L4 IPC doubt

Rene Reusner rr13 at os.inf.tu-dresden.de
Mon May 2 17:42:01 CEST 2005

Tiago Jorge(tjpj at lasige.di.fc.ul.pt)@2005.05.02 16:13:53 +0000:
> Ronald Aigner wrote:
> >And the blocking szenario is:
> >- C1 calls S.
> >- S calls F, but blocks in the send phase of the call.
> >
> >Did I get it right now? (The respective code snippets or IDL would be 
> >helpful.)
> >
> >  
> >
> yep... thats the problem.
> if i use the emulated szenario explained above, the ipc between S<->F 
> works... if i put the client the S<->F does not work...:(
> my doubt remains... why can't i do the second IPC? because i've debugged 
> the client stubs and the server-side stubs and i've realized that S 
> blocks in the ipc_send, the call never arrives on the server...
Then i would say, F is simply not in open wait or in closed wait for S.
Maybe F is blocked, because it handles an another request.
If you use fiasco, i assume this, then simply check the state from F.
It should be in Thread_receiving|Thread_ipc_in_progress (the 
Thread_ready bit doesnt hurt to). 
The ipc partner should be * for open wait or S.


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