[sane-devel] Has anyone managed to get Snapscan backend working with FreeBSD 8.0 (which uses libusb)?

[Oliver Schwartz]

Hi all,

On 26.01.2010, at 15:46, m. allan noah wrote:

> Seems like an individual backend should not need to parse the device
> string. Isn't there some other way to come up with a unique semaphore,
> like process id?


the process id could be used, but it may fail theoretically. One  
example is a frontend that uses two (snapscan-)scanners at the same  
time (not that I think anybody actually does that).

The clean solution is a semaphore per device. In the days before  
libusb the backend used ftok(). The current code was written by  
Julien, as far as I know, because the ftok() call failed miserably and  
the unique id was always 0.

So I guess I'll stay with the device string, but maybe use some sort  
of crc instead of parsing it. Other ideas are, of course, welcome.

Kind regards,

Oliver