This is the mail archive of the ecos-discuss@sources.redhat.com mailing list for the eCos project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: cyg_semaphore_post


Robin Farine wrote:

> On Mon, 2002-02-11 at 13:38, Stijn Symons wrote:
>
> [snip]
>
> > I'm mapping an API to eCos, the API states that  "When any threads are
> > waiting on the semaphore count to become higher than zero, the thread with
> > the highest priority will be woken up to acquire the semaphore".
>
> ... which in cases of heavy load of the semaphore will lead to
> starvation of low priority threads :-\

Then don't do that. ;>

If eCos were a `hard' real-time OS, it probably would behave the way that Stijn

describes, and if starvation resulted that would be down to programming error.
The `hard' real-timers would care only that the starvation was predictable. ;>

Of course eCos isn't `hard' real-time, so eCos semaphores will not deliver the
behaviour described in Stijn's API.

Chris Gray
VM Architect, ACUNIA



Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]