Interview with Patrick Viry

Ateji PX: ‘an extension of the Java language with parallel programming primitives.’

Jessica Thornsby

JAXenter speaks to Patrick Viry about the new Ateji PX multi-core language extension and the “multi-core crisis.”

Last week, the first public release of
Ateji PX
went live. Here, JAXenter speaks with Ateji founder
Patrick Viry about the new language extension and programming
environment for multi-core and parallel programming in Java, and
the so-called ‘multi-core crisis.’

JAXenter: What is Ateji PX?

Patrick Viry: Ateji PX is an extension of the
Java language with parallel programming primitives. Unlike library
or preprocessing approaches, this makes parallel programming
simple, intuitive and easy to learn.

JAXenter: The release announcement refers to
the ‘multi-core crisis.’ What is this crisis, and how does Ateji PX
help overcome it?

Patrick Viry: The term “multi-core crisis” has
been coined by chip makers. A couple of years ago, the race for
ever faster chips abruptly stopped because they would dissipate too
much heat and melt down. Since it wasn’t possible anymore to double
the speed of processors every 12 to 18 months, chip makers started
to double the number of cores on the same silicon die.

Nothing really difficult from a hardware point of view, but a
huge software revolution : if you don’t make your programs
parallel, they will be able to use only one out of many available
cores. Until now, it was enough to wait a couple of years to see
your application run faster, not anymore. This has been called
the end of the free lunch” for software

The term “multi-core” crisis refers to the lack of tools and
languages for writing parallel programs, and parallize existing

JAXenter: What existing languages and tools
does Ateji PX leverage?

Patrick Viry: Ateji PX builds upon Java, the
most popular language nowadays, and the Eclipse IDE. If you know
Java and Eclipse, you’ll be able to write your first Ateji PX
parallel program within a half day.

JAXenter: Which parallel patterns are

Patrick Viry: With only a handful of well
designed parallel constructs, Ateji PX is able to express a wide
range of parallel patterns:

- data parallelism (running the same operation on a large number
of data elements, typically used in simulation and high-performance

- task parallelism (decomposing a problem into concurrent tasks,
typically used in server applications.)

- recursive parallelism (decomposing into smaller and smaller

- speculative parallelism (starting a computation before needing
the result.)

- the Actor model (independent actors reacting to input

- data flow (think boxes with input and output wires.)

- stream computing (think database tuples flowing in these
wires), on which Google’s MapReduce algorithm is based.

While different tools had been devised for these different
patterns, Ateji PX provides all of them within one single tool.

JAXenter: What are the advantages of parallel

Patrick Viry: Most people get interested into
parallel programming because it is the key to leveraging the power
of multicore computers. But there are also other reasons for doing
parallel programming:

- Green computing : parallel code on multicore hardware uses
less power than sequential code. This is important for embedded
systems (such as phones) that heavily rely on battery, and for
large data centers that need to contribute to lowering global

- Responsive user interfaces and responsive servers : if the
code is not parallel, it gets unresponsive, stuck or
underperformant. Being able to write parallel code in an easy and
intuitive way is an important step towards having “small parallel
islands” all over the code.

- Algorithmic description : some algorithms require statements
such as “read both input 1 and input 2, in whatever order.” This is
simply not possible to express in sequential languages such as
Java. The programmer must order arbitrarily the statements (such as
“first read input 1, then read input 2,”) at the risk of making the
program block.

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