Compiz to be Rewritten for Ubuntu Wayland

by Susan Linton - Nov. 07, 2010Comments (12)

Compiz on WaylandA few days ago I theorized that Mark Shuttleworth's move to Unity on Wayland was an effort to focus his operating system more on mobile devices and, ultimately, cloud-based services. Unity's hardware compatibility is limited in range, at least for now, and Wayland is even moreso, again at least for now. But there's one part of the equation I failed to consider. What about the X11-dependent Compiz?

One of the more intriguing aspects of Wayland is that it does away with window managers. Instead it pushes all of the work of managing windows to the application. X11 and application developers have been resisting Ubuntu's push in that direction for a while. But with Wayland, it's built-in. This opens the door for one misbehaving application to bring down the whole graphical display - as seen in Windows.

Sam Spilsbury, the Compiz chief architect and developer, says Compiz will only have to be concerned with compositing in Wayland. In essence, all applications would become compositors. As Spilsbury says, "able to manage all of its own tabs, widgets etc all exposed as GEM buffers."

Wayland disadvantages aside, Spilsbury said one thing that will effect every distribution offering Compiz.

I am confident that with a lot of typing we can [in the same way that we split the opengl and composite plugins out of core] do the same with the remaining X11 bits in core - and split them out into an X11 plugin.


Since Spilsbury is now on Canonical's payroll, one has to wonder if X11 support will receive the same care and attention as in the past. His days are going to be quite full rewriting Compiz to work on Wayland as X11 simultaneously becomes the red-headed stepchild of the Linux world. Will users of Compiz on other distributions start to see diminished quality in their future?


Update: As an aside: Despite a flurry of activity over at the Wayland project, AaronP, NVIDIA developer, stated NVIDIA has no plans to support Wayland.

Abhijit Prabhudan uses OStatic to support Open Source, ask and answer questions and stay informed. What about you?


Really, making claims that now because I'm employed by Canonical that the X11 backend will receive no love or even that I want to "rewrite" compiz for wayland seems a bit far-fetched to me.

X11 is still a crucial part of how we work and I wouldn't expect support (or even regular development) for that to be dropped any time soon (and by soon I mean within the next 4 years). What I was merely trying to say in my blog post was "let's at least try the waters and see how they feel"

1 Votes

Also, I'm really not the "chief architect and developer of compiz", if there is such a thing. It just so happens that all of the other developers are busy with other things at the moment so I'm really just taking development for now while they're away. In fact, I have close contact with all of the original compiz creators and I always check with them before making large-ish changes.

1 Votes


1 Votes

Compiz to be Rewritten for Ubuntu Wayland

1 Votes

"This opens the door for one misbehaving application to bring down the whole graphical display - as seen in Windows."

Incorrect. One misbehaving application will not bring down wayland. GEM means each application has its own memory allocations and process allocations. So once this is defacto there is no reason why a Out Of Memory killer could not be implemented for GEM. So any rouge application can be cleaned up. Yes all applications GEM allocations under wayland are trackable to the application that allocated them. Not middle men like X11. Were if you cause a leak in the X11 server termination of the X11 server will cost you everything. wayland is avoiding this issue. Even what it is displaying avoids this issue.

Wayland is a more solid design.

When combind to KMS support wayland demards. Secure Attention Key(SAK) feature of the Linux kernel can now be used to perfectly terminate all graphical applications without disrupting background services. Even more impressive lets say you are running multi seat setup using 2 outputs on the same video card. Triggering a SAK event on 1 output would not effect the other. Were currently with X11 it can leave video card in a bad state.

Its not like its impossible to bring the graphical stack complete down with X11. It already happens. Handling methods up the other side are no where near as clean. With wayland we might at long last see a graphical process manager.

Each application being its own compositor means its able to be terminated with min effects.

1 Votes

"One of the more intriguing aspects of Wayland is that it does away with window managers"

according to a comment made on the discussions surrounding this issue, wayland does not do away with window managers:

"wayland does *not* require CSD. there will be a compositing+windowing manager (currently implemented as a plugin)."

greetings, eMBee.

1 Votes

You are forgetting one thing: Ubuntu 10.04 LTS will still be supported long after Wayland is incorporated into the new distribution...and LTS means "long term support"...which means that they will have one of three options with X11:

* Updated X11 support for 10.04 (and 10.10 until its support cycle ends)

* A Wayland replacement update for 10.04 (and 10.10) which is highly unlikely

* Enhanced 10.04 (and 10.10) application support for the final X11 kernel to be released

I think they'll go with the first option...

Oh, and by the way, Unity won't have less hardware support since that's built-in to the Linux kernel. Unity is just a UI shell.

0 Votes

Excited! This is a good step for Linux. had a similar friction when X11 was to be replaced.

0 Votes

One of the reasons I appreciate open source is the ability to mix things up and come out with something new. I remember the first time I saw openGL mixed with a window manager before it was out in the public and I loved it. Keep up the cool experiments and move all of us forward because of it.

Also, I think this may well be one of the first times I have read informative, mature, and clear comments to an article. Way to set the bar.

0 Votes

but if Unity is just a new shell... how come it can affect the number of hardware supported by the kernel?

i just don't get it.

0 Votes

Thanks for explanation, oiaohm. I remember very well how one app (one click?) crashed X and put down all I cared about on the desktop. The very same time the media was mad explaining how stable Linux is.

Currently the distros do not include XKill and even do not support Ctlr-Alt-Backspace, and I occasionally regret they do so.

Finally Linux gets a chance to live to its stability expectations on the desktop.

0 Votes

I think you should be doing "proper" research on a topic before you try to write an article on the subject.

Unity has nothing to do with hardware support. Much of what you say leads me to believe that in reality, you have no concept of how Compiz, Wayland, Unity or even how Linux works in general...

you must of just wrote this article to get hits.

0 Votes
Share Your Comments

If you are a member, to have your comment attributed to you. If you are not yet a member, Join OStatic and help the Open Source community by sharing your thoughts, answering user questions and providing reviews and alternatives for projects.

Promote Open Source Knowledge by sharing your thoughts, listing Alternatives and Answering Questions!