Thank you; the example helped clarify for me. Yes, any time there are shared resources, concurrent tasks can hit synchronization points, and end up bottlenecki

Thank you; the example helped clarify for me. Yes, any time there are shared resources, concurrent tasks can hit synchronization points, and end up bottlenecking on them. Of course, I'd contend that a point of synchronization is a form of serialization, but I agree that the tasks being synchronized would still be described as concurrent (since they don't causally affect their ordering). But such a synchronization is a necessary part of the algorithm you're choosing to use (even prior to SMP support), or it would be completely unnatural to include it. I don't know that it really invalidates the OP's point, that the language didn't remove the bottlenecks you introduced?