Currently, the copy constructor of an AttributeArray is not thread-safe because it doesn't lock the mutex when initializing the variables around performing the copy.

The best pattern I've found to address this is the following:

class Foo {
private:
    Foo(const Foo& other, const tbb::spin_mutex::scoped_lock&)
        : var(other.var) { }
public:
    Foo(const Foo& other)
        : Foo(other, tbb::spin_mutex::scoped_lock(other.mMutex)) { }
};

However, this requires an ABI=7 change.