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Re: Need clarification for cyg_mbox_timed_get()
- From: Nick Garnett <nickg at ecoscentric dot com>
- To: Jay Foster <jay dot foster at systech dot com>
- Cc: "'ecos-discuss at sources dot redhat dot com'" <ecos-discuss at sources dot redhat dot com>
- Date: 17 Jun 2004 19:25:32 +0100
- Subject: Re: [ECOS] Need clarification for cyg_mbox_timed_get()
- References: <80B97DE95AEED311BA580050047FE98494FA74@mail.systech.com>
Jay Foster <jay.foster@systech.com> writes:
> The documentation for cyg_mbox_timed_get() states that it "will wait until
> either a message is available or until a number of clock ticks have
> occurred."
>
> Occurred since when?
>
> I assumed it was clock ticks occurred since the call to
> cyg_mbox_timed_get(), but it seems to behave as if it is clock ticks
> occurred since boot time (not as useful). What is the correct behavior?
>
As with most timeouts in eCos, the timeouts for message boxes are
absolute times rather than interval times. This is because it is easy
to synthesize an interval timeout from a API that uses an absolute
time, but it is not possible to synthesize an absolute timeout from an
API that takes an interval time.
--
Nick Garnett eCos Kernel Architect
http://www.ecoscentric.com/ The eCos and RedBoot experts
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