[sane-devel] Stuck somehow in porting to Win98/ASPI

Richard Metzger richardmetzger at web.de
Tue Aug 9 14:36:46 UTC 2005



Henning Meier-Geinitz <henning at meier-geinitz.de> schrieb am 16.07.05 22:09:14:
> Hi,
> On Fri, Jul 15, 2005 at 12:48:32PM +0200, Richard Metzger wrote:
> > Please, what is the design here? Shouldn't the child block the pipe,
> > so that the parent only returns from read(), when the child wants it
> > to?
> 
> Parent: create pipe, fork, close writing side of pipe, wait for data
>         from reading side of pipe
> Child:  close reading side of pipe, send data to writing side, when
>         finished close writing side
> Parent: when writing side is closed by child, close also reading side	
> 
> Bye,
>   Henning

Thanks a lot - that helped a lot to get closer to the problem, which seems to be that the parent's read returns (indicating EOF) before the child has issued it's first write.

I see, that  Peter Kirchgessner has implemented a mechanism to retry the read a certain amount of times when EOF is indicated - but only for the non-scsi case. I'll try to mimic this for the scsi part. 

Regards,
Richard.
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