Data parallel libraries in C/C++

Question

I have a C# prototype that is heavily data parallel, and I've had extremely successful order of magnitude speed ups using the Parallel.For construct in .NETv4. Now I need to write the program in native code, and I'm wondering what my options are. I would prefer something somewhat portable across various operating systems and compilers, but if push comes to shove, I can go with something Windows/VC++.

I've looked at OpenMP, which looks interesting, but I have no idea whether this is looked upon as a good solution by other programmers. I'd also love suggestions for other portable libraries I can look at.

Answer 1

if you want something that is versatile, as in portable across various OS and environments, it would be very difficult to not to consider Java. And they are very similar to C# so it be a very easy transition.

Unless you want to pull out your ninja scalpel and wanting to make your code extremely efficient, I would say java over VC++ or C++.

Answer 2

If you're happy with the level of parallelism you're getting from Parallel.For, OpenMP is probably a pretty good solution for you -- it does roughly the same kinds of things. There's also work and research being done on parallelized implementations of the algorithms in the standard library. Code that uses the standard algorithms heavily can gain from this with even less work.

Some of this is done using OpenMP, while other is using hand-written code to (attempt to) provide greater benefits. In the long term, we'll probably see more of the latter, but for now, the OpenMP route is probably a bit more practical.

Answer 3

You should check out Intel's Thread Building Blocks. Visual Studio 2010 also offers a Concurrency Runtime native. The .NET 4.0 libraries and the ConcRT are designed very similarly, if not identically.

Answer 4

If you're using Parallel.For in .Net 4.0, you should also look at the Parallel Pattern Library in VS2010 for C++; many things are similar and it is library based.

If you need to run on another platform besides Windows the PPL is also implemented in Intel's Thread Building Blocks which has an open source version.

Regarding the other comment on similarities / differences vs. .Net 4.0, the parallel loops in the PPL (parallel_for, parallel_for_each, parallel_invoke) are virtually identical to the .Net 4.0 loops. The task model is slightly different, but should be straightforward.