Re: kqueue: SIGIO?

[David Holland <dholland-tech%netbsd.org@localhost>]

On Wed, Sep 30, 2015 at 11:28:35PM +0700, Robert Elz wrote:
 > It also fits with the only safe thing that's really possible to do in a
 > single handler being to set a variable and return (or exit the process)
 > (ie: the main loop has to check a variable anyway, whether signal delivery
 > is traditional, or via Mouse's suggested mechanism).
 > 
 > The issue with it is how one would ever safely clear the variable again,
 > while avoiding race conditions - 

An atomic read-modify-write cycle; other than vintage cpus have these
in hardware.

Anyhow, infiniband had to come up with some scheme for this; borrowing
that rather than reinventing it (or not borrowing it if it sucks,
instead of reinventing it by accident) seems like a good starting
point.

-- 
David A. Holland
dholland%netbsd.org@localhost