Mir Developer: Anyone Interested In Native Wayland Clients In Mir?

[TheBlackCat]

I wouldn't draw the conclusion that Wayland has better architecture based on that statement, but rather it would be easier for developers to maintain only a single code path.

There are two paragraphs. The first talks about the Wayland architecture being better, the second talks about maintaining two code paths being difficult.

[TheBlackCat]

Well I assume it would be useful in the short term, allowing Wayland clients to run with Unity 8 (or rather one of the forks). AFAIK migrating Unity 8's code to Wayland is no easy task (likely requiring large reworking of code if I understand correctly).

Since Wayland is designed to make it easy to access the protocol in alternative ways, I would think it would much easier to create a Mir compatibility library on top of the existing Wayland protocol than it would be to completely redesign the fundamental Mir architecture from the ground up to make it much more like Wayland.

[ssokolow]

Gnome and KDE are able to run on both Xorg and Wayland, so maybe something similar would be doable with Unity aswell. It depends on how much Canonical cared about such aspect, I guess they went all in and have integrated Unity with Mir without any effort to limit Mir dependencies to certain components only.

Canonical wrote Mir patches for some KDE componentry (KWin, I think) and submitted them. The KDE devs said that, as a matter of policy, they don't accept patches into upstream that are used by only one desktop on one distro. (ie. "Come back once you've got someone else to also use Mir so it's not just 'please maintain part of our proprietary platform for us'.")

[Mystro256]

Since Wayland is designed to make it easy to access the protocol in alternative ways, I would think it would much easier to create a Mir compatibility library on top of the existing Wayland protocol than it would be to completely redesign the fundamental Mir architecture from the ground up to make it much more like Wayland.

Well I've personally never touched Mir's code, but I would assume if Alan, a Mir developer, thinks it could be advantageous, it maybe worth it, at least in the short term before porting Unity to Wayland, which the forks have mentioned is their goal. I'm not a Mir nor Wayland nor X developer, so I can't answer these questions, but from what I've read, separating Unity from Mir is not going to be an easy task; so from a high level, I assume there would be short term benefits.

I doubt it would be as simple as popping Unity on top of a Wayland compositor with Mir compatibility, if that's what you're driving at.

[Steffo]

Canonical wrote Mir patches for some KDE componentry (KWin, I think) and submitted them. The KDE devs said that, as a matter of policy, they don't accept patches into upstream that are used by only one desktop on one distro. (ie. "Come back once you've got someone else to also use Mir so it's not just 'please maintain part of our proprietary platform for us'.")

They never wrote a patch for KWIN. The maintainer (Martin Grässlin) wrote only, that he wouldn't accept patches for Mir.

[TumultuousUnicorn]

Please let's Mir and X die. Concentrate the effort into Wayland.

+1. Really, I don't understand why they still plan to develop Mir. Nobody will use it outside Ubuntu.
Having 3 display servers (or call it what you want) to support as same time is just a nonsense and a waste of time.

[DebianXFCE Jr]

+1. Really, I don't understand why they still plan to develop Mir. Nobody will use it outside Ubuntu.
Having 3 display servers (or call it what you want) to support as same time is just a nonsense and a waste of time.

X still has to be maintained before wayland proves to be production ready. But mir? For what purpose? Just because someone feels that all the effort putted into mir is going to trash? Naaaaah. Let mir die. And unity? Who will want to use it? Vanilla ubuntu users? There is a reason all the *buntus spins popped out, with even two KDE flavours. There is much work ahead unity devs to be done if they want to maintain it. I don't see the future for this de if there won't be any changes to some aspects of its interface.

[BwackNinja]

I'm actually starting to get concerned here. Has this really devolved into nothing more than a political discussion by people who have no idea what any of the terms involved mean?

We're talking about Mir literally becoming a Wayland compositor as well here. That is concentrating effort into Wayland, unless you think that having Mutter and KWin running as Wayland compositors is similarly a waste of effort.

The idea of "just port Unity 8 to Wayland" is a laughably absurd notion missing any understanding of where the shell fits within the stack. Wayland is still a protocol, not another display server for things to run on top of. This would mean making Unity 8 a Wayland-compatible compositor itself, giving it at least a DRM backend and the same support for Wayland clients that we're talking about in the first place. When we're talking about Wayland, the concept of a 'window manager' or a 'desktop shell' as separable concepts is at best an implementation detail of a specific compositor and not the only requirements of such.

Mir has a DRM backend as well as an X backend, it has the additional protocol to be able to handle a shell of it's own and the externalization of window management capabilities. Window management policies aren't restricted to floating windows, it also supports tiled, phone, and tablet styles of window management. You can do these things while writing drastically less code than is involved in writing a full Wayland compositor, and with this imagined native Wayland client support, you'd be a Wayland compositor anyway.

Frankly speaking, giving Mir support for Wayland clients would make MirAL arguably the best Wayland compositor library that exists, and one that's intended for more than the tiled use-case. The only compositor (beyond perhaps Weston itself) that I've seen uses libweston is WayHouse, as shown in an article less than a month ago. Correct me if I'm wrong, but I'm pretty sure this would be a good thing.

[Holograph]

Yeah let's make Mir into middleware

Let's make sure to keep using MirAL as middleware

Let's make even more layers of middleware. Yay middleware!


The real answer to the question is HELL NO.

[Malizor]

I'm not sure I understand. Would this actually turns Mir into a Wayland compositor?
If so, it would solve the main problem people have with it, so it's a good idea.

The protocol concern is a good point in favor of Wayland and I did not see it raised earlier.

About the Unity 8 forks, you have to understand that Mir cannot be simply "repealed and replaced". Using another compositor like Mutter or Kwin would basically mean a rewrite of the whole thing, and I guess there is not enough developers left now to do that in a reasonable time.
And if Canonical plans to keep maintaining Mir and can even be persuaded to turn it into a Wayland compositor, there is just no more relevant reason to ditch it.