I've used OpenMP a little bit, and I would probably avoid it for libraries. I might use it to start out an application, since it requires very little code for

I've used OpenMP a little bit, and I would probably avoid it for libraries. I might use it to start out an application, since it requires very little code for dumb parallelism. But if I were making a real library, I would try to abstract the concurrency policy away so the user can control it. This should be trivial by layering the library. Just provide a bunch of single-threaded functions, and then some OpenMP wrappers. Then user can call the single-threaded functions if she wants to do something different. What I don't want is OpenMP baked deeply into the program logic. I think it shares the problem I was talking about. If you have 10 different libraries using OpenMP in an app, and the app is ITSELF multi-threaded, it seems like you have a mess of threads that you have no control over.