Michael Scheibel m.scheibel at sirrix.com
Mon Jul 24 12:52:46 CEST 2006

Am Sonntag 23 Juli 2006 11:02 schrieb Ronald Aigner:
> Hello Michael,
> Michael Scheibel wrote on 21.07.2006 17:20 this:
> > Running the generated stubs we noticed that ~0.89% of the IPC
> > transactions fail. In such a case the parameters passed to the server
> > still contain their initialization values on return. The client trace
> > says "ipc error c0" and the server trace says "DICE_NO_REPLY".
> IPC error code 0xc0 is "IPC: Receive operation aborted". This usually
> only occurs if the thread's state is changed (using the l4_exregs system
> call). My first guess is that either server or client are L4Linux
> applications and L4Linux is changing the thread state. That would
> axplain the "ipc error c0". Because the IPC is aborted, the parameters
> are not overwritten and thus still contain their initial values.

You're perfectly right, both client and server are L4Linux applications. 
However, I still don't understand what the l4_exregs syscall does and how it 
affects the state of the server and/or client thread. Second, I wonder if 
there is an option to avoid the resulting IPC aborts. The only solution I can 
think of are manual retransmissions in case of a failure (which is not really 
a solution but rather a work-around).


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Michael Scheibel  eMail: m.scheibel at sirrix.com
Tel +49(234) 610 071-124
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