[ECOS] POSIX and uITRON question.(system level and application level?)

Grant Edwards grante@visi.com
Thu Jan 16 17:40:00 GMT 2003

On Thu, Jan 16, 2003 at 06:30:35PM +0100, Gary D. Thomas wrote:

> > > Does it mean: POSIX is standard for operating System level and
> > > uITRON is standard for application(level) interface to OS ?
> > 
> > No.  
> > 
> > Both specify an API that applications use to access OS services
> > and functions.  They are alternate "wrappers" for the basic
> > eCos kernel API.
> > 
> > I don't know whether it's possible to configure/use a system
> > that has both Posix and uITRON packages.  In theory it should
> > be, but there may be implimentation practicalities that prevent
> > it.
> I seem to recall that we (the eCOs team) discussed this and decided
> that it would not work properly (uItron tasks are not very friendly
> with POSIX threads).  It also doesn't make much sense (at least not
> to me) - they are somewhat opposing ways of writing a realtime system.

The only situation I can see where it might be useful is if you
had several chunks of legacy code you wanted to combine in a
single system: perhaps a web server that uses a Posix API and
some machine control algorithms originally written for a uITRON

That's a purely artificial example and it sounds like a good
way to get yourself into a mess...

Grant Edwards

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