cons: Support epolling /dev/null
authorBarret Rhoden <brho@cs.berkeley.edu>
Mon, 20 Mar 2017 22:37:31 +0000 (18:37 -0400)
committerBarret Rhoden <brho@cs.berkeley.edu>
Tue, 21 Mar 2017 18:29:06 +0000 (14:29 -0400)
commita98db982ca25451f59465925a9bc6dc1adf6ed26
tree8f78cc11b06c09dbcee142e0885c7d0cca588a6e
parentd88263dc86a37918cc86b014353a3cf4c6c8e3c2
cons: Support epolling /dev/null

Some apps want to epoll on their output streams.  If that's redirected to
/dev/null (#cons/null), then they will try to epoll/select/poll on it.

We don't have actual edges, but we can fake it.  And we'll also need to
support stat reporting writable.

Signed-off-by: Barret Rhoden <brho@cs.berkeley.edu>
kern/drivers/dev/cons.c