[sane-devel] SANE2 standard revisited: sane_get_select_fd

[Matto Marjanovic]

 >> > So, why bother?  Remove sane_set_io_mode() and eliminate more confusion.
 >>
 >> No objection from me.
 >
 >We should not remove this. It does not cost anything to leave it but
 >it gives the frontend the chance to implement a quick user
 >interface.

I don't see any real benefit to leaving it in.

A slap-dash frontend could implement a responsive user interface using
 this technique, but only for backends which implement non-blocking I/O.
 Such a frontend cannot *guarantee* a responsive user interface.

A frontend which actually wants to guarantee a responsive user interface
 must implement its own mechanism to circumvent blocking backends.
 Once the frontend has this code, it no longer cares if there is support
 for non-blocking I/O or not.

-matt m.