Multi to the core

In looking at the merging dual-core and upcoming multicore processor firmaments for American Scientist, Brian Hayes goes over the prehistory. That is..the Inmos Transputer and its beloved Occam language compatriot, Danny Hillis and the Connection Machine, and David Gelerntner and the Linda OS. He mentions that these ventures were flattened by the general onslaught of commodity products based on clusters, racks, and Ethernet. Of course the demise of the Soviet Union had a role too.

I have this recollection of Hillis et al suddenly trying to make a living doing filters on American Express transactions – tough slogging after the original Evil Empire packed up.

What are the pivotal issues looking forward? Hayes writes that writing in the mode of parallelsim is just hard for humans. Vendors of hardware and software seldom are so genuine. Super cooled computers, not too practical on desktops, may be the alternative, he says. But don’t hold your frozen breath.

He pens: “Writing correct concurrent programs
is not impossible or beyond human
abilities, but parallelism does seem to
make extreme demands on mental discipline.
The root of the difficulty is nondeterminism:
Running the same set of
programs on the same set of inputs can
yield different results depending on the
exact timing of events. This is disconcerting
if your approach to programming
is to try to think like a computer.”

The mind of the programming humanoid tends to be single threaded. Or, as Hayes writes: You may be able to walk and chew gum at the same time, but it’s hard to think two thoughts at once.

Google seems to have had some success with parallelism – in the age of clusters, and Hayes mentions a paper describing that success. Fairly recently none other than IBM saddled up to Google to address the threading conundrum.

Parallelism to date has been shielded from the everyday programmer by compiler and OS adepts. It has been writ that the massively parallel demon cannot be hidden from the everyday programmer people too much longer. -Jack Vaughan

Multicore chips could bring about the biggest change in computing since the microprocessor – AM SCI

Google and clusters – Labs.GoogleMult

Mashups: Danger when scripts collide

The surge in use of JavaScript and mashups puts greater stress on developers to achieve security within the common Web browser. Even new tools to improve Asynchronous JavaScript and XML (Ajax) interface building can aggravate security problems if they are not handled correctly, according to Douglas Crockford, evangelical architect at Yahoo and crea

read more | digg story