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From: Anthony Williams (anthony_w.geo_at_[hidden])
Date: 2007-11-28 06:59:12

"Peter Dimov" <pdimov_at_[hidden]> writes:

> Anthony Williams:
>>> We should probably think of a way to enable the use of a monotonic clock
>>> with the absolute timeout overloads. It doesn't feel right to make the
>>> relative overloads the only way to access the functionality.
>> Yes, we should. However, absolute time is always going to have issues with
>> clock changes --- if I schedule for something now (2007-11-27 18:23:15 UTC
>> by
>> the current clock) to run tomorrow (2007-11-28 18:23:15 UTC), does it
>> schedule
>> for 24-hours from now, or for when-the-clock-reads the right time?
> These are UTC times. The monotonic clock (CLOCK_MONOTONIC) is not
> user-settable and for it, now+K always occurs after K seconds. For
> CLOCK_REALTIME, it schedules for the given time.

OK, so we have three overloads:


The question is: how do we implement a monotonic clock? CLOCK_MONOTONIC is
optional on POSIX, and GetTickCount wraps on Windows.

On Windows, we could use the System Up Time performance Counter, but I'm not
sure what the resolution is.


Anthony Williams
Just Software Solutions Ltd -
Registered in England, Company Number 5478976.
Registered Office: 15 Carrallack Mews, St Just, Cornwall, TR19 7UL

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