How to do hardware independent parallel programming?

Question

These days there are two main hardware environments for parallel programming, one is multi-threading CPU's and the other is the graphics cards which can do parallel operations on arrays of data.

The question is, given that there are two different hardware environments, how can I write a program which is parallel but independent of these two different hardware environments. I mean that I would like to write a program and regardless of whether I have a graphics card or multi-threaded CPU or both, the system should choose automatically what to execute it on, either or both graphics card and/or multi-thread CPU.

Is there any software libraries/language constructs which allow this?

I know there are ways to target the graphics card directly to run code on, but my question is about how can we as programmers write parallel code without knowing anything about the hardware and the software system should schedule it to either graphics card or CPU.

If you require me to be more specific as to the platform/language, I would like the answer to be about C++ or Scala or Java.

Thanks

Answer 1

Martin Odersky's research group at EPFL just recently received a multi-million-euro European Research Grant to answer exactly this question. (The article contains several links to papers with more details.)