[9front] Thoughts on Wayland?

[Willow Liquorice <willow@howhill.com>]

Hello again 9front,

(Warning: long email is long)

I've been leafing through the Wayland protocol, comparing it to rio and 
/dev/draw. To me, a system that could speak Wayland sounds much more 
compatible with the wider software ecosystem.

Has there been much thought put into Wayland in 9front? I'd poke around 
in the list archives, but I haven't figured out how to 9P on my Linux 
machine yet.

Here are my thoughts:

1. The Wayland compositor and clients talk to each other over a Unix 
domain socket. I'm guessing Plan 9 doesn't have those (and doesn't want 
them) as there's nothing in sys/man on the subject. Could pipe(3) do the 
trick?

2. Shared memory (where wl_buffers are stored) is achieved by passing a 
file descriptor from the client to the compositor, which the compositor 
mmaps as needed.

If I understand correctly, that already sounds pretty plan9-y, though 
I'm not sure whether you could then treat the file *like* shared memory 
under 9front. Again, couldn't find any references to "mmap" in the 
manuals, so I guess there's no direct analogue. Could you achieve the 
same (or similar) effect with a ramfs?

3. protocol/wayland.xml is apparently used to generate all of the 
function prototypes you need to speak Wayland. If the underlying 
components (shared memory and a domain socket lookalike) work, making a 
Wayland library for Plan 9 (Way 9?) *might* boil down to a 
paint-by-numbers exercise.

Wayland's been around a while, so maybe none of these observations are 
new. I don't know! I'm a novice.

Regards,
	Willow