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Java, the Chicken of Tomorrow

The rant I was referring to the other day was from Java, the Chicken of Tomorrow by Miles Nordin:

Sure, there is some association between the imaginary JavaCPU and the Java language. But there is also some association between the real MIPS CPU and the C++ language: modern CPUs are overtly designed with the foreknowledge that they will be judged based on how fast they execute algorithms written in C++. Is the nonexistant Java CPU really uniquely adept at running Java programs, like a Symbolics `Ivory'' CPU is uniquely adept at running Lisp programs? No.

This observation makes me wonder if we wouldn't be better off throwing out Java and writing programs in C, then cross-compiling them for the VAX CPU. Instead of a JRE, we could simply write a VAX emulator for all interesting architectures, and put virtual-VAX sandboxes inside web browsers. VAX insns would become the Language Of The Web. We could standardize a crippled miniature virtual VMS called WebVMS for building into web browsers, to give all these VAXlets access to the network, the local filesystem, a GUI toolkit. We would have VAX-compatible smartcards. There is no reason a VAX emulator can't translate VAX instructions into native-CPU instructions just like a JRE's JIT does. This can be done quite well---like I said, the VAX emulator for the Alpha is faster than any physical VAX CPU. I suspect VAX machine-code would also be similarly compact to Java bytecode, since machine-code-compactness was the biggest priority when the VAX was designed. There is no missing piece to invent or design: we simply agree that, henceforth, all applications will be VAX applications so as to be equally inconvenient for everyone. Voila! Portability!

And when he hits his stride

The most important feature of the Java CPU is that it doesn't exist yet, but it could. Part of Sun's plan to make money from giving away Java was to build Java CPUs. This was a stated plan of theirs, not my speculation. The following is much more speculative.

Sun reasoned that if they could construct computers that ran Java bytecode natively, everyone else would suddenly realize that their JREs were CPU emulators for the computers Sun was selling. I suspect the fastest JavaCPUs would always be emulators, just as the fastest VAXen are emulators running on Alphas, but perhaps Sun could make some slow computers out of physical JavaCPUs that cost less to make than competing emulators of similar speed. The JavaCPU is thus extremely simple, so as to be implementable with minimal silicon and minimal research. Compared to a modern architecture like the Alpha, the JavaCPU looks like something an undergrad dreamed up in the men's room based on the mathematical elegance of two urinal cakes, one stacked upon the other. The JavaCPU idea gives Sun a brief window for a hit-and-run industrial subversion. If Sun can open hundreds of these tiny windows-of-opportunistic-slack, maybe a few of them will pay off. Something like the Alpha matures slowly, with many years of compiler research and successive core revisions abstracted by PALcode: the Alpha is not hit-and-run, and indeed it looks like Digital didn't survive long enough to finish cashing in on the Alpha. A low-end infantile design like the Java bytecode makes business sense in an industry where everyone with a big plan or a big research investment eventually gets screwed over by speculative neck-tie damage and goes bankrupt.

It's an interesting essay/rant. (Incidentally, Stephane has a copy of the original The Chicken of Tomorrow which is also very amusing.)

posted Thu 29 Apr 2004 in /software/languages/java | link

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