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These must be figments of my imagination.

All you need is ability to say something to like "val myiospace = new MMIORange(baseaddr, length)" and "myiospace[42] = x". You might get a drop in speed for bounds checking, but as the compiler/JIT compiler is aware of this MMIORange type it can safely eliminate those in most cases.

Hope your "Period." passes without further frustration.

JX, a java operating system that does what their patent covers, was in development long before they filed that patent application.

These people would beg to get the credit they deserve: http://jxos.org/.

Micosoft Research can't credit this as their inspiration because of the four-letter word (ie Java).

Java is already fragmented. The result of open sourcing Java will actually be consolidation, i.e. killing of competing VMs. And a huge open source test suite will greatly benefit all surviving JVMs, which is a good thing.

How can you not see this?

Javas problem is not that it might get fragmented, the problem is that it IS fragmented. Do something about it! Let Java free!

MS Singularity is just their version of jxos - pure Java OS. Their version is actually somewhat worse than jxos, since that at least includes a functional AWT user interface, simple network stack, nfs server, ext filesystem, and minesweeper (you can even try it in vmware, just download the boot disk image). Last I checked singularity had a command-line only interface. It is equivalent to a school project, but that doesn't mean the approach is wrong... it isn't.

Of course neither are as advanced or usable as Sun's JavaOS... I wish they would open source that! Monolithic unsafe kernels are old hat. They suck in so many ways it isn't even funny.

The classic response of someone who has never actually done any serious kernel work.

Maybe so, but if you are trying to imply I don't know what I'm talking about then that's bullshit. I've had no problems writing complicated code in FreeBSD and Linux kernels -- other than it being in C.

There's plenty of "performance-robbing intermediation" in safe languages AND in C, because of the extraordinary lengths that have to be gone to for simple problems (unnecessarily copying buffers, no callbacks, maintaining complicated memory maps, having to maintain manual memory ownership). You say safe languages don't have direct access to the hardware, but that's misleading. For example, if your driver accesses memory through an object (ie, memory.write(location, abyte)) this would get compiled to just an "if (location >= min || location <= max) *(mem+location)=abyte" for example. Or you replace it with an object that does nothing and it gets completely removed, so there is no check and no overhead at all per write (and no safety).

Also you say "there is no someone else in the kernel". Of course there is. You have 4k or so of assembly that gives access to the hardware-specific stuff (memory space registers, page table flush instruction, interrupts). How much of the "someone else" do you think something like Java uses anyway? The core is pretty much *all* written in java. Check our jxos.org's Java operating system. Run it in vmware and you get a simple network stack, *GUI*, processes, etc. It was written by like 2 guys instead of watching TV. This stuff is doable and plenty fast; that's why I describe you as a "naysayer".

First, Microsoft have a longer history of developing virtual machines for programming languages (in Visual Basic).

Java owes a lot (beyond even that) to MS Research. Don't judge a company by its Operating Systems division..

Finally, you want to claim Microsoft Research are credit-stealing whores over the Java community? Where do you think the idea of objects supporting multiple interfaces for the purposes of inclusion polymorphism (seperated from the nightmare of multiple inheritance that plagues/criples OO-languages) comes from?

No, but if you have vmware or the right hardware you might want to check out JXOS an all-Java operating system. It was done by I think 2 people in their spare time, and it's like 50% of Linux speed at an actual benchmark (nfs filesystem). That's pretty good for two guys writing everything from scratch.

The problem is not the architecture but the OS. The perfomance impact on context switches is mostly in changing the memory space (TBL, cache flush). Just two people developed an OS that runs all programs in the same space, so the processor keeps running at full speed. It can do this because it's written in a safe language (Java, but could be C# or other) so nothing can write to arbitrary addresses.

Despite being written in Java by just two people instead of the thousands that wrote the Linux kernel and optimizing C compiler, it is 50% the speed doing actual work. For comparison, commercial JVMs generate code that ranges from 2x-5x faster than gcj (gcc's java compiler) so this OS could easily be much faster than Linux. The only hold-up is drivers and support for archaic C/UNIX style programs (they should put it into the linux kernel as a module and gradually replace linux code with sane OO code).

You're missing the fact that Microsoft's only weapon against Linux is software patents. They can't win on price since Linux is free. They can't win with features since there are countless super-phreaks out there making their obscure codes. They can't win with DRM unless they can prevent Linux from implementing the algorithm.

Basically without patents Linux will destroy Microsoft. Linux may not win in the end, since it is such old tech (ie uses MMU)... It'll probably be something more like JX, where only two developers created a Java OS that benchmarked at 50% the speed of Linux (it's got an AWT gui and everything... check out the demo disk in vmware). IMO, it could reach twice Linux's top speed with some performance work).

but until one can write an OS kernel in it

One can actually write OS kernels with java, see e. G. http://www.plurix.de/ or http://www.jxos.org/.