qio: Fire read taps on actual edges
authorBarret Rhoden <brho@cs.berkeley.edu>
Tue, 22 Mar 2016 14:02:05 +0000 (10:02 -0400)
committerBarret Rhoden <brho@cs.berkeley.edu>
Tue, 22 Mar 2016 14:02:05 +0000 (10:02 -0400)
commitdbaaf4a3029ec172a78069f44dc2c7fb8986985b
tree82368f4e8de4d8217dbd28ca62a8de98780fc52d
parent0fdf3590bdc1bcac962c9397eaf079804a4d7842
qio: Fire read taps on actual edges

We were only firing when the queue was Qstarved, which means that someone
had to attempt to drain the queue at some point.  Thus if the queue was
drained exactly, but no one waited, then the tap wouldn't fire.

Now we fire whenever the queue was empty, not when it thought it had a
someone who starved it.

Signed-off-by: Barret Rhoden <brho@cs.berkeley.edu>
kern/src/ns/qio.c