On Wed, Mar 23, 2016 at 05:50:19PM -0700, Eliot Miranda wrote:
> On Wed, Mar 23, 2016 at 4:51 PM, David T. Lewis <lewis at mail.msen.com> wrote:
> 
> > On Wed, Mar 23, 2016 at 04:22:21PM -0700, Eliot Miranda wrote:
> > >
> > > Turns out this isn't needed for Cog.  I have ioLocalSecondsOffset which
> > > answers a value determined at start-up and only changed
> > > via ioUpdateVMTimezone, which itself is controlled by
> > > primitiveUpdateTimezone, #243.  So ioUTCMicroseconds is all that's needed
> > > to get at the clock and timezone atomically.
> >
> > If it is updated at start-up, then it's wrong. Think of daylight savings
> > time transitions.
> >
> 
> So update it automatically once a second or some such?
> 

Are you joking, or is that a serious question?

Confused,
Dave


/* implementation of ioUtcWithOffset(), defined in config.h to
/* override default definition in src/vm/interp.h
 */
sqInt sqUnixUtcWithOffset(sqLong *microSeconds, int *offset)
{
  struct timeval timeval;
  if (gettimeofday(&timeval, NULL) == -1) return -1;
  time_t seconds= timeval.tv_sec;
  suseconds_t usec= timeval.tv_usec;
  *microSeconds= seconds * 1000000 + usec;
#if defined(HAVE_TM_GMTOFF)
  *offset= localtime(&seconds)->tm_gmtoff;
#else
  {
    struct tm *local= localtime(&seconds);
    struct tm *gmt= gmtime(&seconds);
    int d= local->tm_yday - gmt->tm_yday;
    int h= ((d < -1 ? 24 : 1 < d ? -24 : d * 24) + local->tm_hour - gmt->tm_hour);
    int m= h * 60 + local->tm_min - gmt->tm_min;
    *offset= m * 60;
  }
#endif
  return 0;
}