Bob Wilson bwilson@tensilica.com
Tue Oct 11 18:32:00 GMT 2005

Joel Sherrill wrote:

> Corinna Vinschen wrote:
> On Oct 6 13:19, Bob Wilson wrote:
> The XSI extension to POSIX requires that CLOCKS_PER_SEC be defined  
> to one million. The current value in newlib, except for RTEMS and  
> ARM, is 1000. Since this value seems pretty arbitrary, wouldn't it  
> be better to go with the POSIX value? Here is a patch to change it.
> 2005-10-06 Bob Wilson <bob.wilson@acm.org>
> * libc/include/time.h (CLOCKS_PER_SEC): Define to 1000000.
> Careful, please.  This could break newly compiled applications on
> systems using the CLOCKS_PER_SEC macro internally.
> I always thought this was an arbitrary and useless macro.  On RTEMS
> and many other systems, the clock tick quantum is configurable.
> Why is 1000000 suddenly right?

I'm afraid I can't answer the "why" question.  I stumbled upon this  
requirement a while back when I was trying to decide upon a less  
arbitrary value for this macro.

Judging from various mailing list archives, the change has been  
somewhat controversial, but it appears that several other prominent C  
libraries have adopted it.

The default value is easily overridden, so I'm not going to push very  
hard to get the default changed.  I thought it was at least worth  
calling to your attention.


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