[racket] FFI question: 0 microseconds returned from gettimeofday call

On Fri, Jul 15, 2011 at 8:40 PM, Jon Zeppieri <zeppieri at gmail.com> wrote:
>
> I *think* it's fairly
> safe; it should always err on the side of passing in too large a chunk
> of memory, so it shouldn't start stomping on random addresses.

Just to be clear: the code isn't safe if the tolerances are too
narrow. The code I wrote assumes that the calls to (current-seconds)
and (gettimeofday) occur on the same second when determining the size
of time_t, and that the calls to (current-inexact-milliseconds) and
(gettimeofday) occur within 100 microseconds when determining the size
of suseconds_t. Of course, you can't guarantee this.