Re: [MIT-Scheme-devel] feature request

[naruto canada]

On 9/16/08, Taylor R Campbell <address@hidden> wrote:
>    Date: Tue, 16 Sep 2008 18:45:12 +0000
>    From: "naruto canada" <address@hidden>
>
>    On 9/16/08, naruto canada <address@hidden> wrote:
>    > On 9/16/08, naruto canada <address@hidden> wrote:
>    >> On 9/16/08, Taylor R Campbell <address@hidden> wrote:
>    >>> What does %N mean?  It's not a standard strftime(3) format.
>    >
>    > It means nansecond.
>
>    typo, nanoseconds.
>
> Thanks.  There is currently support in MIT Scheme for nanosecond-
> resolution clocks; the best you get is microsecond resolution from
> gettimeofday(2) with the nullary REAL-TIME-CLOCK procedure, although
> it yields a number relative to the start of the process.  Adjusting
> this to get a number of microseconds relative to some epoch is a
> simple matter of programming, but since you wanted to combine it with
> the number of seconds since the epoch anyway, this doesn't matter
> much.
>

with a 2G cpu and the threading speed of linux I would still worry
about two processes getting the same number with microsecond
resolution. It's unlikely but still possible, that only 2000 clock
could have switch two processes on a linux machine.