🚀 go-pugleaf

In article <1992Nov18.113155.165165@dstos3.dsto.gov.au> jav@dstos3.dsto.gov.au writes:

| I realise that the windows timer is only accurate to 18.2 ms, but
| surely the settimer function is able to correct for non-multiple of
| 18.2 ms intervals (obviously not!).  If not, then does any Guru out
| there know how I can correct the time to accurately be able to
| sample every sixty seconds?

Page 175 of Petzold, 2nd Edition:

        - The time interval you specify in the SetTimer call is always
	  rounded down to an integral multiple of clock ticks. For
	  instance, a 1000-msec interval divided by 54.925 msec is
	  18.207 clock ticks, which is rounded down to 18 clock ticks,
	  which is really a 989-msec interval.

Your other choice is to code your own message loop to delay until the
next interval is over. You can do a peek message and the usual
processing, including translate and dispatch and in between you can
check the time. When you reach your time, go for it.

Note that no matter what you do, Windows still does cooperative
multi-tasking, so that any one of your samples could be off by more
than a second if some other app held the CPU at the critical moment.
This would not affect the timer interval of course.
--
Kim Letkeman	kim@Software.Mitel.COM