I see your point, but as a counterpoint, consider that you have two or more distinct data structures, for example several separate linked lists. What if you nee

I see your point, but as a counterpoint, consider that you have two or more distinct data structures, for example several separate linked lists. What if you need to update multiple lists in one atomic operation? With mutexes, you can do this rather easily: either you have one mutex that guards all lists, or you have one mutex for each list and you ensure you always take them in the same order. I would think that qualifies as composing. However, you can't easily compose a lockless algorithm that works on one list to make it work on multiple at the same time.