Most Efficient Timer?

[Richard Gaskin]

Dave Cragg wrote:
> 
> On 29 Nov 2004, at 09:11, Richard Gaskin wrote:
> 
>> Scott Rossi wrote:
> 
> 
>>> Both of the above routines provide the same output.  However, when 
>>> viewing
>>> the %CPU use on a Mac OSX system with the Activity Monitor, CPU usage is
>>> clearly dependent on the frequency of the "send in" message: with 100
>>> milliseconds frequency, the first handler runs at about 15% usage, 
>>> and with
>>> 50 milliseconds frequency runs at about 30% usage (makes sense).
>>> Amazingly, the "wait x with messages" handler runs at less than 1% 
>>> usage.
>>> And because "with messages" does not block other messages from being 
>>> sent,
>>> this seems a very efficient way to run a timer.
>>> Obviously the above is useful only in situations requiring accuracy of 1
>>> second or less, but at first glance I can't see any drawback to using 
>>> this
>>> method.  Can you?
>>
>>
>> None that I can see, but I managed to get myself confused on the 
>> issue:  if you only want a time sent once a second, why not just send 
>> it in 1 second rather than polling several times a second?
>>
> I guess Scott was concerned about the smoothness of the time display 
> ticking over. If you send every 1 second, and there is something holding 
> up message processing, the timer may be late to update. Increasing the 
> frequency increases the chance of getting it right (but doesn't 
> guarantee it).

Wouldn't any issues that would delay the firing of a one-second timer 
also delay a 1/10th second timer as well?

--
  Richard Gaskin
  Fourth World Media Corporation
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