Subject: Re: selnotify: knhint?
To: None <tech-kern@NetBSD.org>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 01/30/2005 14:17:24
>> However, I am unable to find documentation which describes suitable
>> values for knhint [for selnotify].  [...]
> It's a flag passed to the device kevent filter.  Use whatever you
> want for it.

If I can use whatever I want, then what's the point of having it at
all?  I fail to see the point of even *having* an argument whose
semantics are "use whatever you please for this argument".  If it makes
a difference, then what is that difference?  If it makes no difference,
why have the argument at all?

> You probably want to always use selnotify(), unless your device never
> plans support for kevents.

Ah, that helps a little, in that it indicates not only *that* this is
tied in with kevents somehow (which I gathered from reading KNOTE(9))
but gives some idea of *how*.  In particular, it does mean that I'm
fine with using selwakeup() as long as userland doesn't care about my
code playing nice with the kqueue/kevent framework.

Perhaps all I need is a tutorial document on kevent/kqueue.  Does such
a thing exist?

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