Re: [ECOS] semaphore bug??

[Jonathan Larmour <jlarmour@redhat.com>]

Andrew Lunn wrote:
> 
> On Wed, Aug 15, 2001 at 11:49:32AM +1000, Geoff Patch wrote:
> >
> > Hi Folks,
> >
> > > I don't think you can post to a semaphore from an ISR.  You'll
> > > have to run a DSR and do it there.  There's a table in the eCos
> > > Reference Manual (Device Driver Interface to the Kernel) that
> > > shows what functions may be called from an ISR.  About the only
> > > thing you can do is ack/mask/unmask interrupts and run a DSR.
> >
> > This is correct, and I recall other postings to the list about this issue.
> >  It's obviously a fairly common misconception.
> 
> How about adding an assertion check to semaphores and mutex etc. If
> they are called from within an ISR throw an assertion.

Unfortunately there is no portable way to determine if you are in an ISR.
Instead you would have to set a HAL level boolean in the interrupt VSR
before calling the ISR. And if the ISR, for whatever reason, doesn't exit
by returning, it would all go very wrong.

Jifl
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