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

[Henning Meier-Geinitz]

Hi,

On Thu, Jul 14, 2005 at 03:46:09PM +0200, Richard Metzger wrote:
> If one of you thinks it's worth to persue this old-fashioned
> environment (I'm using Linux since quite some time and dislike
> Wintendo, but for several reasons it has to be Win98 in this case
> here) I'd appreciate any kind of insight into the backend's higher
> level structure and/or pointers where to stick my nose in :-))

I haven't really looked at the hp backend but quite some of the
backends use a reader process to acquire the data from the scanner.
That reader process is forked from the main process of teh backend and
tries to get data as fast as possible to avoid that the scanner starts
backtracking. That happens when the scanner's internal buffer gets
filled up. The reader process may use one or several buffers and may
ask the SCSI layer for several data buffers. Once one of this buffers
is filled, it's "sent" to the main process of the backend via a pipe
or shared memory. 

Bye,
  Henning