Re: AW: [ECOS] Blocking restricted in DSRs

[Nick Garnett <nickg at ecoscentric dot com>]

"Neundorf, Alexander" <Alexander.Neundorf@jenoptik.com> writes:

>  
> > Things like waiting for a semaphore. Blocking is something you do at
> > thread level. The thread "blocks" (or goes to sleep) until another
> > thread or interrupt wakes it up again. Basically, this waking 
> > up is done
> > by the scheduler, which explains why you should not block in a DSR,
> > which is called _before_ the scheduler. 
> > 
> > Hope this makes it a little bit clearer,
> > 
> > Bob
> 
> Ok, the docu says sending signals to condition variables is ok from
> a DSR. But AFAIK this has always be done together with locking the
> associated mutex first... from the DSR then. But the docu also says
> using cyg_mutex_lock() should be used only from thread context, not
> from DSR. So, what's the right way then ?

It also says that cyg_mutex_signal() can be called without locking the
associated mutex first. This is how it must be used from the DSR.


-- 
Nick Garnett                    eCos Kernel Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts


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