Priority inversion and CSP channels?

[Oyvind Teig <Oyvind.Teig@xxxxxxxxxxxx>]

Guys

We had a round about this the other day. I'll add this:

In last number of Dedicated Systems Magazine, they
say about QNX (http://www.dedicated-systems.com/): 

"QNX 4.25 
  .. is completely message based..
  .. does not provide mutexes. Priority-inversion safe mutexes
     can be simulated by means of threads and message passing
     services, but at the expense of performance and flexibility.
     Mutex objects should be provided."

My comment:
  The last sentence is on Martin Timmermann's own account.
  He hasn't deeply understood what message passing is about.
  You don't "simulate", you design correctly and use a
  pattern to avoid priority inversion altogether (like Peter
  described)! 

-- 
Oyvind
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