[python-win32] sleep() fine-control in Python - RDTSC, select() etc.

[Tim Roberts]

On Mon, 24 Jan 2005 16:32:35 -0800, Ray S <rays at blue-cove.com> wrote:

>void main()
>{
>   int ns= 1000000;
>   // make the sleep in 100th nanoseconds.
>   ns = (ns + 99)/100;
>   //ns -= FACTOR;
>
>   __asm {
>      rdtsc
>      // clock in EDX:EAX
>      // we ignore EDX since we asume ns is
>      // of shorter duration than that.
>  
>

This assumption is dangerous.  On a 4 GHz processor, the low-order 32 
bits of rdtsc wraps every second.

64-bit arithmetic is easy in x86 assembly.  You should get in the habit 
of using it with rdtsc.

-- 
- Tim Roberts, timr at probo.com
  Providenza & Boekelheide, Inc.