Re: [PATCH v2] Input: evdev - Add EVIOC mechanism to extract the MTslot state

[Henrik Rydberg]

On Fri, Jan 06, 2012 at 07:55:44PM +0100, Henrik Rydberg wrote:
> > 2 different processes should be fine; the problem would be if 2 threads
> > of the same process share the same file descriptor. So far the rest of
> > evdev copes just fine with multiple threads using the same fd (all
> > operations are atomic in this regard), setting ABS_MT_SLOT before
> > fetching the state break this property.
> 
> Are we talking about the need for a per-client mutex, or something
> more subtle, like introducing indirect coupling between threads
> through per-client states? The former ought to be easily remedied.

Ok, maybe not to so easy after all, which probably answers my own
question. Looks like a EVIOCGMTSLOT, taking both slot and event code
as argument, would be the cleaner route to take. Another ioctl, how do we
feel about that?

Henrik
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