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Realtime OS Jaluna
rkgmd writes "Jaluna-1, a software component suite based on the
respected chorus realtime os is now available in opensource (MPL-derived license) form. Jaluna, the company behind this, is a spin-off from sun to promote and develop chorus, and consists of many developers from the original chorus team before it was acquired by Sun. Chorus developed one of the earliest successful microkernel-based rtos's (could even run parallel, distributed unix in realtime on inkos transputers in 1992). Lots of good research papers here, and a link to the original newsgroup announcement."
I know it sounds harsh but the reality is that most courses worry about Java, C++, Jaluna and people become concerned about the technologies rather than the theories.
The person who knows Knuth will be able to code in any language, the person who doesn't is limited in what they can do. Did your course teach you how to dope a transistor, build an Op-Amp ? An AND Gate ? A Compiler for a processor you design ? An OS for that Processor ?
And did it do all of these by starting with theory or was the first lesson "Print hello world" ?
The problem with practical courses is that they teach people to be the bricklayers of the Software Engineering world. The theory course teach you to be the engineer and how to apply theory to practicality.
It isn't about being taught "cool" technologies, its about being taught the theory behind them. RTOS is great in that it teaches you about Thread-death, dead-lock, live-lock, IO blocking, race conditions in a very immediate environment, so when you build a bigger system you automatically avoid those issues because you understand what is the right way to work.
Some Universities do teach the cool theory stuff, but most people don't choose to do that as its harder. It also makes you less marketable in the first year after graduation as you don't have the buzzwords... 12 months on however you'll be roasting everyone.
An Eye for an Eye will make the whole world blind - Gandhi
College is to give you a foundation of understanding so no matter where the technology goes you will have the ability to learn it due to your broad base.
If you want tech training go to DeVry/University of Phoenix (what a crock name). This is why a degree is worth more than certifications.
Plus, no one is stopping you from learning about RTOSes. I'm going through the Minix Computer OS Design book by Tanenbaum right now. You can either be spoon fed like most university students, or you can get up off your ass, show some motivation and learn it on your own. This is why I never have a problem finding a job and others cant get an interview. People want to hire motivated workers not someone who'll just tow the line.
I left Uni with one programming language (Ada) (Okay and LISP, M68k, Prolog and other really useful languages!) one OS (AIX) but I understood however thing worked.
However the answer to the question "do you know X" is always "yes" the advantage to theory is that it makes the lie true. How long to learn a new language ? If you understand the theory then the only thing that matters is syntax, 2 days ? 3 more days to learn the libraries ?
You resume should say that at University you learnt the following, not "I taught myself" because employers will look for the former wording not the later.
Jesus though "Advanced web design" where you do Perl. What has the planet come to ? Sorry to sound like an old fart but "Advanced Web Design" doesn't sound like something in a degree, it sounds like a Dummies book. XML as a course ? Its a bloody markup language, what is there to learn ? XSLT ?!
Learning extra languages or technologies is simple if you just understand the principles. Then you can claim to have known them for years, even though it was only last week when you found out this interview required it. As long as you can understand the theory then everything else makes sense.... except VB.
An Eye for an Eye will make the whole world blind - Gandhi
VxWorks' and QNX's advantage over ChorusOS was a combination of wider BSP support and very mature toolchains. ChorusOS big advantage was that it was specifically targetted at distributed applications - this is a issue for applications that combine real-time performance with data-centre-like reliablility (particularly telco).
## W.Finlay McWalter ## http://www.mcwalter.org ##
Actually Windows 3.1 is closer to an RTOS than you think. In most RTOS's, a task can starve any other task running at the same priority (or lower). Same as the cooperative multitasking model in Windows 3.1.
I don't know what you are talking about. How could one starve another in a RTOS? Hard deadlines are set. Most of the time, the process with the closest deadline is selected (some have time estimates and do other optimizations). If a task doesn't complete by it's deadline, it can get preempted because completing the task was just not possible. In effect, you overloaded the system therefore it is unresponsive. AFAIK, any system that is that overloaded will be unresponsive and concentrate on the higher priority tasks. You make this out to be a bad thing (or at least to a casual observer), when in all actuallity it's a great thing. If delivering the next frame to the GPU is more important to you than compiling the kernel, the kernel will get starved. In Linux and other non-RTOS's, you will run out of time slices because they are being "fair".
This reminds me of the whole VM issue. If you don't have enough memory to complete a job, no VM you have is gonna help you. Likewise, if you don't have enough CPU to complete the job, no schedular is going to help. Where the new VM and RTOS's help is when you are playing your FPS game, you can schedule regular intervals to fill the audio buffer and calculate the next frame as well as do physics calculations. If you don't have enough CPU to do them all, pick the ones that matter most. Linux can pick them in the wrong order and miss a more important calculation getting done on time. No one has actually tested if linux can do more overall because of this, but most of us have a select few tasks actively interacting with us that we would really like to not be interrupted. RTOS can guarantee this at the sake of other processes, but that's a good thing. Win3.1 on the other hand, one unimportant process can not relenquish the CPU.
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