[Possible SPAM] Re: Using msvcrt (in Windows), how to catch Enter key?

[Gabriel Genellina]

En Mon, 29 Oct 2007 21:22:36 -0300, Dick Moores <rdm at rcblue.com> escribió:

> At 03:23 PM 10/29/2007, Gabriel Genellina wrote:
>> En Mon, 29 Oct 2007 14:39:49 -0300, Dick Moores <rdm at rcblue.com>  
>> escribió:
>>
>>
>> At least add a small sleep() call inside the loop, to be nice to other
>> running processes:
>>
>
> Yes, that makes a major difference in the CPU
> usage percentage on my computer. In fact I can't
> even tell that there is anything going on other
> than the usual behind-the-scenes XP stuff. CPU
> usage stays right around 0% or 6%, with an
> occasional 6% and a very occasional 15%.
> Interestingly, sleep(0.001) makes as big a
> difference as your sleep(0.1), but sleep(0.0001) bumps it up to a steady  
> 100%!

The underlying function in Windows is Sleep (or SleepEx) which takes an  
argument in milliseconds. 0.0001s = 0.1ms and it's rounded to 0. Sleep(0)  
has very specific semantics - for a single threaded program, it does  
nothing, so your code is effectively a busy loop taking 100% CPU.

-- 
Gabriel Genellina