friday, 1 february 2008

posted at 22:28
tags:

As you know, I've been at linux.conf.au this week. There's a lot of cool stuff happening in the Linux world, and a few of those things really made me ache to grab the code and get hacking on them. But even more than the technology, the best thing about Linux is the community. Even when there's disagreement (and there's plenty) the feeling is wonderful because everyone is working hard on the same thing: making computers awesome.

A shortlist of things I'd like to work on:

  • Martin Krafft's netconf network configuration framework. His design is elegant and this is something that Linux badly needs.
  • Rusty Russell's lguest hypervisor which is just beautiful in its simplicity. I've already done some real hacking on this in the tutorial and its very pleasant to work on. I had a chat with Rusty about adding support for gdb stubs (because I like that kind of thing) and it looks like it could be added quite easily. That sort of gratification is hard to come by. Plus I'm feeling happy because I won the prize in the tutorial for the most progress made (four targets reached in two hours). Its some kind of Brazilian liquor called Chico Mineiro that I'm looking forward to trying at the next gaming night.
  • cairo is still outstanding and from its requirements have come some major redesigns of the 2D graphics core in X and below. By the time the wizards are done with it cairo (and others) will be able to get better performance out of 2D graphics hardware than any other platform (Windows included). This stuff is harder to get into but is by no means impossible.
  • The GNOME crew have got some fascinating stuff coming down the pipe that I'd really enjoy working on. Its mostly integrating different types of application to better support social interactions (ie convenient sharing your stuff), which is something I've always had an interest in.
  • I've been gifted an OLPC XO-1. In the immediate future I've decided to let Francesca at it and document her progress, as a kind of observation project. The thing about these machines is that the are purpose-built for sharing and working with others, and the interface breaks all the rules and thus gives heaps of scope for trying new things. Whether she gets sick of it and hands it back or I buy one for myself so that we can play with them together, there's lots I'd like to do with it.

So there, lots of stuff I could do that I'd thoroughly enjoy, that would produce real stuff that would be used on real computers by lots of real people, and that would keep this community buzz alive for me.

On the other side, there's AROS. Now I like AROS because its technically interesting and there's lots of stuff to fix, but previously I didn't really have anything better to do. I still like AROS, but I've found myself this week doing a lot of soul-searching, trying to decide if AROS hacking is really the best use of my time. As I look at what's happening this at LCA this week, its increasingly apparent that AROS, when held up against just about everything else, is insignificant.

I don't have any delusions about AROS ever becoming a mainstream system, and thats fine, because it doesn't need to be to still be considered successful. In order to be successful, it needs a clear plan and goal moving forward (so we can actually measure our progress), and it needs a strong community of developers around it committed to that goal.

As it stands, we have none of that. The community, such that it is, is fractured, which is unsurprising since its a part of the Amiga community and we all know just how much infighting there is and has always been there. In terms of goals, there basically are none. There are those that would argue that "AmigaOS 3.1 compatibility" is the goal, which I'd answer by either saying we're already there since most source from the 3.1 era will compile and work with no or only minor tweaks, or that the goal is irrelevant since there's nothing from the 3.1 era you'd want anyway.

If we are to be a clone, then we're still a long way away - AROS can't even run on real Amiga computers! We're incompatible in a number of ways, but those ways are only important for binary compatibility, which we don't have. On the other hand, if you have the source, perfect compatibility is not really an issue as you can modify the application for the differences. But like I said above, there's nothing from the old days thats worth bothering with.

In the absence of real goals, I set my own personal goal for my work on AROS, which is to get it to a point where I could run it as the primary OS I use day-to-day on my laptop. That's a huge task, as my laptop is something close to an extension of my brain. AROS would need to at least be able to do the following to supplant Linux there:

  • Web browser
  • SSH client
  • Fully xterm-compliant console
  • Stable and fast filesystem
  • X server (for remote applications)
  • Perl
  • Proper support for my laptop - wireless, idling, suspend, etc
  • Some way to run certain Windows apps (like VMWare, qemu, etc)

It should be clear that there's more to it than just this list - a massive amount of work needs to happen under the hood to support all this.

As you can see, my aims are very forward looking, and make no provision for backward compatibility. This is causing some problems as I try to progress things. An example is my recent work on cairo. AROS graphics APIs are broken in the way the handle certain things related to alpha channels. Unfortunately this can't be changed without breaking backward compatibility. As such, I've implement a particular fix in four different ways over the last two weeks. The first three have introduce compatibility issues and I've had to remove them. I'm hopeful that the current one will not introduce any further issues, but I hoped that last time. Even if it does stick, I still needed a pretty nasty and performance-degrading hack in cairo to finally get what I wanted.

Obviously, this is frustrating. Perhaps it wouldn't be so bad if everyone was at least trying to move forward, just breaking as little as possible in the process (something I agree with), but there is an entire camp that appears to want backward compatibility at the expense of all else.

If I haven't been clear yet, I don't think that this is a bad goal. I have no issue with people wanting things that are different to what I want. The problem that I have in this case is that I don't see that the two positions can ever be reconciled as they're fundamentally opposed.

So I'm frustrated anyway, and then I go to a conference and hear and see amazing things by focused and motivated hackers, and I get even more frustrated because I want what they have. I want to work with these people on code that matters with the confidence that we're all moving in the same direction. This is why I'm starting to wonder if AROS is such a great place for me to be.

I've had some discussions in #aros about this, and the idea of forking the project often comes up. I've considered this in the past, but I've so far resisted for a few reasons. From the practical side its a pain because I'd have to setup the website, repository, etc and do admin stuff, write a lot of email, write a plan and other project governance stuff. Socially it always sucks to split a community. I'm starting to think that if I want AROS to move forward, I may not have much option.

The important thing that would have to happen before a fork is to very clearly determine what I want not-AROS to be. I think "modern" and "Amiga-like", or perhaps "Amiga-inspired" are probably the simplest ways to describe where I think things should go, but we have to specifically define those terms. "Modern" is pretty straightforward: the goal should be that if I put not-AROS on my computer, it will make efficient and effective use of my multiple processors, my piles of RAM, my wireless controller, my USB devices, etc. I should be able to use my computer to do any task that I can do currently in Linux or Windows. That of course requires a lot of applications to be written, but there should be nothing inherent in the system that prohibits those applications being made.

"Amiga-inspired" is a little more difficult to define. I've asked a few of the AROS crowd, and nobody seems to really be able to quantify it, which I find surprising since they're usually the advocates for it and came from Amiga in the old days. Perhaps its one of those cases where its difficult to define what you know because its been obvious for so long.

I don't have an Amiga heritage, coming from Unix as I have, so perhaps I can do better. Since I have no issue with changing the internals, we should start by looking at the Amiga from a user perspective. The major thing is that the system is designed to be GUI-driven, and as such the primary interface is a light and functional GUI. Unix of course is the other way around, where the command line reigns supreme.

The next major thing is the fast booting time. An Amiga system was typically ready for use within seconds of starting. Interestingly, if you measure the boot time as being from the time when the bootloader first hands control to the system to the time when the primary interface can be used, Linux actually only takes a few seconds too. The standard Unix boot sequence generally readies all system services before giving control to the user, whereas the Amiga was more likely to load things it needed on-demand. This made sense given the small amounts of memory available to the system, but that does not mean that its not a good model even for a modern system (though more options exist given the available resources, like starting services in anticipation of their use).

Much of this is enabled by the extremely light microkernel architecture. There's so little structure that system processes actually run much closer to the metal than they wood on other systems. I'm not sure how sustainable this would be as more features and system services are added, but neither have I had much chance to think about in detail. I see no particular reason why it couldn't be kept light if it was always being considered at every stage of development.

So to summarise, not-AROS would:

  • Boot fast
  • Assume a GUI (but see below)
  • Not keep stuff around that isn't needed
  • Keep the microkernel vibe
  • Let you do what you want without getting in your way

A word about the GUI. I'm a command line junkie. I type fast but am really uncoordinated when it comes to using the mouse. So my personal requirement (and I get to have them if its my project) is that everything you can do in the GUI you can do via the command line, and vice-versa. That requirement is fairly straightforward to achieve by seperating function from form - guts in a library, with UI of any type that calls it. Remotely controlling GUI applications is also something that Amiga has a history of with AREXX ports and the like.

And so then we get to backward compatibility. The fact is, I don't care. My not-AROS would not be an Amiga clone. It would try to follow roughly those points above but would be happy to break the rules when they don't work. It would aggressively steal from other systems past and current, both in ideas and in code. Additionally, once implemented, I would not be afraid to gut the internals and redo it if it became clear that we did it wrong the first time.

So there's high-level goals. They're deliberately nonspecific, which is what you want at that level. For the actual development cycle, I'd probably aim for regular releases (depending on available developers) each focusing on one or two specific areas. There'd be no nightly builds. You either get the source and build it yourself, or you wait for a release. I have ideas already about what I'd work on and change and in what order, but I'm not going to write about that here because the tasks are actually somewhat irrelevant.

From where I sit right now, AROS is in an untenable position. In my opinion it cannot get to where I think it could by continuing to be managed the way it is.

What will I do? For now, I'm committed (and still enjoying) my work on WebKit and cairo. I will complete the Traveller bounty. At that time, I'll consider my options, which will be three:

  • Abandon AROS development altogether and go and work on Linux stuff, and enjoy myself, but always wonder what might have been.
  • Continue work on AROS and likely continue beating my head against the wall until I finally explode.
  • Fork AROS and see what happens with the high likelihood that it will go nowhere and wast a lot of my time, with the guarantee that a good amount of my time will be sent managing the project rather than writing code.

What would be great would be if the AROS crowd managed to make a hard decision one way or the other before I have to decide properly. It won't happen, but it still would be very nice.

So thats it. Thats about the sum total of my thinking this week. If you're going to add a comment, please make a good argument for or against what I've said. This is actually a serious post, and I'm not interested in hearing from the fanboys this time around. If you post "I agree!" or "don't ruin AROS for everyone!", expect to have your comment deleted. And if you are going to disagree, make sure your have a pretty solid argument to back up your position because you'll be wasting your time if you don't - I've agonised over this stuff this week and I'm quite sure of my own position.