.
>>
>> My question is: How important is timer precision to enet's overall
>> implementation?
>>
>> I realize that's a vague question, so let me clarify. Raising (or not
>> changing) the timer precision means calls to timeGetTime() will simply
>> not return new numbers until the timer period has passed. So, if the
>> Windows default of 15ms is used, no matter how many times you call it
>> during those 15ms, it will not change. For reference, timeGetTime is
>> used inside enet_time_get and enet_time_set, so that's how it affects
>> enet.
>>
>> So a better question: What would a lower precision timer break in enet?
>>
>> Like, is the time used in any way that may delay packets? Or is it
>> purely statistical, like it will just ruin our frame of reference on
>> when a packet was sent/received?
>>
>> Thanks,
>>
>> Mike Kasprzak
>> Sykhronics Entertainment
>> www.sykhronics.com
>> _______________________________________________
>> ENet-discuss mailing list
>> ENet-discuss at cubik.org
>> http://lists.cubik.org/mailman/listinfo/enet-discuss
>>
>
>
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