Re: [Chicken-users] RE: srfi-19 time, flonums and s11n

[John Cowan]

Shawn Rutledge scripsit:

> http://en.wikipedia.org/wiki/Unix_time says Posix defines the
> timestamp as seconds since 1970 without taking leap seconds into
> account.  So Posix time is identical to monotonic time as defined in
> SRFI-19, right?

In some abstract sense, yes.  However, actual implementations of
Posix time are subject to backward leaps to repair clock drift and
other difficulties, and cannot be used as sources of monotonic time.
Typical examples of monotonic time are "hardware clock ticks since last
reboot" or "since this Scheme image was launched" or whatever -- there is
no requirement that monotonic time be referrable to external time sources.

Posix.1b (aka real-time) compliant systems, including Linux and Solaris,
can create monotonic timers with timer_create(CLOCK_MONOTONIC, ...) calls.

-- 
Barry gules and argent of seven and six,        John Cowan
on a canton azure fifty molets of the second.   address@hidden
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