deal.II (http://www.dealii.org/) uses the Threading Building Blocks throughout the library and by and large we're reasonably happy with it. We've looked at a few alternatives, in particular OpenMP since everyone seems to be using that for simpler codes, but found them lacking. In particular, OpenMP has the huge disadvantage that its task model does not allow you to get a handle for a task you started, and consequently it is difficult to access the state of a task (e.g. to wait for it finishing) or return values of functions you run on a separate task. OpenMP is primarily good for parallelizing the innermost loops but you gain parallel efficiency by parallelizing the outermost, complex loops, and OpenMP is not the tool for that while the TBB are reasonably good for that.

deal.II uses the Threading Building Blocks throughout the library and by and large we're reasonably happy with it. We've looked at a few alternatives, in particular OpenMP since everyone seems to be using that for simpler codes, but found them lacking. In particular, OpenMP has the huge disadvantage that its task model does not allow you to get a handle for a task you started, and consequently it is difficult to access the state of a task (e.g. to wait for it finishing) or return values of functions you run on a separate task. OpenMP is primarily good for parallelizing the innermost loops but you gain parallel efficiency by parallelizing the outermost, complex loops, and OpenMP is not the tool for that while the TBB are reasonably good for that.